Influence of Silver Addition on Structure, Martensite Transformations and Mechanical Properties of TiNi–Ag Alloy Wires for Biomedical Application
Gulsharat Baigonakova, Екатерина Марченко, Timofey Chekalkin, Ji-hoon Kang, Sabine Weiß, Aleksei Obrosov
Abstract
The microstructural and functional behavior of TiNi-based wires with a silver content of 0-1.5 at.% was evaluated. The concentration range for Ag doping determined for the TiNi wires with potential for the medical industry was 0-0.2 at.%. Microstructure analysis of TiNi wires with different silver contents at room temperature indicated a multiphase structural state. Various internal structures with tangled grain boundaries were formed by intense plastic deformation. The nanocrystalline structure and phase state of wire with the minimum silver content (0.1 at.% Ag) provide full shape recovery, the greatest reversible strain, and optimal strength and ductility. TiNi ingots with a high Ag content (0.5-1.5 at.%) cracked under minimum load due to excess silver that crystallized along the grain boundaries and broke cohesion bonds between the TiNi grains.