CAJ | 학술논문

采用液态金属冷却定向凝固炉制备Nb?16Si?24Ti?10Cr?2Al-2Hf合金，凝固速率分别为1.2、6、18、36、50 mm/min，随后对定向凝固速率为50 mm/min的合金进行(1400°C，10 h),(1450°C，10 h)和(1500°C，10 h)的热处理。研究了定向凝固速率和热处理温度对合金微观组织的影响。结果表明：合金的定向凝固组织主要由沿着试棒轴向生长的初生Nb5Si3相和耦合生长的Nbss/Nb5Si3共晶胞组成，在共晶胞边缘，有少量的Cr2Nb存在。横截面上共晶胞边界明显，随着凝固速率的增加，定向凝固组织明显细化，Nbss/Nb5Si3共晶胞形貌也发生变化。合金经过热处理，Nbss连成基体，部分Cr2Nb相熔解，微观成分偏析减小。经过(1450°C，10 h)热处理，实现了对过共晶Nb?Si基合金的组织优化。
채용액태금속냉각정향응고로제비Nb?16Si?24Ti?10Cr?2Al-2Hf합금，응고속솔분별위1.2、6、18、36、50 mm/min，수후대정향응고속솔위50 mm/min적합금진행(1400°C，10 h),(1450°C，10 h)화(1500°C，10 h)적열처리。연구료정향응고속솔화열처리온도대합금미관조직적영향。결과표명：합금적정향응고조직주요유연착시봉축향생장적초생Nb5Si3상화우합생장적Nbss/Nb5Si3공정포조성，재공정포변연，유소량적Cr2Nb존재。횡절면상공정포변계명현，수착응고속솔적증가，정향응고조직명현세화，Nbss/Nb5Si3공정포형모야발생변화。합금경과열처리，Nbss련성기체，부분Cr2Nb상용해，미관성분편석감소。경과(1450°C，10 h)열처리，실현료대과공정Nb?Si기합금적조직우화。
Nb?16Si?24Ti?10Cr?2Al?2Hf alloy was directionally solidified with withdrawal rates of 1.2, 6, 18, 36 and 50 mm/min and then heat treated at 1400, 1450 and 1500 °C with withdrawal rate of 50 mm/min for 10 h. The effects of withdrawal rate and heat treatment temperature on the microstructure were studied. The microstructure of directionally solidified alloy was composed of the primary Nb5Si3, Nbss/Nb5Si3 eutectic cells and Cr2Nb, which distribute paralleled to the growth direction. The microstructure becomes more refined with the increasing withdrawal rate, accompany with the evolution of eutectic cells morphology. After heat treatment, Nbss phase connects and forms a continuous matrix, and the Cr2Nb phase becomes smaller and distributes more dispersedly. After heat treatment at 1450 °C for 10 h, the alloy achieves balance between the optimization of microstructure and alleviation of solute segregation.