Effect of Heat Treatment on Fracture Toughness Properties of TC4-DT Alloy
Ti-6A1-4V titanium alloy is a key structure and rotatable parts material for aerospace craft. The heat treatment of domestic Ti-6A1-4V products is generally full annealing. This article studies TC4-DT alloy sheets by solution treatment in β area,α-β area and followed ageing,considering different solution temperatures,ageing temperatures,ageing time and cooling rate on fracture toughness properties. It is found that TC4-DT alloy sheets treated by β area solution treatment and followed ageing appear superior fracture toughness properties comparing to α-β area solution treatment, owing to the bulky reticular widmanstatten structure at prior β grain boundaries. Correspondingly, more α-β grain boundaries form. Both Platelet α in widmanstatten structure and at grain boundaries increases the resistance of dislocation glides and crack extension. As a result, β area solution-treated sheets have better fracture toughness properties. Fracture surface observation shows that the pathway of crack growth in TC4-DT alloy sheets treated by α-β area solution treatment with bimodal structure is relatively flat, and there are only a few short secondary cracks. On the contrary, the pathway of crack growth in β area solution-treated alloy sheets is flexuous,and there are many rough and severe secondary cracks. As the secondary cracks extension,more branches forms, which absorb more energies,and fracture is resultantly postponed.
TCA-DT alloy fracture toughness property solution ageing
Hongchuan Ye Xuehua Zhang Henglei Qu Hui Li Fuguo Li
Western Titanium Technologies Co. ,Ltd. Xian,China, 710201 Western Metal Materials Co. ,Ltd. Xian,China, 710201 Northwestern Polytechnical University. Xian,China, 710012
国际会议
The 12th World Conference Titanium(第十二届世界钛会 Ti-2011)
北京
英文
1104-1106
2011-06-19(万方平台首次上网日期,不代表论文的发表时间)