Kinetic Spot WeldingCurtis Prothe

DMC Clad MetalMt. Braddock, PA

EPNM 2012May 2-5 Strasbourg, France

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Kinetic Spot Welding (KSW) was developed and patented by DMC to:Provide a spot weld having the

qualities of an Explosion Weld. Create a system viable for use in

any manufacturing or fabricating environment.

Provide a means of repetitive, reliable spot welding of thin dissimiliar metals.

Dynamic Materials Dynamic Materials CorporationCorporationKSW: A new generation of welding from

and old family tree.

Kinetic spot welding is a subset of the well developed, robust Explosion Welding Technology

A flyer sheet is accelerated across a distance to collide with a fixed base sheet under conditions which cause welding

For kinetic spot welds, the explosive energy source is replaced with a highly focused, common industrial alternative

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Explosion Welding (EXW) SynopsisEXW is a well known technology for

joining dissimilar metals.EXW is a Cold Process - No bulk heating

of the metals, no diffusion, continuous melting, or HAZ

Large explosive energy requirements limit the use to remote, or isolated areas.

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EXW Spot Welds

Explosion spot welding demonstrated with reduced explosive quantities

EXW Spot welds technically successful, but still plagued by explosive licensing and regulatory issues.

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Kinetic Spot Welding (KSW)Utilizes the energy of a high velocity

projectile to generate the collision parameters necessary to create a weld.

KSW projectile can be accelerated by a deflagrating product (propellant, or gunpowder), pneumatic or hydraulic pressure, gas combustion or magnetic impulse.

Eliminates the use of explosives

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Kinetic Welding Schematic # 1

Containment Tool

Flyer Sheet

Base Sheet

Standoff Dimple

Energy Source

Kinetic Energy Transfer Tool

Confinement and Alignment Tool

Supp

ort T

ool

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Kinetic Welding Schematic # 2

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Kinetic Welding Schematic # 3

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Kinetic Welding Schematic # 4

Weld Zone

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KSW DevelopmentIn order to develop a kinetic spot

weld, the parameters necessary to develop EXW must be created.

The primary parameters to be controlled are:EnergyCollision AngleCollision Velocity

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KSW Development

The projectile must convey the proper amount of kinetic energy, requiring a balance of velocity and mass.

The projectile material must not damage the cladding metal during impact.

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KSW Development

Welding parameters were achieved by developing the proper:Projectile ShapeProjectile Material typeImpact velocities

Dynamic Materials Dynamic Materials CorporationCorporationKSW Parameters

Cladder Metal

Cladder Thickness

Base Metal

Projectile Velocity (ft/sec)

Projectile Velocity(m/sec)

Copper 102

1.6mm (0.063”)

Carbon Steel

2000 610

Tantalum 0.25mm (0.010”)

Carbon Steel

1750 530

Tantalum 0.50mm(0.020”)

Carbon Steel

2150 650

Aluminum 5052 O

1.6mm (.063”)

Aluminum 5052 O

2150 650

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Materials Welded Using KSW

1.6mm Copper welded to Carbon Steel

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Materials Welded Using KSW

Copper to Carbon Steel interface shown at 50x

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Materials Welded Using KSW

Aluminum 5052 O to Aluminum 5052 O KSW Interface

Dynamic Materials Dynamic Materials CorporationCorporationKSW Development

During EXW, standoff is achieved by using sacrificial devices in the interface

In KSW, the cladding metal is dimpled to create standoff distance without introducing foreign material in the interface

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0.5mm Tantalum bonded to Carbon Steel

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Materials Welded Using KSW

0.50 mm Tantalum welded to Carbon Steel

38mm14mm

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KSW TestingUltrasonic inspection show that projectiles

18.5mm in diameter create weld diameters from 10 to 14 mm.

Typical destructive testing techniques, such as ASME SA265 shear strength testing are not viable for such thin metals.

DMC Developed a hydrostatic testing fixture to test the strength of the KSW weld.

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KSW TestingKSW sample of 0.50mm Tantalum-

Carbon Steel hydrostatically tested.

>55 MPa was applied without weld failure or joint separation.

Bond strength of spot weld exceeded the shear strength of the tantalum.

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Tantalum Sheared under pressure - KSW intact

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Advantages of KSW Spot Welding

Provide a spot weld having the qualities of an Explosion Weld.

Can be used in a typical fabrication shop environment

Does not require the use of explosives

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Advantages of KSW Spot Welding

Best suited for very thin cladding sheets

Can be used to attach a liner inside a finished vessel

Can be used for repair of damaged cladding

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Limitations of KSW

Not a full area cladding technology. Each spot weld is limited to a size of approximately 10 to 16 mm

Not suitable for thick cladding

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Potential KSW Applications Lining vessels with thin layers of

expensive metals such as Tantalum or Niobium.

Spot welding of alloys and dissimilar metals that are difficult or impossible to weld with conventional resistance spot welding techniques

Attachment of applique spots, such as thin platinum discs onto titanium

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Summary - Kinetic Spot WeldingProvides Spot Welds with EXW qualitiesPossible to produce spot welds between

practically any metal combinationViable in any manufacturing

environmentRapid cycle time possible with

automation

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Thank You

For More Information on DMCVisit

www.dynamicmaterials.com