冷却方式对半固态Ti14合金微观组织的影响  

Influence of Cooling Models on Microstructure of Semi-Solid Ti14 Alloy

作　　者：王慧[1,2] 陈永楠[1] 高一帆[3] 魏建锋[1] 赵永庆[2] 屈可朋[1] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049 [2]西北有色金属研究院,陕西西安710016 [3]华东理工大学,上海200237

出　　处：《稀有金属材料与工程》2010年第3期447-451,共5页Rare Metal Materials and Engineering

基　　金：重大基础研究前期研究专项项目(2005CCA06400);国家“973”项目(2007CB613807)

摘　　要：采用OM,SEM,XRD研究不同的冷却方式炉冷(Furnace Cooling,FC)、空冷(Air Cooling,AC)和水淬(Water Quenching,WQ)对半固态Ti14合金微观组织形貌以及相组成的影响。结果表明:3种冷却方式均没有改变合金的相组成,但影响Ti2Cu相的形态和分布。炉冷后,Ti2Cu相以颗粒状按一定位向析出,并排列形成条状和树枝状;空冷后,Ti2Cu相以颗粒状和层片状分布于晶内和晶界;水淬后,晶界液相特征明显,晶内和晶界无明显析出。分析认为:半固态Ti14合金冷却过程中经历了包晶凝固,包晶反应发生在液相/β/Ti2Cu三线交点处,使得三线交点处的溶质分布很不规则,包晶相的形核和生长形态发生改变,同时,冷却方式不同影响包晶反应程度,从而影响后序的共析组织,使得不同冷却方式冷却后产生了不同的组织形貌。The microstructure and phase composition of semi-solid Ti14 alloy （α-Ti＋Ti2Cu） with different cooling modes （furnace cooling--FC, air cooling--AC and water quenching--WQ） were investigated by OM, SEM and XRD. The results show that the three cooling modes have no effects on the phase composition of Til4, but influence the morphology and distribution of Ti2Cu. The microstructure of Ti14 after furnace cooling consisted of granular Ti2Cu precipitates, which distributed in a certain direction presenting strip and dentritic structure. After air cooling, Ti2Cu precipitates were granular or lamellar in the grains and grain boundaries; while after water quenching, the microstructure was composed of coarse grain boundary, and no evident precipitates were observed. The semi-solid Ti14 alloy undergoes peritectic solidification during cooling process. The peritectic reaction occurs in the liquid/β/Ti2Cu trijunctions region, which makes the solute distribution there irregular, and the trijunctions dynamics quite complicated. Meanwhile the cooling modes also influence the peritectic reaction extent, and thus affect the following eutectoid, resulting in different microstructure with different cooling modes.

关 键 词：Ti14钛合金 冷却方式 微观组织 包晶反应 

分 类 号：TG146.23[一般工业技术—材料科学与工程]