Scanning Speed Influence on the Microstructure and Micro hardness Properties of Titanium Alloy Produced by Laser Metal Deposition Process

Abstract

Ti6Al4V is an important automobile and aerospace alloy because of its excellent properties, but it is challenging to process this material through the conventional manufacturing processes. Laser metal deposition process which is an additive manufacturing technologies an alternative manufacturing process that offers lots of advantages for processing difficult to manufacture materials like titanium and its alloys. Laser metal deposition process has the ability to improve the properties of materials and also improve the fuel efficiency of moving parts by making them lighter and hence help to reduce the carbon foot printing in the transportation industry. Laser metal deposition process (LMD) is fairly new and some of the process physics still needs to be understood. In this study, the effect of scanning speed on the resulting metallurgical and mechanical properties of Ti6Al4V powder deposited using LMD was studied. Ti6Al4V powder was deposited coaxially with a 4.0 Kw Rofin Sinar Nd: YAG laser on Ti6Al4V substrate. The laser power, powder flow rate and gas flow rate were kept constant while the scanning speed was varied between 0.005 and 0.095m/sec. The microstructures of the samples were studied using the optical microscope and the micro hardness was also measured using the Vickers hardness tester. The properties of the deposited samples were studied with the varying scanning speed.The micro hardness was found to increase with the increase in the scanning speed