一种镍基单晶高温合金高温持久性能的各向异性  

ANISOTROPY OF HIGH TEMPERATURE STRESS RUPTURE PROPERTY OF A Ni BASE SINGLE CRYSTAL SUPERALLOY

作　　者：刘金来[1] 金涛[1] 张静华[1] 胡壮麒[1] 

机构地区：[1]中国科学院金属研究所,沈阳110016

出　　处：《金属学报》2001年第12期1233-1237,共5页Acta Metallurgica Sinica

摘　　要：测定了一种镍基单晶高温合金［００１］，［０１１］和［１１１］三个取向的高温持久性能．结果表明，［００１］方向塑性最好，［１１１］方向寿命最长，而 ［０１１］方向各性能指标部较低 组织分析显示，［１１１］取向启动多个滑移系，形成界面位错网，且分切应力低。因而寿命长；［００１］取向等价滑移系最多，可有效钝化微裂纹，因而塑性最好；而［０１１］取向切应力高，滑移系少，形变孪晶易促进裂纹萌生，所以寿命短且塑性也低 三种试样在持久过程中郡形成一种沿枝晶方向的藤状 γ’，是由各枝晶间的微小取向差引起的，这些藤状γ’可以成为一种重要的裂纹源。The stress rupture test was conducted to a Ni base single crystal superalloy along [001],[011] and [111] orientations. The results show that the [001] oriented specimen has the best ductility and the [111] oriented specimen has the longest lifetime ,while the [011] oriented specimen is lower at these two properties. The longest lifetime in [111] orientation is resulting from the formation of dislocation networks due to multislip and its lower resolved shear stress. The [001] orientation specimen displays the best ductility owing to the blunting effect to microcrack stemming from multiple equivalent slip systems. The [011] oriented specimen has lower lifetime and bad ductility because of its higher resolved stress and less slip systems, even the deformation twinning also promotes the initiation of crack. A vine-like gamma' is formed along dendrite direction in all three orientations during test, which is caused by the small misorietation between dendrites and this vine-like gamma' can act as an important crack initiation site.

关 键 词：镍基单晶高温合金 持久性能 各向异性 

分 类 号：TG146.15[一般工业技术—材料科学与工程] TG132.32[金属学及工艺—金属材料]