Surface Reforming of Ti Wire by Dipping Heating of Ti Wire into Pure Ni, Ni/Ti, Ni/Al Mixed Powders

Abstract

The surface reforming of Ti wire by powder metallurgy was investigated in this study. Pure Ni powder, Ni/Ti powder and Ni/Al powder were used as coating materials. A piece of Ti wire (φ=1.0 mm) was placed in an alumina crucible, and coating materials (Ni powder, Ni/Ti premixed powder, Ni/Al premixed powder) were filled around the Ti wire. The alumina crucible was vacuum sealed in a quartz tube with 2 ×10^-3 Pa. The quartz tube was heated in an electric furnace for 60 min. For the test piece obtained, microstructure, phase and Vickers hardness were measured. A uniform compound layer was formed when the Ni / Al premixed powder was used as the coating material. The intermetallic compound layer was consisted of (Ti₃Al+NiTi), (Ti₃Al+Ti₂Ni+τ₄) phases. The surface reforming of Ti wire was able to be performed by dipping heat of Ti wire into Ni/Al premixed powder.