In-situ synthesis Ni-Ti alloy by laser cladding

Abstract

The NiTi alloy shape memory effect can have a much larger field of application in industry and everyday life than it is now. The high cost of obtaining this material and the laboriousness of the process limit its scope of application. The use of modern 3D technology may help solve this problem This paper explores the possibility of growing samples of simple geometric shapes in the form of tubes from Ni and Ti elemental powders. Samples from 3 types of powder mixtures have been produced. The first mixture with an excess of Ni relative to the equatorial ratio, the second with a deficit of Ni, the third with 5 % addition of Cu. The microstructure of samples before and after thermal treatment in argon at 900 ̊C was studied. The heat treatment contributed the process of homogenization of the solid solution, but had no significant effect on the sample hardness or reduction of secondary phases. Heat treatment changed hardness by an average of 10%. Phase analysis before and after the heat treatment showed a significant proportion of NiTi phase as well as secondary phases of NiTi2, Ni3Ti, TiO2.