Metallic fasteners e.g. screws and rivets - made at least partially of memory alloy in areas which are deformed during fastening

摘要

Metallic fasteners such as screws, rivots, clamps, washers etc. are made of memory alloy material at least in the areas which are subjected to diformation during the fastening stage. The memory alloy is a Ni-Ti-based alloy, an Fe-based alloy; Cu-based alloy or a Ni-Ti-Cu-based alloy. After assembling and tightening the fastener in its martensitic structure, the assembly is heated to convert into an austenitic structure which returns the fastener to its original shape. ADVANTAGE - Parts can be more safely held together as the memory alloy prestresses the fastener as it regains its initial dimensions.