NiTi Coatings Produced by Plasma Transferred Arc Welding Process and Its Wear Characteristics.

In this work, a feasibility study has been conducted to produce NiTi intermetallic compound layer using mixed powders of Ni and Ti by plasma transferred arc welding. Wear characteristics of the coatings were evaluated by using a modified Okoshi-type wear tester.It was possible to produce intermetallic compound coatings from the simply mixed powders by plasma transferred arc welding. Hardness value reached up to 800 HV in deposited metal. The coating was identified as NiTi, TiFe and TiFe2 intermetallic compounds by an X-ray diffraction analysis. The wear resistance of the coatings was equivalent to that of Stellite No.6 coatings. The coatings show excellent wear characteristics under the condition of lower friction speed. The wear progress of the coatings reveal no sever wear regime and constant, low rate of wear.