固溶和时效对Ti_(2)041合金组织与硬度的影响

Effects of Solution and Aging Treatment on Microstructure and Hardness of Ti_(2)041 Alloy

研究了不同温度的固溶和时效工艺对Ti_(2)041合金组织和硬度的影响。结果表明:当固溶温度为700℃时,随着保温时间增加,组织中初生α相(αp)的含量逐渐增多,晶粒尺寸逐渐增大;当固溶温度为750℃时,随保温时间增加,发生了静态再结晶,且有次生α相(αs)析出,晶粒尺寸也逐渐增大;当固溶温度为800℃时,晶粒内部出现α′马氏体,形貌由等轴状变为板条状。在不同固溶温度下硬度值变化也不同,当固溶温度为700℃时,随着保温时间的增加,硬度(HV)值从3016 MPa降到2852 MPa;在固溶温度为750℃时,硬度值随着保温时间的增加先升高后降低,最大值为3082 MPa;在固溶温度为800℃时,硬度值随着保温时间的增加逐渐增大,最大值为3314 MPa。在经时效处理后,不同时效温度下均出现了次生αs相。随时效温度的升高,次生αs相尺寸越小,显微硬度值逐渐增大,最大值达到4517.5 MPa,主要强化机制为第二相(次生αs相)弥散强化。

The effects of solution and aging at different temperatures on the microstructure and hardness of Ti_(2)041 alloy were studied. The results show that at the solution temperature of 700 ℃, the content of primary α phase and the grain size increase gradually with the increase of holding time. At the solution temperature of 750 ℃, with the increase of holding time, it can be seen that there are secondary α phases in the microstructure and static recrystallization occurs. The grain size increases gradually. At the solution temperature of 800 ℃, α′ martensite appears in the microstructure, and the morphology changes from equiaxed to lath. The change of hardness value is also different under different solution temperatures. At the solution temperature of 700 ℃, with the increase of holding time, the hardness value decreases from 3016 to 2852 MPa. At the solution temperature of 750 ℃, with the increase of holding time, the hardness value increases first and then decreases. The maximum value is 3082 MPa. At the solution temperature of 800 ℃, with the increase of holding time, the hardness value increases gradually and the maximum value is 3314 MPa. After aging treatment, secondary α phase appears in the microstructure at different aging temperatures. With the increase of aging temperature, the size of secondary α phase decreases. The hardness value increases gradually and the maximum value is 4517.5 MPa. The main strengthening mechanism is the second phase(secondary α phase) dispersion strengthening.