Surface modification of titanium alloy using a novel elastic abrasive jet machining method

Surface modification is always employed to enhance surface integrity, where abrasive jet machining (AJM) represents a large portion. This paper investigates the impact of a new elastic abrasive jet machining (EAJM) method on the surface characteristics of Ti6Al4V alloy. A self-developed multi-element polymer microbead covered by diamond powders is employed as the abrasive with a hardness of approximately 50-80 HV. This study systematically examines and compares the performance of elastic and hard abrasives in surface modification of Ti6Al4V by AJM, investigating the effects of nozzle pressure (P) and traverse speed (v) on surface integrity. The lowest surface roughness and highest microhardness are achieved by EAJM under the condition of P = 350 kPa and v = 0.75 mm/s. Hard abrasive jet machining (HAJM) tends to produce poor surface quality when excessive parameters are applied, while the performance of EAJM is relatively stable. The most compressive residual stresses obtained by EAJM and HAJM are-300 and-140 MPa, respectively. EAJM is able to modify the surface characteristics and produce a better surface quality with a lower material removal amount compared to HAJM. In addition, the relatively lower crushing rate of the elastic matrix and the fact that the material removal capability of EAJM relies on the diamond powders on the abrasive surface make it easier for EAJM to maintain its performance.