Isothermal precision forging of Ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy impeller with twisted blades
(1.黑龙江省哈尔滨市哈尔滨工业大学材料科学与工程学院
2.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)
2.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)
Abstract: Ti-6.5Al-3.5Mo-1.5Zr-0.3Si (TC11) alloy impeller is an important part in the airspace engine that serves under severe working conditions, and it requires excellent mechanical properties and high dimensional precision. However, the integral titanium alloy impeller is difficult to precisely forge because of its complex shape and poor formability. In order to develop optimum forging process of this kind of complex parts, the deformation characteristics of TC11 alloy under isothermal compressing conditions were studied. Furthermore, an alternative material, namely pure lead, was selected to model the forming process of the impeller and investigate metal flow during forging. Based on the research, local loading method was determined to forge the TC11 alloy impeller precisely under isothermal condition. The dimensional accuracy, mechanical properties and microscopic structure of the forged product satisfy operating requirements.
Key words: titanium alloy impeller; isothermal forging; deformation behavior; physical modeling