中國有色金屬學(xué)報(bào)(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 29 No. 5 May 2019 |
（1. National-Local Joint Engineering Laboratory of Intelligent Manufacturing Oriented Automobile Die and Mould, Tianjin University of Technology and Education, Tianjin 300222, China;
2. State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China）
Abstract:The microstructural evolution, mechanical properties and fracture mechanism of a Ti-5Al-5Mo-5V-3Cr-1Zr (Ti-55531) alloy after solution (760-820 °C) plus aging (580-640 °C) treatments were investigated. The results show that the volume fraction of the primary α (αp) phase decreases with the increase of solution temperature, and the length of the secondary α phase (αs) decreases while its width increases with the increase of aging temperature. Yield and tensile strengths decrease with the increase of solution temperature, while increase with the increase of aging temperature. A good balance of tensile strength and ductility of the alloy is obtained under solution of 800 °C for 2 h plus aging of 640 °C for 8 h, in which the tensile strength is 1434 MPa and the elongation is 7.7%. The coarsening αs phase makes crack propagation paths deflected and tortuous, which increases the crack propagation resistance and improves the ductility and fracture toughness.
Key words: Ti-5Al-5Mo-5V-3Cr-1Zr titanium alloy; hot treatment; solution; aging; microstructural evolution; mechanical properties; fracture mechanism
