Ti-1023合金自β相区慢冷过程中的显微组织演变及力学性能  

Microstructure evolution and mechanical properties of Ti-1023 alloy during β slow cooling process

作　　者：明惠 朱程鹏 宋雪雁 张晓泳[1] 周科朝[1] Hui MING;Cheng-peng ZHU;Xue-yan SONG;Xiao-yong ZHANG;Ke-chao ZHOU(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第12期3685-3698,共14页中国有色金属学报（英文版）

基　　金：the financial supports from the National Natural Science Foundation of China(No.51871242);the Innovative Province Construction Special Project of Hunan,China(No.2020GK4018);the Technology Research Project of Hunan Province,China(No.2021GK1080)。

摘　　要：系统研究Ti-1023合金在以1℃/min的冷却速度从单相区冷却到两相区的过程中的显微组织演变和力学性能。随着最终冷却温度的降低,在β基体上依次析出晶界α’马氏体(α’_(GB))、晶界α相(α_(GB))、魏氏体晶界α相(α_(WGB))和魏氏体晶内α相(α_(WI))。相应地,Ti-1023合金的力学性能和变形机制也发生了显著变化。当最终冷却温度高于700℃时,拉伸曲线出现明显的双屈服现象,并且伸长率大于20%。而最终冷却温度低于700℃时,双屈服现象消失。这主要是由于随着α(α’)析出相的增加,Ti-1023合金的β稳定性增强,其室温变形机制逐渐从应力诱导的α"马氏体相变转变为位错滑移。此外,结合晶粒尺寸和析出相效应,分析Ti-1023合金的强化机制。Microstructure evolution and mechanical properties of Ti-1023 alloy during cooling from single-phase region to dual-phase region with the cooling rate of 1℃/min were systematically investigated.As the final cooling temperature decreased,grain boundary α'martensite(α'_(GB)),grain boundaryαphase(α_(GB)),Widmanstatten grain boundaryαphase(α_(WGB)),and Widmanstatten intragranularαphase(α_(WI))were sequentially precipitated.Correspondingly,mechanical properties and deformation mechanisms of Ti-1023 alloy changed significantly.When the final cooling temperature was higher than 700℃,tensile curve showed an obvious double-yielding phenomenon with elongation>20%.Whereas the final cooling temperature was lower than 700℃,and the double-yielding phenomenon disappeared.This was mainly attributed to the fact that β stability of Ti-1023 alloys was enhanced with the increase ofα(α')precipitated phases.And the room temperature deformation mechanism gradually changed from stress-induced α"martensitic phase transformation to dislocation slip.Furthermore,strengthening mechanism of Ti-1023 alloy was analyzed in combination with grain size and precipitated phase effects.

关 键 词：TI-1023合金 显微组织演变 晶界α’马氏体 热处理 

分 类 号：TG146.23[一般工业技术—材料科学与工程]