论文部分内容阅读
通过温控精度达到0.5℃/s的高精度快速相变仪研究了固溶温度和冷却速率对BT25钛合金显微组织的影响规律。结果表明:BT25钛合金的显微组织中等轴α相数量随固溶温度的升高而减少,同时β晶粒逐渐长大,组织形态从等轴组织过渡到双态组织,当固溶温度超过β相变点时组织从双态组织演变为魏氏组织;随着冷却速率的升高,显微组织中的α片层厚度逐渐降低,当冷却速率大于10℃/s时,可以抑制晶界α相的产生;在低冷却速率时的大晶粒尺寸的片层组织的断裂方式为延性韧窝断裂和解理断裂混合,当冷速提升后,断裂方式为韧性断裂。
The influence of solution temperature and cooling rate on the microstructure of BT25 titanium alloy was studied by means of a high-precision rapid phase change instrument with a temperature control accuracy of 0.5 ℃ / s. The results show that the number of α-phase in the BT25 titanium alloy decreases with the increase of solution temperature, and the β-grains grow up gradually. The microstructure of the BT25 titanium alloy transforms from the equiaxed structure to the bimodal structure. When the solution temperature exceeds β phase transition point, the microstructure evolves from the bimodal microstructure to Westend tissue. With the increase of the cooling rate, the thickness of α sheet in the microstructure decreases gradually. When the cooling rate is more than 10 ℃ / s, the grain boundary α phase. The fracture mode of large grain size lamellae at low cooling rate is ductile dimple fracture and cleavage fracture mixing. When the cooling rate increases, the fracture mode is ductile fracture.