Research on Plasma Arc Melting-Pressure Welding Method for Nitinol Alloy Wire

摘要

According to the problem of the joint performance degradation in melting nitinol alloy wire connection, the method of melting-pressure connection applying plasma arc welding as melting heat source was designed and the special flexible fixture was invented to realize the welding process. the Φ2 mm nitinol alloy wire connected by this method is shaped well. The characteristic of the welded joint microcosmic formation shows that the grains appear rheological pattern in heat-affected zone. The tensile strength of the joint by plasma arc melting-pressure welding after annealing is 89% of the base metal, it also increases by 43% comparing with the plasma fusion welding joint. The shape memory of the joint is about 97.1% of the base metal, which is higher than the fusion weld joints by 3.3%.