bars proyect

8/8/2019 Bars Proyect

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Bars classification Anode load

WEEK 36

El Salvador


2/24

P roject Pu rpose

Set the bars to be u se as tooling andanode dimensions.

Detect bars in poor condition and get themou t of prod u ction.


3/24

P owder MixingPu rpose

To prepare the tantal u m powder to beprocessed

To increase the flow of tantal u m powder Check the Mechanical properties of thepowder

ConditionsRelative h u midity: 40% - 55%Air extraction


4/24

O bservations

Why The powder need a Binder?Beca u se this helps the flow of powder

Aid to l u bricate the tooling

The mixing process consist in add a Binder to the Virgin powder, thefirst mixing is done man u ally on a stainless steel pot.

The binder u sed:

1. Stearic acid ( Tantal u m powder)2. P EG (Niobi u m powder)3. PX (Niobi u m powder)4. PX + Syntamin ( Tantal u m powder)


5/24

Why we p u t the powder into a blender ?

Beca u se The V-Blender providehomogeneity to the powder mixt u re.


6/24

Mesh: P articles Size distrib u tion inside thepowder.

Scott Density: Determines the ability that hasthe powder to fill a cavity.

Flow : Meas u re the velocity that has thepowder to flow by the action of the gravity .

CRUSH STRENGHT: This test determines thebreakage force (kg-F).

MIXING AQL


7/24

2. PRESS ING

Pu rpose:

To P ress the Tantal u m powder in to anode of defined

shape u sing a HABERER press.Give a pressing density to the anode

Conditions

Temperat u re room: 20C to 25CRelative h u midity: 40% to 55%


8/24

Description

P ressing P rocessMechanism poweredby an electric Motor.Tooling can give 3anodes per cycle.The Haberer gives 156

anodes per min u te.


9/24

O BSERVATI O NSThe low press u re line indicates the zone where the anode

is str u ctu rally weak.

how we can decrease the effects of low

pressu

re line?It mu st be between (50% -75%) of the length of theanode.

To minimize the effects of low-press u re line is necessary toens u re that the wire crossesthe line.


10/24

P ressing AQL

Visu al test with a microscope: search s u rface defectsand wire damage.Anode weight ControlVerification of dimensions of anodes with Shadowgraph:Low press u re line u sing Ultraso u nd: Check the Locationof line.


11/24

WA SH DE- LUB E

Pu rpose

Remove the stearic acid.

MachinesAUTO WASH DE-LUBE (M O RRIS AUT O MATIO N)


12/24

O BSERVATI O NS

The process of WASH de -LUBE consist in sevenwashes.The water m u st be at 85C +/- 5C, the temperat u re aidsto dil u te the binder.

Wash Sol u tion

First and Second Ca u stic soda 32%Third and Fo u rth Des-ionized water Fifth Nitric acid 17%

Sixth and Seventh Des-ionized water


13/24

O bservations

Why is necessary to remove the binder?Beca u se the binder isn't a raw material, is an imp u rity tothe process.

Why are the anodes treated with care after washing?Beca u se the anodes are extremely fragile after washing.


14/24

Drying ovenPu rpose

Remove the moist u re of the anodes from WASH DE-LUBE

Why is it important to remove moist u re from the anodes?

Beca u se water has oxygen and it wo u ld be extremely

dangero u s by temperat u res inside the sinter, co u ld bein flames.


15/24

Description

This process bring to the anodes 120C of temperat u redu ring six and half ho u rs if we u se static oven and 3

hou

rs and 15 minu

tes if weu

se vacuu

m oven.


16/24

The stearic acid has carbon in his internal composition,this is why it sho u ld make evidence of carbon to

determine if the levels are in the range of permissible.This test shows u s the effectiveness of o u r wash.

Drying oven AQL


17/24

S IN TER

Pu rposesCreate a micro str u ctu re sponge inside the anode.

P rovide a thin oxide s u rface to anodes to protect

against the environment.

Machinery req u iredLinear Sinter ( P yramid Engineer, Centorr)


18/24

O bservations

Inside the sinter they a are transported by a metal bandmade of T u ngsten that enters the oven that hastemperat u res ranging between 1600C and 2100C.


19/24

Why the sinter need a vac uu m chamber?to remove all the oxygen from the anodes

What is the f u nction of the Argon gas inside theLinear Sinter?create an inert atmosphere inside the f u rnace, and moveimp u rities before the sinter.

P revent flames b u rn in the anodes by the high

temperat u re.


20/24

Why is critical the temperatu

re in the sintering?Beca u se a very high temperat u re shrink too the anodeand lose CV

A low-temperat u re will give me Weak sinter- necks anddoes not hold high-voltage

Why is important the passivation?

Beca u se it provides a layer of oxide that protects theanodes of an u ncontrolled oxidation


21/24

SINTER AQL

Review anode dimensions( for

determinate the Sinter density)

O xygen test for Sinter effectiveness.

Wetscan to determine CV .


22/24

ANO DO S LO AD

Pu rposesWeld anodes to a stainless steel strip.

Machinery req u iredHIMECHAWALDENBURGER


23/24

O BSERVATI O NS


24/24

Anodos Load AQL

To end the process of anode load, it is necessary to

pass welding test, which consists of an anode bend 90degrees and ret u rn to its original position.

Verification of height and spacing of anodes, this testis done by meas u ring the distance between anode andsteel strip, this test is vital for the following processes,since these meas u res depend on the proper handlingthe anode.

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