CAJ | 학술논문

利用Gleeble-3800型热模拟试验机对经过3次真空自耗熔炼的Ti-44Al-3Ta-0.3(Cr,W)(摩尔分数，%)合金样品进行热模拟等温压缩试验，研究该合金在1150~1250℃及0.01~1 s-1应变速率下高温变形后的宏观与微观组织演变。结果表明，在高温变形过程中，变形使合金中的组织由粗大的铸态γ/α2近片层组织演变为细小的近等轴γ/α2组织。变形过程中原始片层组织发生了不同程度的动态再结晶，动态再结晶是引起组织演变的主要原因。该合金的动态再结晶形核主要由位错塞积和孪晶形核控制。最佳高温塑形变形温度为1200℃，应变速率小于1 s-1。
이용Gleeble-3800형열모의시험궤대경과3차진공자모용련적Ti-44Al-3Ta-0.3(Cr,W)(마이분수，%)합금양품진행열모의등온압축시험，연구해합금재1150~1250℃급0.01~1 s-1응변속솔하고온변형후적굉관여미관조직연변。결과표명，재고온변형과정중，변형사합금중적조직유조대적주태γ/α2근편층조직연변위세소적근등축γ/α2조직。변형과정중원시편층조직발생료불동정도적동태재결정，동태재결정시인기조직연변적주요원인。해합금적동태재결정형핵주요유위착새적화련정형핵공제。최가고온소형변형온도위1200℃，응변속솔소우1 s-1。
The samples of Ti-44Al-3Ta-0.3(Cr,W) (mole fraction,%) were hot compressed in the temperature range of 1 200-1 300℃and strain rate range of 0.01-1 s-1 for high temperature flow behavior and microstructure evolution study. The results show that the microstructure of the alloy evolves from as-cast big sizeγ/α2 to small size near-equiaxedγ/α2. The dynamic recrystallization (DRX) is the main reason that origin lamella changes during the hot deformation. The main nucleation mechanism of the DRX is controlled by the twins and the dislocation tangle growth. The optimum temperature for hot forming of the alloy is 1 200℃, and the strain rate is less than 1 s-1.