A Note on the Change in the Surface Quality Characteristics during Flat Grinding of Titanium Intermetallic with Shape Memory Effect

Abstract

Ti-based intermetallic compounds are characterized by low machinability, therefore, to obtain accurate dimensions and shape of the surface grinding and Wire EDM are used. The unique properties of NiTi intermetallic alloys are largely influenced by structural phase transformations and variations in microhardness caused by processing accompanied by thermal phenomena. Having an understanding of the physics of the process, it is possible to counteract negative effects, which helps to preserve thermomechanical properties of the final NiTi products. Accumulation of knowledge about the quality of processing with various abrasive tools is part of the larger research presented in this article. Samples of titanium nickelide with a temperature Af=+25 0С were abraded with ordinary and high porosity SiC wheels. The article studied phase transformations using X-ray diffraction analysis and microhardness. The experimental data were processed using mathematical statistics. X-ray diffraction patterns and microhardness analysis showed that a significant effect on the structural transformation and corresponding increase in microhardness is exerted by grinding with green SiC wheels with normal porosity caused by an increased thermal effect on the surface. Simultaneously, the impact of Wire EDM process on microhardness in preparing workpieces for grinding was evaluated. It was established that grinding of Ti-based intermetallic compounds with memory effect should be performed by SiC wheels with an open structure of high porosity.