EXPERIMENTAL STUDIES ON CHEMICAL REACTIVITY AND DIMENSIONAL GROWTH IN MACHINING OF TITANIUM ALLOYS

Abstract

Machining of aero-gas turbine components made of titanium alloys, using different combination of tools, cutting fluids and machining parameters revealed two important characteristics namely, chemical reactivity and dimensional growth. The former is pronounced when machined with carbide tools using Sulphur based cutting oils. The reactivity was not noticeable when machined either with CBN or ceremet tools, contrary to the reports in the literature. This mechanism of chemical reaction has been studied including the development of microcracks at 400 ° F. The other phenomenon of dimensional growth is also anlysed in detail and machining parameters to reduce this growth are arrived at. The heat treatment is also envisaged to help in depriving of this detrimental dimensional growth by relieving the machining stresses. Also the scope for further research in this area is clearly defined.