Strength-toughness synergic Ti-Mo double harmonic alloys prepared via powder metallurgy

Abstract

A series of double harmonic Ti-Mo alloys are prepared using a powder metallurgy method. These alloys display chemical and structural double harmonic (CSDH) heterogeneity. The Ti-10Mo CSDH alloy is composed of α″, β(s), and residual β-Mo phases. As Mo increases, β(s) and β-Mo increase but α″ decreases. EDS and SEM results prove the chemical and structural harmonic distributions. All Ti-Mo CSDH alloys exhibit excellent mechanical properties. Especially, the Ti-10Mo CSDH alloy exhibits superior strength-toughness synergy (938.7 ± 49.5 MPa for Rp0.2, 1075.5 ± 54.7 MPa for Rm, ∼10.38 % for A and 111.6 ± 6.4 MPa for UT). The double harmonic heterogeneity producing the TRIP effect and back stress during plastic deformation is the major reason for strength-toughness synergy.