FRICTION WELDING

ANWAR SADATH M AROLL NO : 4

S1 MTECH PE

CONTENTSINTRODUCTIONBENEFITSWELDING TECHNIQUES

SPIN WELDING LINEAR WELDING FRICTION SURFACING FRICTION STIR WELDING

CONCLUSIONREFERENCES

INTRODUCTION Friction welding (FW) is a class of solid-state joining processes

Generates heat through mechanical friction between a moving work piece and a stationary component, with the addition of a lateral force called "thrust load" to plastically displace and fuse the materials.

When sufficient energy input has occurred (length loss), the rotation is stopped and thrust load increased, to forge the parts together and form a solid state bond.

Friction welding is used with metals and thermoplastics in a wide variety of aviation and automotive applications

WELDING TECHNIQUES

SPIN WELDING

LINEAR WELDING

FRICTION SURFACING

FRICTION STIR WELDING

SPIN WELDINGSpin Welding uses rotational motion and high axial pressures

(thrust load) to convert rotational energy into frictional heat at a circular interface.

The heat produced by this rubbing action raises the inter-surface temperature of the two parts to the plastic state where the high thrust load extrudes metal from the weld region to form an upset.

When sufficient energy input has occurred (length loss), the rotation is stopped and thrust load increased, to forge the parts together and form a solid state bond.

Rotary friction welding is very energy efficient compared to most competitive welding processes

SPIN WELDING

LINEAR WELDINGLinear friction welding (LFW) is similar to spin welding

except that the moving chuck oscillates laterally instead of spinning.

The speeds are much lower in general, which requires the pieces to be kept under pressure at all times.

This also requires the parts to have a high shear strength.

Linear friction welding requires more complex machinery than spin welding, but has the advantage that parts of any shape can be joined, as opposed to parts with a circular meeting point.

LINEAR WELDING

LINEAR WELDING

FRICTION SURFACING

Friction surfacing is a process derived from friction welding where a coating material is applied to a substrate. A rod composed of the coating material (called a mechtrode) is rotated under pressure, generating a plasticised layer in the rod at the interface with the substrate. By moving a substrate across the face of the rotating rod a plasticised layer is deposited between 0.2–2.5 millimetres (0.0079–0.098 in) thick depending on mechtrode diameter and coating material.

FRICTION STIR WELDINGA constantly rotated cylindrical-shouldered tool with a profiled nib is

transversely fed at a constant rate into a butt joint between two clamped pieces of material.

The nib is slightly shorter than the weld depth required, with the tool shoulder riding atop the work surface.

Frictional heat is generated between the wear-resistant welding components and the work pieces. This heat, along with that generated by the mechanical mixing process and the adiabatic heat within the material, cause the stirred materials to soften without melting.

As the pin is moved forward, a special profile on its leading face forces plasticised material to the rear where clamping force assists in a forged consolidation of the weld.

FRICTION STIR WELDING

FRICTION STIR WELDING

ADVANTAGESThe combination of fast joining times, and direct heat input at

the weld interface, yields relatively small heat-affected zones.

Friction welding techniques are generally melt-free, which avoids grain growth in engineered materials.

Clean weld surface.

• Allows dissimilar materials to be joined.

• Friction welding can be used with thermoplastics.

• Friction welds often cost less

CONCLUSIONAn alternative to fusion welding

Immensely high potential in the field of thermo mechanical processing of various alloys

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