Variations in the surface integrity of Ti-6Al-4V by combinations of additive and subtractive manufacturing processes

Abstract

Additive manufacturing (AM) has recently been accorded considerable interest by manufacturers. Many manufacturing industries, amongst others in the aerospace sector, are already using AM parts or are investing in such manufacturing methods. Important material properties, such as microstructures, residual stress, and surface topography, can be affiected by AM processes. In addition, a subtractive manufacturing (SM) process, such as machining, is required for finishing certain parts when accurate tolerances are required. This finish machining will subsequently affiect the surface integrity and topography of the material. In this research work, we focused on the surface integrity of Ti-6Al-4V parts manufactured using three diffierent types of AM and finished using an SM step. The aim of this study was to gain an understanding on how each process affiects the resulting surface integrity of the material. It was found that each AM process affiects the materials' properties diffierently and that clear diffierences exist compared to a reference material manufactured using conventional methods. The newly generated surface was investigated after the SM step and each combination of AM/SM resulted in diffierences in surface integrity. It was found that diffierent AM processes result in diffierent microstructures which in turn affiect surface integrity after the SM process.