Overview of the Machining of Titanium Alloys

Machining of titanium alloys has always attracted considerable great interest in the manufacturing sector as well as within the scientific research community worldwide. Titanium alloys are widely employed in aero-engine and for airframe manufacture because of their outstanding strength to density ratios relative to other materials. Due to the expensive cost of titanium alloys, relative to other metals, attributed mainly to the complexity of the extraction process, difficulty of melting and problems during fabrication and machining, integrated researches have been established globally to improve their machinability. Success in the machining of titanium alloys can be achieved by employing the correct selection of cutting tools, cutting environment, and appropriate cutting conditions for each machining operation. This article reviews the machining of titanium alloys, highlighting the main cutting tools, cutting parameters, and cooling environments that have been employed in last three decades. The purpose is to enhance the general understanding of practitioners and researchers on the principles of machining titanium alloys, the properties that impair their machinability, performance of different cutting tools, wear mechanisms, and dominant failure modes of cutting tools under different machining conditions, including various techniques that enhance the machining of titanium alloys. A good understanding of these parameters as well as processing time and functionality of the machined component will lead to efficient and economic machining of titanium-base superalloys.