(西北有色金属研究院，西安 710016)
摘 要: 通过对TC21合金进行近β锻，获得典型的双态组织。通过X射线衍射(XRD)、光学显微镜(OM)和扫描电镜(SEM)分析了固溶处理对双态TC21合金组织的影响。XRD分析表明：随着固溶温度的降低，TC21合金固溶水冷处理后的亚稳定相组成依次为α″(≥Tβ)、α+α″(Tβ≈935 ℃)、α+α″+β(915、855 ℃)、α+β(≤835 ℃)。分别对TC21合金进行895 ℃, 2 h，AC、QFC(慢炉冷)、FC+(610 ℃, 4 h，AC)热处理，研究固溶冷却速率对合金组织性能的影响。结果表明：随着冷却速率的增加，等轴α相基本保持不变，次生α相含量减少，合金强度增加，塑性减小。此外，分别对TC21合金在915、905、895、870和835 ℃进行2 h, AC固溶处理，金相分析表明：随着固溶温度的降低，等轴α相相含量及尺寸基本保持不变，次生α条所占比例增加，α条变宽。
关键字: TC21合金；冷却速率；近β锻；双态组织
morphology of near β forged TC21 alloy
（Northwest Institute for Norferrous Metal Research, Xi’an 710016, China）
Abstract:Two-state microstructure of TC21 alloy was obtained by near β forging process. The effect of different solution treatments on the microstructure of TC21 alloy was analyzed by X-ray diffractometry (XRD), optical microscopy (OM) and electron microscopy (SEM). The XRD analysis reveals that with the decrease of solution treatment temperature, the phase compositions of TC21 alloy are α″ (≥Tβ), α+α″(Tβ≈935 ℃), α+α″+β (915, 855 ℃), α+β (≤835 ℃). The morphology and mechanical properties of TC21 alloy solution treated at 895 ℃ for 2 h with different solution cooling rate (air cooling, quick furnace cooling, furnace cooling) and then aged by 610 ℃, 4 h, AC was analyzed. As a result, with the increase of solution cooling rate, there is no obvious change on the primary equiaxed α phase, the content of secondary α phase decreases, the strength of the alloy increases, and the plasticity decreases at the same time. TC21 alloy was solution treated at 915, 905, 895, 870 and 835 ℃ for 2 h followed by air cooling, respectively. With the decrease of solution treatment temperature, the width and content of lamellar α phase increase, and there is no difference between the equiaxed α phase of TC21 alloy solution treated at different temperatures.
Key words: TC21 alloy; cooling rate; near β forging; two-state microstructure
