Influence of thermal cycling on weldments of non-ferrous materials : I - Aluminium Alloy 6061

SINCE the study of "thermal" fatigue on materials is generally concerned with repeated heating and cooling of the alloy under mechanical constraint, very little is known about the effect of thermal cycling of unrestrained materials. The materials studied to-date subjected to such "thermal", or "thermomechanical" fatigue' do not include studies of precipitation hardenable alloys.' Although, recently some work has been undertaken on the thermal cycling of a duraluminium type material,3 almost nothing is known about the effect of thermal cycling on weldments of 6061 aluminium alloy. Such studies will help in obtaining the design data concerning metallic shield to protect the main satellite structure made of plastics from
radiation damage in space as well as from other relevant
hazards when such scientific satellites are exposed once to the sunlit side and subsequently to very low temp-erature in the dark side during orbiting around the earth and are, consequently, subjected to thermal fatigue. The present study has been undertaken in order to find the effect of thermal cycling on mechanical properties of welded 6061 aluminium alloy.