CAJ | 학술논문

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(WaterQuenching,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Ti_2Cu相的形态和分布.炉冷后,Ti_2Cu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,Ti_2Cu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/Ti_2Cu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.
채용OM,SEM,XRD연구불동적냉각방식로랭(Furnace Cooling,FC)、공랭(Air Cooling,AC)화수쉬(WaterQuenching,WQ)대반고태Ti14합금미관조직형모이급상조성적영향.결과표명:3충냉각방식균몰유개변합금적상조성,단영향Ti_2Cu상적형태화분포.로랭후,Ti_2Cu상이과립상안일정위향석출,병배렬형성조상화수지상;공랭후,Ti_2Cu상이과립상화층편상분포우정내화정계;수쉬후,정계액상특정명현,정내화정계무명현석출.분석인위:반고태Ti14합금냉각과정중경력료포정응고,포정반응발생재액상/β/Ti_2Cu삼선교점처,사득삼선교점처적용질분포흔불규칙,포정상적형핵화생장형태발생개변,동시,냉각방식불동영향포정반응정도,종이영향후서적공석조직,사득불동냉각방식냉각후산생료불동적조직형모.
The microstructure and phase composition of semi-solid Ti14 alloy (α-Ti+Ti_2Cu) with different cooling modes (furnace cooling-FC, air cooling-At 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 Ti14, but influence the morphology and distribution of Ti_2Cu. Tile microstructure of Ti14 after furnace cooling consisted of granular Ti_2Cu precipitates, which distributed in a certain direction presenting strip and dentritic structure. After air cooling, Ti_2Cu 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 periteetic solidification during cooling process. The peritectic reaction occurs in the liquid/β/Ti_2Cu 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 microstrncture with different cooling modes.