摘要
The effects of solution treatment(ST)and cold rolling(CR)on structure and tensile properties of a heavily hot-rolled(HR)Ti–7.5Mo alloy were investigated.Experimental results indicated that,after HR with a one-pass 65%reduction in thickness,the pores in as-received samples substantially disappeared,the misorientation angle distribution became broader,and grain texture shifted toward<10-10>.Post-HR ST produced an orthorhombicα''-phase with fine needle-type morphology and caused misorientation to narrow down to 55°–65°with substantially random texture;post-ST CR caused misorientation shift toward high-angle side and texture toward<10-10>and<2-1-10>.With an increase in reduction in thickness,α'(102)intensity increased at the expense of two adjacent(112)/(022)α''-peaks.All X-ray diffraction,metallography and electron backscattered diffraction on scanning electron microscope results indicated that pre-ST HR did not affect the formation of the desired low-modulusα''-phase when the alloy was subsequently solution-treated.From a practical point of view,the most optimal tensile properties may be found in the sample solution-treated at 900°C for 30 min and cold-rolled by a 20%reduction in thickness,which demonstrated a yield strength of 924 MPa,an ultimate tensile strength of 933 MPa,a tensile modulus of 73 GPa,and an elongation of 26%.
