Fixtures

We expect severe dimensional changes in welding aluminum base alloys. This can be twice as great as in the welding of steel. These parameters do influence the design of fixtures. It is a fact that coefficient of expansion of aluminum is twice that of steel and melting point is about half that of steel. But the rate of expansion is inversely proportional to the speed of welding. To reduce distortion, rigid clamping can be employed. This may induce residual stress even comparable to yield strength of the base metal resulting in cracking. Hold-down fingers design will help to tackle these problems.