Superplastic Forming/Diffusion Bonding Technology for Hollow Double Layer Structure of TA15 Titanium Alloy With Local Weight Reduction
PENG Peng1, LIU Taiying2, JIANG Shaosong1, 3, HOU Chenrui4, ZHANG Jinyuan1, LI Yang1,YANG Shang1, HAN Cong1, LU Zhen1
1. State Key Laboratory of Metal Precision Hot Processing, Harbin Institute of Technology, Harbin 150001, China;
2. Beijing Xinghang Electro-Mechnical Equipment Co., Ltd., Beijing 100074, China;
3. Harbin Hangyu Jingchuang Technology Co., Ltd., Harbin 150010, China;
4. Aviation Key Laboratory of Science and Technology on Advanced Titanium Alloys,
AECC Beijing Institute of Aeronautical Materials, Beijing 100095, China
High-temperature tensile tests were performed on TA15 titanium alloy at strain rates of 0.001 s–1, 0.005 s–1, 0.01 s–1 and temperatures of 880 ℃, 900 ℃, 920 ℃, 940 ℃. The material exhibits excellent superplasticity with elongation exceeding 500% above 920 ℃ and below 0.005 s–1. The constitutive equations of TA15 titanium alloy and the strain sensitivity index m and material constant K values at different temperatures with strain rate of 0.005 s–1 were calculated. Finite element simulations were used to analyze the thickness distribution of the double-layered structural component, and pressure–time curves were obtained. At the temperature of 920 ℃, the hollow double layer structural parts with local weight reduction are made by using pre-hollow panels SPF/DB, the minimum wall thickness is 0.31 mm, the diffusion area of the component was analyzed by ultrasonic C-scan, and the results showed that the bonding ratio is higher than 95%.