Comparison Of Peening Effect Between Additive Manufacutred And Drawing Titanium Alloy

Although additively manufactured (AM) metals are attractive materials, their remarkable weak fatigue properties are an obstacle to their practical application. Thus, post-processing to improve their fatigue properties is required. In the present study, powder bed fusion using laser sintering titanium alloy, i.e., PBF-LS/Ti6Al4V was treated by shot peening (SP), submerged laser peening (SLP), cavitation peening (CP), and fine particle bombarding (FPB), then the fatigue properties were investigated by a torsional fatigue test, comparing with drawing Ti6Al4V. It was revealed that the fatigue strength at 10^7 was 446 ± 5 MPa for PBF-LS/Ti6Al4V treated by FPB+CP, 359 ± 9 MPa for LS/Ti6Al4V treated by SLP and 457 ± 22 MPa for drawing Ti6Al4V treated by SLP, whereas it was 210 ± 10 MPa for as-built (AB) PBF-LS/Ti6Al4V and 346 ± 26 MPa for non-peened drawing Ti6Al4V. Namely, the fatigue strength of PBF-LS/Ti6Al4V treated by FPB+CP exceeded that of non-peened (NP) drawing Ti6Al4V.