Ni3Ta High Temperature Shape Memory Alloys: Effect of B Addition on the Martensitic Transformation and Microstructure

Shape memory alloys operating at high transformation temperatures are considered very attractive materials for enabling a new class of high temperature smart devices for different fields, such as automotive, aerospace and appliances.In this work, the effect of B addition in the Ni3Ta alloy was studied; B contents from 1 to 5 (at.%) were alloyed in the place of Ta. For the all studied compositions, the calorimetric investigations have shown martensitic transformation above 220°C, which was stable during thermal cycling. The characteristic phases of Ni3Ta alloyed with B were identified using both scanning electronic microscopy and powder X-ray diffraction analyses.