摘要
采用扫描电镜、透射电镜等方法研究了一种镍基单晶高温合金在1000℃的高温低应力蠕变行为。实验结果表明:合金蠕变速率呈现出先减小再增大的变化趋势,当应变量达到一定临界值(1±0.2)%后,变形速率迅速上升,蠕变进入第三阶段。高温蠕变初始阶段的主要变形机制为a/2〈110〉{111}型位错环在基体内运动。合金在高温蠕变稳态阶段的主要变形机制为位错切割γ'相,切割位错主要有螺型位错对和[001]超位错两种形式。
A nickel-based single crystal superalluy was employed to study the high temperature creep under low applied stress behavior by using scanning electron microscope （SEM） , transmission electron microscope （TEM） and some other research methods. The main results are summarized as follows： Initially, there existed a decreasing strain rate regime with the strain rate eventually reaching a mini- mum which occurs within the creep plateau. Thereafter the creep strain rate increased dramatically in what will be referred to as the in- creasing ereep rate regime. The mechanism for primary creep is transverse glide of a/2（110） / 111 } dislocations in the matrix channels normal to the load axis. The mechanism fur the steady creep is superlattice dislocation cutting Y＇ precipitates, and the cutting dislocation is mainly composed of screw dislocation pair and [001 ] dislocation.
出处
《航空材料学报》
EI
CAS
CSCD
北大核心
2013年第3期1-5,共5页
Journal of Aeronautical Materials
关键词
单晶高温合金
高温
蠕变
位错
single crystal superalloy
high temperature
creep
dislocation
