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研究了激光熔化沉积TC17钛合金原态及固溶时效后的显微组织,分析了一重固溶+时效和两重固溶+时效热处理对初生α相含量、长宽比的影响。结果表明,激光熔化沉积态TC17钛合金凝固组织为粗大的柱状β晶,显微组织为细密的片层α+β两相网篮组织。当固溶温度从800℃升高到835℃时,初生α相体积分数由53%减少到34%,宽0.4～0.5μm,长宽比约从9∶1减小到5∶1;时效后初生α相片层显著粗化,宽0.7～0.8μm,次生α相极其细密,均匀分布于初生α片层之间,含量随固溶温度升高逐渐增多。当进行两重固溶处理时,第一步固溶温度决定初生α相含量,而对初生α相的宽度及长宽比几乎没有影响,第二步固溶时间主要影响初生α相的长宽比,而对初生α相的含量及宽度几乎没有影响。
The microstructure of laser melted and deposited TC17 titanium alloy was studied in situ and after solution treatment. The effects of single solution and aging treatment and double solution and aging heat treatment on the content and aspect ratio of primary α phase were analyzed. The results show that the solidified microstructure of the laser-melted and deposited TC17 titanium alloy is a coarse columnar β-crystal, and the microstructure is fine-grained α + β two-phase baskets. When the solution temperature increases from 800 ℃ to 835 ℃, the volume fraction of primary α phase decreases from 53% to 34%, the width of 0.4 ~ 0.5μm and the aspect ratio decreases from 9:1 to 5:1. After aging The primary alpha layer is significantly coarser and 0.7-0.8 μm wide. The secondary α phase is extremely fine and evenly distributed between the primary alpha layers, and the content gradually increases with increasing solution temperature. When the two solid solution treatment, the first solution temperature determines the primary α-phase content, while the primary α-phase width and aspect ratio almost no effect, the second solution time mainly affect the primary α-phase length and width Ratio, while the primary α-phase content and width of almost no effect.