Abstract
In this study we have tried to produce TiNi intermetallic compound spray coating on aluminium substrate using a composite wire of titanium wire (φ300μm) and nickel wire (φ300μm). The composite wire was melted by using CO2 laser in an atmosphere of argon gas and atomized and coated on the aluminium substrate by a high pressure argon gas. Effects of spray conditions on porosity of coating layer were investigated. Wear resistance of the coating was also evaluated by using an Ohgoshi wear tester.
It was possible to produce TiNi intermetallic compound layer using a composite wire by a laser reactive spraying method. 100% TiNi intermetallic compound was found from the X-ray diffraction analysis of coating layer. As the spray distance increased from 50 mm to 200 mm and the atomize gas pressure decreased from 392 kPa to 196 kPa, the porosity of coating layer decreaced. A porosity of 5% was obtained at the spray distance of 200 mm and the atomize gas pressure of 196 kPa. The wear resistance of the coating increased by about ten times than that of aluminiun substrate.
