FRICTION WELDING AND ITS PROCESS

The frictional energy generated when two bodies slide on each other is transformed into heat ; when the rate of movement is high and the heat is contained in a narrow zone, welding occurs.

In the practical form of friction welding, one part is firmly held while the other (usually cylindrical) is rotated under simultaneous application of axial pressure. The temperature rises, partially formed welded spots are sheared , surface films are disrupted , and the rotation is suddenly arrested when the entire surface is welded. Some of the softened metal is squeezed out into a flash, but it is not fully clear whether melting takes place.

The heated zone being very thin, dissimilar metals are easily joined, for example, mild steel shanks can be fastened to high-speed-steel tool ends.

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Mechinopedia For Mechanical Engineers

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