For Internal use Only For Internal use Only

Training Module Study Guide Coating Processes

1. Introduction2. Discussion3. Process Selection4. Eutalloy Model B Torch & UltraJet Eutalloy Torch5. Thermal Spray Overview6. RotoTec 1A7. Terodyn 20008. Terodyn 30009. Castodyn DS 800010. TeroJet AC (HVOF) System11. EuTronic GAP 375 PTA (Plasma Transferred Arc Welding) System12. Safety and Health Considerations

Note: These Modules are intended to be used as a study guide prior to or in conjunction witheach part of the lecture portion of the Powder Training Course offered by the Eutectic Group.Provided is background information and instructions that will aid in learning the detailsprovided in each process manual.Be sure to study and understand the information in the process manuals before proceeding touse the systems.

1. Introduction

Applying the technologies of Welding and Coatings to the best advantage for industry is aunique and important challenge. The recurring expense of maintaining industrial equipmentcan be crippling to a company when traditional approaches are followed. By using availabletechnologies, control is added to the preventative maintenance program. Control thattraditionally was limited to scheduled shutdowns for replacing critical components beforefailure is now extended to increase the service life of parts far beyond that of the originalequipment.

Commonly recognized types of wear are:

1. Abrasion (2-body, 3-body, low stress, high stress)2. Adhesive wear (scoring, galling, fretting)3. Erosion (solid particle, liquid particle, fluid or gas)4. Corrosion (liquids, vapors, and gases)5. Impact and Fatigue6. Cavitation

By using welding and coating technologies it is possible to lengthen the time betweenscheduled shutdowns thereby increasing productivity. The fact that worn components can berebuilt by welding or coating, rather than being written off as scrap adds incremental savingseach time a part is rebuilt. Savings of course, translate into profits.

2. Discussion

Maintenance and repair by welding or coating is not a new concept. However, these conceptsare often underutilized. There is merit to the old saying if it works, dont fix it. This works formany things used by individuals, cars, lawn mowers, bicycles, and such. It does not work inindustry where lost production far outweighs the convenience of not worrying about it until itbreaks.

Exploring an overview of the concept, the following questions are key:

What is the problem? How much does the problem cost? Why is there a problem? Which technology can be used to best manage the problem? When should this technology be used? Who should apply the technology?

The following examples are used to illustrate the concept.

What is the problem?

Part wont work anymore. Part doesnt last long enough. Replacement part is not available.

How much does the problem cost?

Value of lost production. Value of lost business Cost of replacement parts or equipment. Installation costs of parts or equipment.

Why is there a problem?

Parts break. Parts wear out. Parts corrode.

Which technology can be used to best manage the problem?

Welding, brazing, or soldering can fix broken parts. Worn out parts can restored to original dimensions by both welding and coating

processes. The rate of wear can be controlled by process and alloy selection. Wear is inevitable. Proper selection of coating or overlay can often control where

the wear occurs. In this way, parts that are easier to work on can be allowed towear first.

When should this technology be used?

Ideally, during scheduled downtime. As part of the original equipment manufacturing. For emergency repairs.

Who should apply the technology?

The most versatility is realized by on-site application by in-house employees. On-site application by contractors. Parts can be sent out to contractors for application and finishing.

3. Process Selection

The Eutectic Group maintains a database of Approved Application Procedures (AAPs).Literally thousands of solutions to industrial problems are documented, and available asreference materials to support our commitment to improving the performance of industrialcomponents by prolonging their usable life span.

This reduces the amounts of scrap generated by industry, preserves natural resources, andcontrols costs associated with operation of machinery and equipment.

AAPs are available for the entire realm of processes recommended by the Group. Theseinclude the following:

JoiningBuild up overlays

SMAW Stick Welding

Hardfacing overlaysSolid WiresFlux Cored Wires

GMAW Wire Welding (MIG)

Metal Cored WiresJoiningBuild up overlays

GTAW Wire Welding (TIG)

Tool & Die AlloysBuild up overlaysPTAW Plasma Transferred Arc Welding

(EuTronic GAP 375 Powder Welding Process) Hardfacing overlaysBuild up coatingsThermal Spray Coating Fusion Powder Process

(Eutalloy, RotoTec, Terodyn, Castodyn) Hardfacing CoatingsBuild up CoatingsCorrosion Control Coatings

Thermal Spray Coating Cold Spray Powder Process(RotoTec, Terodyn, Castodyn, HVOF)

Wear Resistant CoatingsMetal Filled Build upCoatingsWear Resistant Coatings

Composite Adhesives Abracor(Two part epoxy-composite materials)

Emergency Repair CoatingsFull PlatesCustom Cut Plate

Wear Plates (Hardfacing Weld Overlay on Steel Plates)

Fabricated Anti-wear Parts

AAPs can be searched by different parameters such as: process, part, industry, country, andetc. Confidentiality is ensured by license.

4. The Eutalloy Processes

The Eutalloy Process was introduced by Eutectic in 1963 as a way to braze or overlay usinga metal powder feedstock. Since then it has been refined into one of the most versatileoxyacetylene processes for repairing and protecting surfaces, edges, corners, holes, threadsand key-ways made of most common alloys. In fact the model B system has attachmentsavailable for cutting and standard brazing as well as for the powder process. The Eutalloy

Process uses the Low Heat Input principle developed by the Eutectic+Castolin Institute.

Specially formulated fusible powder alloys with near eutectic compositions are used. Themelting characteristics of theses alloy allow surface alloying to take place well below the meltpoint of the base metal. Thus a fully dense, metallurgically bonded overlay coating can beapplied, quickly and easily.

All of the Eutalloy Systems are engineered to be easy to use and serviceable by the user.The table below summarizes system configuration and features.

System Description FeaturesModel B Basic system Four tip sizes for small to large jobs. Available

attachments for powder overlays, cutting, andstandard brazing.

Model C Water cooled system Two tip sizes for continuous production work, andhigh deposition rates.

UltraJet Up-dated precisionsystem

Seven tip sizes with matching precision gasmixer/aspirator assemblies. Available water-cooledtips. Instant on-off gas trigger for quick, easy ignitionand shutdown.

NewUltraJetModel S

High productionrate system

New tip & gas mixer designs operate at 60-psioxygen and 15-psi acetylene provides more heatand higher feed rates to improve productivity.

The Eutalloy Systems are easy to set up and use. They require oxygen and acetylene gasesproperly regulated to the correct pressure settings. The torch is supplied with reverse flowcheck valves. Oxygen is used to aspirate the powder. This virtually eliminates any chance ofacetylene entering the powder module.

To operate the systems set gas pressures according to the following table and instructions.

Connect the torch to gas supply regulators. Light torch as you would a standard oxyacetylene torch. Crack the oxygen valve

and open acetylene valve turn. Ignite immediately, and adjust valves for proper flame. Recheck pressures at regulators, open acetylene valve fully, and adjust final

flame to neutral with the powder feed lever depressed. Be sure to wear eye protection (shades 3-6 recommended). If a backfire or flash back should occur turn off acetylene immediately and check

all equipment before relighting.

Tip Size Acetylene Oxygen Comments53 Model B 2-3 psi 15-18 psi Fine work, carbide tip available48 Model B 4-5 psi 25-30 psi Medium work, carbide tip available45 Model B 5-6 psi 25-30 psi Larger work, carbide tip availableMulti-orifice Model B 10 psi 50 psi Large work, high spray rate34 Model C Water cooled 10 psi 18 psi Large work, continuous use.A1 UltraJet 7.5 psi 22 psi Brazed carbide extension available.A2 UltraJet 7.5 psi 30 psi Carbide insert tip available.B3 UltraJet 7.5 psi 30 psi Carbide insert tip available.B4 UltraJet 7.5 psi 30 psi Carbide insert tip available.C5 UltraJet 7.5 psi 30 psi Carbide insert tip available.C6 UltraJet Watercooled

7.5 psi 30 psi Carbide insert tip available.

Multi-orifice UltraJet 7.5 psi 30 psi Large work, continuous use.NEW UltraJet Model S5 15 psi 60 psi Highest productivity.

The Eutalloy powder module is designed to fit the module opening on the torch. Remove themodule cap; invert the torch and insert into the module opening with a turn to lock. Thismodule protects powders from contamination, eliminates the need for a transfer funnel andhelps to minimize exposure to air-born powder associated with a filling operation. As anoption, a metallic module (or hopper) with a positive sealing cap is available. Use of properventilation and a respirator rated N-95 or N-100 is required during spray and powder handlingoperations.

Prior to coating, the base metal (part) must be prepared. Degreasing, followed by grinding orblast cleaning is normally used. Some cast iron may be saturated with oil and require heatingor vapor degreasing to remove all traces of oil or other contaminants. Pre-heat the part toabout 400 to 800oF and spray a thin layer of powder, from about 1 standoff distance, to coverthe desired area.

If a thin layer is all that is needed, simply continue heating the coated surface (without feedingpowder) with a slightly carburizing flame. Shortly after red heat is attained, the coating willbecome glassy looking and smooth. This is the fusing point. Do not overheat beyond thistemperature or the alloy will become liquid and sag or run off the surface.

If a thicker layer is required, at the first sign of red heat, move the torch tip to within to and begin applying powder in short bursts while slowly moving the torch over the starting area.Once the fusing temperature is indicated by the smooth glassy looking appearance, begin to

add more powder and to advance the torch in a weaving motion at a speed suitable tomaintain the correct fusing temperature. This process, like any brazing process, is subject tohand, eye coordination. With practice it will become second nature to balance powder feed,travel, and heat to obtain the coating deposit you desire.

When less heat is needed, use a smaller tip. Cutting back the gases to choke the flame willcause the tip to overheat and back fire, or flash back. Generally, coated parts should be slowcooled.

Powders available for use with the Eutalloy process include:

10680 Machineable, build up alloy. HRC 15 10224 Machineable, build up alloy. HRB 90 10185 Machineable, tough, hardfacing alloy. HRC 40 10009 Hardfacing, corrosion resistant alloy. HRC 60 10092 Tough hardfacing alloy for elevated temperature service. HRC 50 10999 Hardfacing alloy with carbides for fine particle abrasion. HRA 80+ 10112 Hardfacing tungsten carbide alloy with best abrasion resistance. 10011 Hardfacing alloy with 80% coarse tungsten carbide.

5. Thermal Spray Overview

Thermal spray coatings can be applied by a variety of methods. Coatings are applied to thedesired thickness at temperatures that do not overly stress or change the base metalproperties. We refer to this as cold-process, meaning that the part should not exceed 500o Fduring coating. Keep in mind that subsequent fusing or heat-treating will affect the base metalproperties. Eutectic categorizes thermal spray powders into the following groups.

One-step self-bonding alloys that bond and build up. Two-step alloys for build up only (require separate bond coat). Spray and fuse (hot-process) alloys for build up and hard facing. Low temperature alloys for corrosion control and part restoration.

A group of powders is available with compositions like those used for the Eutalloy process.Coatings applied with these fusible powders can be heated to the fusing range where they willsolidify to full density and form a metallurgical bond with the base metal. Fused coatings aremore durable than other coatings. However, they require a great deal of heat input for fusing.This often makes fusing impractical on very large parts. Very large parts requiring coatingswith this degree of durability or wear resistance can often coated by PTA welding orconventional welding processes. Remember that there is an order of magnitude differencebetween mechanical bonding (cold-process) and metallurgical bonding (hot-process sprayor welded). That is to say 5,000 psi versus 50,000 psi or more, respectively.

Thermal spray has evolved from feeding a wire through an air assisted oxy-fuel torch, to twin-arc wire systems, combustion powder systems, plasma spray systems and finally high velocitysystems otherwise known as HVOF (High Velocity Oxygen Fuel) systems. All of the Eutecticthermal spray systems currently available can be classified in the combustion thermal spraycategory using powder feed stocks. They include the RotoTec 1A, Terodyn 2000 & 3000,the Castodyn DS 8000, and the Terojet systems. Each system has unique features andcan be targeted toward customers with different needs.

Small and medium sized shops that will work mostly coating shafting can benefit most bystarting out with the RotoTec 1A system. Its low capital cost and very functional, proven,capabilities make it a very attractive package. Its limitations are related to coating rate andthat only a limited range of metallic coatings can be used.

Medium and large sized shops who will have steady coating jobs on a variety of parts canbenefit most by acquisition of the Terodyn 2000 or DS 8000 systems.These offer the ability to spray a wide variety of coating types, including metals, ceramics,polymers and low melting point metals such as babbit and zinc. The Terodyn 3000 systemhas additional advantages for the larger sized shop who specialize in thermal spraying. Itsremote powder feeder with large powder capacity is ideal for big coating jobs and allowsoperation in any position, including overhead or inverted.

Many customers demand the extreme wear resistance offered by Eutalloy powderscontaining tungsten carbide, on large parts. Until the advent of HVOF this was not possiblewithout tremendous heat input and changes to the metallurgy of the parts.Coatings based on tungsten carbide can be applied by the Terojet system at low temperatureswith exceptional bond strength. Tungsten carbides applied by HVOF offer the best resistanceto most abrasion and erosion that is possible in a coating. Pure carbide inserts can be brazedin place and will offer better abrasion resistance and hardness. However, inserts are onlypractical on a small scale before the costs become prohibitive.

The basic procedure for applying thermal spray coatings is summarized as follows:

1. Surface cleaning to remove grease, oil, paint, or previous coatings.2. Surface preparation to remove damaged base metal and undercut the area to

accommodate the added coating dimension.3. Masking may be required before grit blasting to protect areas that are not to be

coated.4. Surface roughening to increase the available surface area for bonding and to

provide an anchor pattern to lock the coating in place. This can be done bythreading, grinding or by the preferred method, grit blasting. Grit blasting with 24grit aluminum oxide (corundum), illmenite, or 16 grit angular chilled iron give thebest results and the greatest safety factor.

5. Masking may be required prior to coating. Eutectic hi-temp tape, shadowmasks, Eutectic Solution 103, or other suitable means can be used.

6. Spray torches with adjustable powder feed rate control should be checked beforestarting the job. Spray rate should be within 10% of the rate shown in parametertables.

7. Preheating, generally to between 150oF and 300oF depending on the partgeometry and the powder being used. 200oF is a safe temperature to beginalmost all coatings. Ceramics and polymers being the notable exceptions.

8. Apply coating to corners or edges first. Angle the torch to wrap coating aroundedges. Cover the balance of the part with the bond pass or bond coat.

9. Build up the coating by making multiple overlapping passes. The coating qualitywill be best when applied in thin layers. Traverse speeds and/or rotationalspeeds should be set to apply coating at a rate of less than 0.004 thickness perpass. Traverse speeds on flat parts should be on the order of 3 to 6 per second.Rotational speed of cylinders should be between 150 and 200 sfpm (on smallerdiameters this may be lowered to 75 sfpm) with a travel rate of 0.125 to 0.25per revolution.

10. Maintain temperature below 500oF, pause to allow coating / part to cool whenneeded. Use of auxiliary cooling air is recommended.

6. The RotoTec 1A

The RotoTec torch was introduced by Eutectic in 1971. Over the years the design haschanged from the originally patented model I to the model II and to the current model, the 1A.The model 1A is designed to apply metallic alloys (except zinc, aluminum and babbit) includingthe self-bonding one step powders. A conversion kit is available to upgrade the older models.

The RotoTec 1A is affordable, simple to use, and very effective for rebuilding shaft bearingareas. Powders are packed in modules that fit on top of the torch. Powders feed by gravityinto the flame, which heats and propels particles onto the part.

To operate the torch, follow these instructions:

Connect the torch to gas supply regulators. Set oxygen regulator to 20 psi and acetylene regulator to 8 psi. Light torch as you would a standard oxyacetylene torch; crack the oxygen valve

and open acetylene valve turn. Ignite immediately, and adjust acetylene and then oxygen to full flow. This will

give a slightly oxidizing flame Be sure to wear eye protection (shade 5 or higher). If a backfire or flash back should occur turn off acetylene immediately and check

all equipment before relighting.

Powders available for use with the RotoTec process include:

19121 General-purpose one-step powder. 19122 Machinable general-purpose one-step powder. 19131 Machinable corrosion resistant one-step powder. 19132 Hard, corrosion resistant one-step powder. 19171 General-purpose bronze one-step powder.

Spray and fuse powders can also be applied with the RotoTec system:

13494 Nickel chrome boron HRC 40 13495 Nickel chrome boron HRC 50 13496 Nickel chrome boron HRC 60

The following two-step powders can also be used to build up parts. They must be used onlyafter application of the bond coat powder UltraBond 50000.

29011 316 stainless steel (Austenitic) HRB 90. 29012 400 type stainless steel (Martensitic) HRC 35. 29021 Durable nickel chrome aluminum alloy HRC 32. 29061 Machinable bronze powder HRB 65. 29077 Low alloy steel powder HRB 85. 29096 Machinable nickel chrome alloy for thick build-ups HRB 82.

7. The TeroDyn 2000

Eutectic+Castolin introduced the TeroDyn 2000 in the early 1980s as the CastoDyn 2000,which was an improved version of the Rotoloy torch. In 1984 the design was modified andthe TeroDyn 2000 series 2000 was born. It has the most value based on cost andperformance of any torch available in any market worldwide. Some European Countries havestandards that do not allow acetylene to be used above 10 psi. TheDS 8000 system is used exclusively in these countries.

The TD 2000 is a thermal spray work horse. The torch body is forged bronze, precisionmachined and plated. It is built to last, and does, with many of the original units still operationafter 20 years or more. Designed to be the most versatile powder alloy delivery systemavailable. Its features, controls, accessories and capabilities are impressive. Understandingthe following illustration of the system, and description of functional parts, is essential prior tolearning about its more advanced accessories, features and benefits.

1. MEGAPAK MODULEStandard packaging for most powder alloys. Locks into theModule Adapter (item 2) by a quarter of a turn.

2. MODULE ADAPTERMounts MegaPaks to the delivery system. The Basic Kit comeswith 2 adapters. The material being deposited and coating ratewill determine the appropriate adapter.

3. POWDER ALLOY ON -OFF CONTROLStarts and stops the flow of powder into the delivery system.Green dot indicates alloy is feeding, red dot indicates no feed.

4. ASPIRATOR PLUGAccess plug for cleaning powder alloy aspirator. Must be tightat all times.

5. T-VALVETransport Valve-controls the flow rate of the carrier gas andpowder alloy. Valve position varies with material being applied.

6. O-VALVEOxygen valve-Controls the flow of oxygen into the flame. It isadjusted until the number indicated on the FM-1 Flowmeteragrees with the figure published in the Coating Tables.

7. A-VALVEAcetylene valve-Controls the flow of acetylene into the flame. Itis adjusted until the number indicated on the FM-1 Flowmeteragrees with the figure published in the Coating Tables.

8. OXYGEN INPUT FITTINGRight-hand thread connection for oxygen line includes Flo-SafeReverse Flow Check Valve.

9. ACETYLENE INPUT FITTINGLeft-hand thread connection for acetylene line includes Flo-Safe Reverse Flow Check Valve.

10. GAS ON-OFF TRIGGERControls the flow of oxygen & acetylene. In the forward positiongases are flowing, in the backward position the flow of bothacetylene and oxygen are stopped.

11. TOOL POST MOUNTING STUDFor machine mounting the delivery unit.

12. GAS MIXER ASSEMBLYCombines oxygen and fuel gasses to produce a combustiblemixture for the nozzle.

13. NOZZLE RETAINING NUTSecures nozzle to gas mixer.

14. NOZZLEForms proper flame and introduces materials into the flame.Two nozzles are supplied with the Basic Kit (RL 200 and RL210); use the nozzle specified in the Coating Table for thematerial being applied.

15. TWO-PIECE HEAT SHIELDUpper heat shield protects MegaPak, lower heat shield protectsthe operators hand from the heat generated during continuouscoating operations.

16. LOCK NUTSecures the gas mixer assembly to the delivery unit

Only genuine Eutectic powders are recommended for use with the TD2000. However, overthe years it has been found that, because the torch is so versatile, parameters can bedeveloped for almost any powder. Technical service can offer advice on what is possible.

Installation of the TD 2000 is somewhat more complicated than either the RotoTec 1A or theDS 8000. Due to the volume of acetylene used, cylinders must be manifolded to ensure thatthe system functions safely. To ensure coating quality given the wide variety of powders andaccessories an inline flow meter for oxygen and fuel, and compressed air are required asshown in the following illustrations.

The TeroDyn 2000 System Complete Kit contains everything needed to begin coating parts,except the powder. To operate the system set it up as above.

Find the parameter settings for the powder to be used in the process manual.Print this table for reference.

Attach the nozzle and RotoJet specified. If the RPA-1 is being used the air mustbe turned on before lighting the torch or it may damaged by melting.

Make sure the gas on-off trigger is in the off (back) position and the gas valvesare closed.

Set the oxygen and fuel gas regulators to the required pressures. Open the powder container and attach the correct module adapter (yellow/red or

aqua) to the powder container. Make sure the powder on-off lever is off (showsred indicator).

Set the T-Valve to the specified click setting range. Anytime the T-Valve ischanged be sure to re-check the oxygen flow and adjust as needed.

Crack the oxygen valve and open the fuel valve to turn and ignite. Increasefuel then oxygen so the flow meter reads the values specified in the table.

Check that there is suction at the powder inlet on top of the torch using yourfinger. If not check to see that the T-Valve is not set on zero.

Invert the powder container and attach to the torch by sliding it into place. If the air to the RotoJet is off, turn it on and check that the pressure is set as per

the parameter table. Be sure you are wearing the shade 5 safety glasses included in the kit before

starting to spray. To start spraying, push the powder feed lever forward so it shows green. Remember to check surface preparation before coating. Remember to check powder feed rate at the beginning of each shift or job.

Features and benefits of the TeroDyn 2000 system

Safety

Critical seals are O-rings Any leaks easy to find and fixMixed gas path is short Less chance of flash-backPositive flow of oxygen carrier gas Prohibits presence of fuel gas in powder moduleReverse flow check valves included Prevent any back flow of gases into gas suppliesGas on / off control lever Allows instant shut off of oxygen and fuel with

one control

Reliability

Rugged construction Service life of decades rather than yearsPrecision powder transport valve Consistent powder feed ratesIn-line flow meter Makes setting flame accurate and repeatable.

Versatility

Several precision multi-orifice nozzles Control of heat transfer characteristics expandsthe range of coating materials that can be used

Air circuit RotoJet attachments Flexibility to increase powder velocity, focusspray pattern and cool the part

LT Air Shroud Allows low melting point metals and polymersto be applied

LT Extender Allows coating of internal diameters or hard toreach places

Module adapters Two adapters allow control of all powdersincluding ceramics, metals and polymers.Allows out of position coating up to 75 above orbelow horizontal

Tool post stud and attachment Easy to mount torch on lathe tool post or otherpositioner

Multiple fuel gas operation Capability to use acetylene, MAPP, propylene,propane, natural gas or hydrogen to loweroperating costs or for safety and convenience

Powders available for use with the TeroDyn 2000 (and the TeroDyn 3000) system include,but are not limited to:

Self-bonding one step alloys

21021 Multi-purpose material 21022 Machinable build up 21023 Iron base machinable 21031 High temperature service 21032-S Hard corrosion resistant 21071 General purpose bronzeSpray and fuse alloys

23005 35% Tungsten carbide - coarse 23045 Nickel chrome boron HRC 59 23065 Nickel chrome boron corrosion resistant 23075 40% Tungsten carbide - fineHigh temperature materials (ceramics)

25010 Aluminum oxide 25030 Alumina 87 Titania 13 25040 Titanium dioxide 25050 Chrome oxide 25060 Alumina 60 Titania 40 25088 Zirconia 70 Alumina 30

Two step build up alloys

29011 300 type stainless steel 29012 400 type stainless steel 29061 Aluminum bronze 29096 Nickel chrome iron 29123 75% Tungsten carbideLow temperature materials

29210 Aluminum 12 silicon 29230 Zinc 29240 Babbit (tin, grade 2) 1960 Zinc, bulk pkg. 1961 Aluminum 5018 Nylon 11, white EverTuff Methacrylic polymer

8. The TeroDyn 3000

The TeroDyn 3000 System was developed concurrently with the 2000 series. It uses thesame bronze forging and common parts. In fact, the TD2000 can be upgraded to the 3000model. The following photo shows the TD3000 and the 5102 powder feeder

Notice modifications to the torch body. The module adapter saddle, the T-valve and the handleare not used. An adapter to accept the external powder feed hose is added and the handlechanged to include a powder start/stop switch. All of the attachments available for the TD2000will fit the TD3000.

Set up of the TD3000 is quite similar to that for the TD2000. The flow meter has a highcapacity fuel gas tube and the system comes with two 25-foot twin gas hoses instead of thestandard 12-foot hoses supplied with other torches.

To begin producing coatings the following are required:

TeroDyn 3000 Basic Kit (#4484757) Carrier Gas Regulator (4615000) Powder

Step-by-step operational procedures are available in the Process manual for the TD 3000 andTecFlo 5102 powder feeder. During the hands on portion of the TD 3000 training allprocedures as well as maintenance will be thoroughly explained demonstrated and practiced.

The principal of operation of the feeder is the fluidized bed. Carrier gas is divided into twostreams. Both fluidizing and transport streams are controlled by the carrier gas flow meter.Adjusting the pressure of the carrier gas in the powder hopper sets the powder spray rate.This is regulated, along with the gas flow rate, on the front panel of the 5102 feeder.The powder feed parameters have been developed using argon as the carrier gas. This wasdone because the 5102 and 7102 are also used for plasma non-transferred arc thermalspraying. The recently discontinued Eutectic Plasma 5000 system used argon as the primaryplasma gas and hydrogen as the secondary gas. Argon was used as the carrier gas forconvenience.

Plasma Non-Transferred Arc: Manual coating of a tube-sheet for protection against high temperature oxidation.

When using with the TD 3000 it is desirable to utilize nitrogen as the carrier gas because it isabout 1/3 the cost of argon. Due to the physical nature of argon it is able to transport morepowder on a pound per cubic foot per hour basis. Therefore it is very important to verify thespray rate before starting a coating job. A more detailed description will be presented duringthe hands-on training session for powder products and equipment.

Note that an important feature of the DS 8000 is that it can be adapted to utilized the 5102feeder. This capability gives the DS8000 most of the benefits found in the TD 3000 in aneasier to set-up and use package.

Features and benefits of the TeroDyn 3000 system

SafetyCritical seals are O-rings Any leaks easy to find and fixMixed gas path is short Less chance of flashback.Positive flow of carrier gas Keeps powder delivery hose from clogging and

ensures that fuel gas can never back up into thepowder hopper.

Reverse flow check valves included Prevent any back flow of gases into gas supplies.Gas on / off control lever Allows instant shut off of oxygen and fuel with one

control.Quick disconnects with O-ring seals Prevents the powder hopper from being over

pressurized.Low voltage remote switching tostart and stop powder feed.

In case of electric shock voltage has been steppeddown from 115V to 12V.

Reliability

Rugged construction Service life of decades rather than years.No moving parts in powder feeder Less parts to wear and be replaced.In-line flow meter Makes setting flame accurate and repeatable.Meets US Military Specifications(Mil Std 2138 & 1687)

Quality, traceability, and performance is backed up byextensive research and testing

Color coded inlets to powderhopper

Ensures correct connections for proper operation ofpowder feed.

Versatility

Several precision multi-orificenozzles

Control of heat transfer characteristics expands therange of coating materials that can be used

Air circuit RotoJet attachments Flexibility to increase powder velocity, focus spraypattern and cool the part

LT Air Shroud Allows low melting point metals and polymers to beapplied

LT Extender Allows coating of internal diameters or hard to reachplaces

External (remote) powder feeder Allows coatings to be applied in any position by handor robotically.

Tool post stud and attachment Easy to mount torch on lathe tool post, positioner orrobot.

Multiple fuel gas operation Capability to use acetylene, MAPP, propylene,propane, natural gas or hydrogen to lower operatingcosts or for safety and convenience

Multiple switching control 5102 or 7102 feeders can be used for combustion orplasma spraying.

Other features

Can deliver up to 140,000 Btu/hr Allows coating rates of up to 45 lbs/hour.Fluidized feeder design Metal, polymer and ceramic powders can be applied,

even when the powder is not free flowing or is to fineto feed by gravity or venturi.

Large powder feeder capacity Ideal for extended use and large coating jobs.Dual powder pick up tubes on allhoppers

Allows use of two TD3000 torches at the same time(slaved) with the 5102 feeder.

7102 Feeder available Allows use of two torches (or two pairs of torches)operating independently

9. The CastoDyn DS 8000

The DS 8000 thermal spray system is an innovative redesign of the RotoTec 800. Itincorporates a user friendly modular design concept. There are four standard spray modules(SSMs). Each is used specifically for a certain group of powder products. A durable carryingcase keeps all components organized and well-protected during transport or storage. Use ofprecision laser drilled orifices in both gas mixing and powder delivery components ensureconsistent results without the need for an inline flowmeter. Optional accessories include twomodels of spray and fuse lance attachments, an extension neck for coating internal diameters,and fittings to allow use of a remote powder feeder such as the TecFlo 5102.

The DS 8000 can apply the full range of powder alloys supplied by Eutectic for conventionalcombustion thermal spraying.

Features and benefits of the CastoDyn DS 8000 system

Safety

Critical seals are O-rings Any leaks easy to find and fixMixed gas path is short Less chance of flash-backPositive flow of oxygen carrier gas Prohibits presence of fuel gas in powder moduleReverse flow check valves included Prevent any back flow of gases into gas suppliesGas on / off control lever Allows instant shut off of oxygen and fuel with

one controlOperates at 10 psi acetylenepressure

Greater safety factor since acetylene becomesunstable above 15 psi and allows safe operationwithout requiring manifolded acetylene cylinders

Reliability

Laser drilled precision orifices The most consistent powder and gas feedrates possible

Modular design principle Easy operation, fewer variables to adjustLight weight Less operator fatigue leads to better

coatings and consistent productivity

Versatility

Four Standard Spray Modules(SSMs)

Each module optimized for a specificgroup of powders (gas mixer, nozzle,and air focus attachment)

Extension neck Allows coating of internal diameters orhard to reach places

Module adapter A single adapter with six settings allowscontrol of feed rate for all powders,including ceramics, metals and polymers

Spray and fuse attachment For PTA quality deposits with lowercapital expense.

External powder feeder plug in Good for out of position coating and longspraying runs.

The DS 8000 is a Swiss design made in Europe, and has, for the last several years beenavailable in North America. We rarely keep more than one of these systems in stock in theUS, so take this into consideration when accepting an order.

10. TeroJet Model AC

The TeroJet Model AC is a new generation High Velocity Oxy Fuel powder spray systemdesigned to apply high quality carbide and metallic coatings. The system is simple in design,efficient in operation, and easy to use and maintain. This combination of features makes theTeroJet AC suitable for both production, machine mount applications, as well as, for hand-held occasional use.

The TeroJet has been designed to be as economical as possible for a true HVOF system.Several features make this possible. First, the torch is air cooled so there is no need for awater pump. Air-cooling simplifies the design of the torch making it less expensive to produce.Second, the torch uses compressed gas as the fuel, typically propane or propylene. Kerosenebased systems require an expensive high-pressure pump plus controls to balance the oxygenand kerosene. Lighting is done manually, eliminating the need for an internal ignition systemthat only adds cost and complexity to the system. The result is a system with a lowcapitalization cost and a low hourly operating cost.

The TeroJet torch uses a novel air cap design to choke the gas flow thereby generating ahigh gas exit velocity. In its operating mode seven shock diamonds are visible in thecombustion gas stream. A high combustion gas exit velocity insures that the coatingsproduced will be dense and low in porosity, will exhibit a high microhardness and associatedresistance to abrasion and will be well bonded to a properly prepared base material.

The powder and carrier gas enters the torch axially. This feature insures efficient heating andacceleration of the powder coupled with minimal wear of the internal parts of the torch nozzle.The use of a nozzle with air cap as compared to a long barrel typical of kerosene systemsminimizes loading of the powder onto the internal parts of the torch. Interrupting the sprayprocess to replace worn or clogged barrels can be costly and time consuming. The design ofthe TeroJet AC torch virtually eliminates this problem.

Regulated flows of oxygen and fuel gas are delivered to the torch in the correct proportionsand a flame is developed. Compressed air restricts the flame, cools the torch and blasts thepowder particles to produce a fine, high velocity spray. The combination of the nozzle design,air cap design and high pressure compressed air create the supersonic gas stream asevidenced by the visible shock diamonds.

The system includes a highly precise, rotating disc powder feeder that accurately and reliablydelivers powder to the torch where it is axially fed into the combustion gas stream. Theinclusion of regulators and gas flow meters designed to match the requirements of the torchinsure that process parameters are tightly controlled.

The system is capable of applying tungsten carbide, chromium carbide plus metallic powderblends, metallic and fusible powders. Further, the system can accommodate both 45 + 15mand 53 + 20m size powders, the two most common size ranges commercially available.However, the finer, -45 + 15 m range powder is preferred as it will yield denser coatings.Typical powder spray rates for the TeroJet AC are 5 lb/hr for carbides and up to 8 lb/hr formetallics. The nominal deposit efficiency is 70%.

The Model PF 700 powder feeder is the latest in a series of designs specifically tailored for thethermal spray process. The system is capable of delivering a steady, non-pulsating supply ofpowder to the torch. The PF 700 operates on a volumetric feed principle. At the bottom of thepressurized canister there is a rotating metal disc (slotted wheel) mounted off center withrespect to the canister. A given volume of powder fits into each slot and as the disc rotatespast the exit port, the powder is fed into the powder hose and then to the torch. The feed rateof the powder (g/min, lb/hr, etc.) is governed by the rpms of the rotating disc. The disc isdriven by a precision control, geared, variable speed AC motor and the rpm is displayed on theLED located on the control console front panel. The actual rpm of the disc equals the LEDdisplayed reading divided by 100.

Powders suitable for use with the TJ AC system include the following:

Carbides

55588T 88% WC + 12% Cobalt 55588VF 88% WC + 12% Cobalt (finer particle size) CPP 2506 83% WC + 17% Cobalt 55575 75% Chromium Carbide + 25% Nickel Chromium alloyMetals

55116 316 type stainless steel 55125 Nickel alloy 625 55396 Nickel Chromium Boron alloy (use as sprayed or fused)

11. EuTronic GAP 375 PTA Welding System

In the late 1970s Eutectic launched the its first plasma transferred arc welding systems in theUSA. These were imported from Castolin + Eutectic in France. While the Servomatec 1 and2 were state of the art at the time, they were also bulky systems best adapted to fixedinstallations. By the mid1980s Eutectic redesigned the French system and startedproduction. Success of the US GAP System was limited due its lack of portability and severalminor design flaws, which required excessive warranty service. Production was halted and amajor redesign program begun.

In 1988 after extensive field testing, the first EuTronic GAP 375 systems rolled off theproduction line. Major advances in inverter-converter power source technology reduced thesize and weight of the system. Patented fluidized powder feeding, a solid-state programmablecontroller, and Kooltronic water cooler round out the system.The GAP 375 System is capable of meeting the requirements of the United States Military. Ithas been supplied for Naval Shipyard use as per Bid Solicitation Contracts as governed byDefense General Supply Center (DGSC) purchase order.

The GAP 375 system is compact and, for hand-held operation is easily as portable as the twocompressed gas cylinders required for operation. On-going design was finalized with theadvent of several models of welding torches. These fill the needs of almost all applicationsthat are practical in the scope of both OEM and M & R sectors of industry.The GAP system functions by having argon carry a controlled amount of powder alloy into anargon 7% hydrogen shielded, transferred arc plasma column. The result is a precise welddeposit with minimal heat affected zone and low dilution of the weld by the base metal.

EuTronic GAP System 375 Torches. From top to bottom: the E-90, 200, 220HP, 250, and 300HP torches.

The high frequency (HF) between the anode and cathode (tungsten) creates a pilot arc whenthe system is started. When the torch is brought into position above the work piece the arctransfers and the controller ramps the power and gas flows up initiating the plasma arc columnformation. Powder can be started manually or automatically started by the controller asdesired. The illustration below serves as a basic summary of operation.

The basic system includes the hand-held E-90 Torch. For practical purposes this functionsvery similar to a TIG Torch that welds with powder instead of a rod. There are two mainadvantages to welding with powder rather than wire or rod.

Powders can be made from materials that cannot be drawn into wire or rod. Thisincludes Tungsten carbides, Chromium carbides, and special formulations forwelding on cast iron and bronze.

Single pass deposits can often be used and can be more uniform in cross-section than wire welds for easier finishing with no slag to chip.

Conveyor Screw as welded with the GAP 375 System

Stick welding and MIG welding often require 2 or more weld passes before a hard-facingoverlay will reach the optimum hardness and wear resistance. This is due to the volumepercentage of dilution with the base metal. Generally the higher the percentage of dilution thelower the deposit hardness and the greater the heat affected zone. This is illustrated belowwith comparable cobalt base alloys, by process.

Deposits and the low carbon steel base metals below are acid etched for contrast

Oxy-Fuel Gas Weld: 2 lbs/hour with 1% Dilution

PTA Weld: 4 lbs/hour with 4% Dilution

SMAW (stick welding): 3 lbs/hour with 38% Dilution

GMAW (MIG welding): 5 lbs/hour with 31% Dilution

Features and benefits of the EuTronic GAP System 375

Operates on multiple phase or voltages. Custom wiring not usually required.Extremely stable weld current over theentire ranges (10 375 Amps).

Lightweight and compact, hand-held ormachine mounted capabilities.

Perfect for on site jobs, mobile platformsand fixed robotic installations.

Built-in safety sensors monitor gas flowsand cooling water flow.

Minimizes cost of repairs due to operatorerror.

Uses powder alloys, not wire or rod. Gives a wider variety of coating solutionsto best control the wear process. Thisleads to better over-all cost effectiveness.

Applies thin (1/16) or thick (3/16) coatingdeposits in a single weld pass faster thanis possible with TIG or Oxy-Fuel welding.

Yields better productivity.

Powders suitable for use with the GAP system include, but are not limited to:

Gas Atomized alloys

Stainless steels (16300LC, 16410) Nickel-base alloys (16801, 16804, 16805) Maraging steel (16550) Tool steels (16725) Cobalt-base alloys (16001, 16006, 16012, 16021)

Water Atomized alloys

Nickel Silicon Boron (5056) Nickel Chrome Boron (16494, 16495, 16496)

Blends of Metallic and inter-metallic powders

Ni-Cr-B plus Tungsten carbide (16112, 16113) Ni-Si-B proprietary blends (16220, 16221, 16227) Nickel alloy plus Chromium carbide (16114)

Special compositions or blends can be custom made, or made to industry specifications asrequired. Custom-made alloys are subject to minimum order requirements and/or specialpricing and/or special delivery terms and conditions.

DANGER: When Arc Welding, Plasma Transferred Arc Welding or Plasma Non-Transferred ArcThermal SprayingELECTRIC SHOCK CAN KILL

IN CASE OF EMERGENCY CALL FOR MEDICAL AID Do not touch live electrical parts. Wear dry insulating gloves in, good condition, and protective clothing. Properly install and ground the equipment according to the manufacturers

instructions and federal, state and local codes.

Warning: Fumes and Gases can be dangerous to your health. Medical studies suggest thatLung Damage and/or CNS effects can result from exposure to welding fumes andgases. Brazing, soldering, and thermal spraying may have similar effects. Keep your head out of the fumes. Use enough ventilation, exhaust at the source, or both to keep fumes away

from your breathing zone and the general area. Wear correct eye, ear, and body protection. Before use, read and understand the manufacturers instructions, Material

Safety Data Sheets (MSDSs), and your employers safety practices.

Warning: Light rays, heat rays (ultraviolet and infrared radiation) and sparks from the arc orflame and hot metal can injure eyes, burn skin and may ignite combustiblematerials in the area. Do not look at an electric arc or thermal spray stream with unprotected

eyes. Wear safety glasses with UV protective side shields in addition to a proper

welding helmet with filter plate. Choose glasses, helmet and filter plateaccording to ANSI Z87.1.

Protect exposed skin with adequate gloves and clothing according to ANSIZ49.1.

Remove combustible materials within 35 feet of working area. Do not weld, braze, solder or thermal spray in presence of flammable

vapors or on a container that has held flammable or unknown materials. Keep a charged fire extinguisher nearby, and know how to use it.

Warning: It is possible that the Threshold Limit Values (TLVs) of some of the ingredientsand/or by-products formed during the normal use of some products and/orequipment, will be exceeded without exceeding the TLV for general welding fume,some of these may be carcinogenic according to some agencies. Use engineering controls and personal protective equipment to keep exposure as

far below the TLV as possible. If you are unsure of ventilation or adequate protection, contact your supervisor

before proceeding.

Due to the fact that Eutectic Corporation has no control over how, or where, our products andequipment are used, or whether they are used according to our instructions, we recommend thatemployers consider implementing into their safety practices the following, as a general guideline,

to promote workplace safety as it relates to the products and processes used for brazing, soldering,welding, heating, cutting, gouging, thermal spraying, sealing and machining or grinding:

Caution: If at anytime you experience--difficulty breathing, seeing, or hearing; dizziness, eyeor skin irritation, or nausea: Stop welding, brazing, soldering, or thermal spraying, etc. or remove

yourself from the area then Check all protective equipment and engineering controls and Inform your supervisor.

Do not resume the operation until a cause is determined and corrected.

Oxy-Fuel Thermal Spraying

Hazardous Decomposition or By Products: Fumes, gases and dusts given off during heating and thermalspraying of metallic parts cannot be classified simply. The composition and quantity of these aredependent upon the type of torch used, the powder spray rate, geometry of the part and upon the operatormaintaining the correct spray distance from the work piece. Other conditions which also influence thecomposition and quantity of the fumes, gases, and dusts that workers may be exposed to include; thenumber of workers and the volume of the work space; the quality and amount of ventilation; the position ofthe workers head with respect to the fumes generated; the presence of contaminants in the atmosphere(such as chlorinated hydrocarbon vapors from cleaning and degreasing activities).During thermal spray processes, the fume and gas decomposition products generated are different inpercent and form from the ingredients listed in Section 2. Decomposition products of normal operationinclude those originating from the volatilization, reaction or oxidation of the materials shown in Section 2,plus those of any atmospheric vapors, gases or dusts that may be present at the time.Reasonably expected constituents of the fumes gases and dusts produced may include: complex metallicoxide dust, gaseous reaction products including combustion of ambient atmospheric contaminants,carbon monoxide, carbon dioxide and condensing metallic vapors of the ingredients listed in Section 2.One recommended way to determine the composition and quantity of fumes and gases to which workersare exposed is to take an air sample in the workers breathing zone. See ANSI/AWS F1.1 and AWS F1.3Evaluating Contaminants in the Welding Environment A Sampling Strategy Guide which givesadditional advice on sampling. Both publications are available from the American Welding Society, P.O.Box 351040, Miami, FL 33135.

Route(s) of Entry: Primary route is inhalation of fumes, gases and dusts given off during heating andthermal spray process, the cutting and grinding of thermal spray coatings, and inhalation of dust duringpowder handling operations. Skin contact, eye contact, and ingestion are possible when fumes condenseand dust is present. Skin and eyes must be protected from the radiation spectrum present during thermalspraying. The fumes associated with heating and welding or the cutting and grinding of welded metal canbe dangerous to your health and overexposure can cause damage to nervous system, lungs and/or otherorgans, thermal spraying may produce similar effects. Use adequate ventilation to keep below exposurelimits. Keep fumes and gases from breathing zone. Keep the workers head out of the fumes. The ACGIHrecommended general limit for Welding Fume and nuisance dust, not otherwise classified is 5 mg/m3 and10 mg/m3 respectively. Thermal spraying may produce similar fumes. The threshold limit value for someingredients could be exceeded without exceeding the threshold limit value for general welding fume. Metalfume fever, eye damage, burns, and allergic reactions are significant hazards during thermal spraying.Aggravation of preexisting respiratory conditions may occur in some workers. Appropriate personalprotective equipment must be used.

Recommended Reading:

SAFE PRACTICES IN THERMAL SPRAYINGPublished by AMERICAN WELDING SOCIETY550 N.W. LeJeune Road, Miami, FL 33126

ContentsIntroductionDiscussionProcess SelectionEutalloy ProcessesOverviewRotoTec 1ATeroDyn 2000TeroDyn 3000CastoDyn DS8000TeroJet ACGAP 375Safety