TC11钛合金盘不同显微组织的疲劳-蠕变特性

 3种显微组织的TC11合金盘疲劳-蠕变交互作用试验的结果表明,循环应力σ_(max)在560～660MPa范围内,双态组织具有最好的疲劳-蠕变性能,网篮组织次之,等轴组织最差;其它应力范围,网篮组织寿命远高于等轴组织,也高于双态组织。SEM观察发现,3种组织裂纹源区和扩展早期均具有明显的解理特征,且解理平面的形成与裂尖塑性应变累积和高温氧化效应有关。随着裂纹扩展,解理迹象逐减,疲劳条纹和蠕变空洞骤增,交互作用明显增强。

FATIGUE-CREEP BEHAVIOUR OF VARIOUS MICROSTRUCTURE IN TCll TITANIUM ALLOY DISCS

The fatigue-creep behaviour of three microstructures in TC11 alloy discs is studied, the results show that when cycle stressσmax is ranged from 560~660 MPa, the bimodel is associated with the best fatigue-creep behaviour, the basket-weaver, the better and the equiaxed the worst. In other stress range, the life of the basket-weaner is far longer than that of the equiaxed and longer than that of the bimodel also. By SEM observation it is found that cleavage fracture is obvious on the source of fracture and at the beginning of propagation; furthermore, the forming of these facets is related to plastic strain accumulation at crack-tip and oxidation at high temperature; with cracking, cleavage facets decrease gradully, while fatigue striations and creep holes rapidly increase hence fatigue-creep interaction enhance obviously.