W和Re对固溶态镍基单晶高温合金变形和再结晶的影响  

EFFECT OF W AND Re ON DEFORMATION AND RECRYSTALLIZATION OF SOLUTION HEAT TREATED Ni-BASED SINGLE CRYSTAL SUPERALLOYS

作　　者：濮晟[1,2] 谢光[2,3] 郑伟[2] 王栋[2,3] 卢玉章[2] 楼琅洪[2] 冯强[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083 [2]中国科学院金属研究所,沈阳110016 [3]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《金属学报》2015年第2期239-248,共10页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50901079;国家重点基础研究发展计划项目2010CB631201;国家高技术研究发展计划项目2012AA03A513资助~~

摘　　要：镍基单晶高温合金固溶处理后,分别经过Brinell硬度计压痕和吹砂引入变形,热处理后观察再结晶,研究了W和Re元素对固溶态镍基单晶高温合金变形和再结晶的影响.结果表明,加入W和Re后,单晶高温合金变形后位错密度增大,位错缠结增多,再结晶形核时间滞后,即再结晶孕育期延长,再结晶深度明显减小.单晶高温合金经吹砂后,表面显微硬度明显增加,加入W和Re后,变形深度减小,再结晶晶界迁移速率最大值降低,且沿着再结晶深度方向,晶界平均迁移速率的变化与显微硬度变化趋势一致.Ni-based single crystal superalloys have been widely used for blades and vanes in gas turbine.However, recrystallization（RX） induced by residual strain has been a serious problem for the application of single crystal superalloys. In previous work, effect of microstructure, such as g’, g/g’ eutectics and carbides, as well as heat treatment parameters, on the RX behavior have been studied. However, the effect of alloy elements on the RX behavior has rarely been reported. Therefore, in this work, the effect of the important solution strengthening elements,W and Re, on the deformation and RX of solution heat treated Ni-based single crystal superalloys was investigated.At first, two single crystal superalloys were prepared, and W and Re were added into one alloy among them. After solution heat treatment, these two single crystal superalloys were deformed by shot-peening or Brinell indentation.Then these deformed samples were heat treated to observe the microstructure of RX. It indicated that RX depth decreased with the addition of W and Re irrespective of deformation mode and heat treatment temperature. Short time heat treatment experiment of indented and shot-peened samples both indicated that incubation period of RX was prolonged and nucleation of RX was slowed with the addition of W and Re, which verified that RX was suppressed by W and Re. After shot-peening, micro-hardness of the alloy with W and Re increased, but the depth of deformation zone was obviously reduced. Higher density of dislocation was found in the single crystal superalloy with W and Re, and also lots of dislocation tangles were observed. So, in this alloy, dislocation annihilated slowly, that is,recovery was slowed down, which prolonged the incubation period of RX. During the process of RX grain growth,the maximum RX grain boundary migration velocity was reduced with the addition of W and Re. Moreover, the change of mean RX grain boundary migration velocity showed the same trend with the micro-hardness along the direction of RX depth.

关 键 词：镍基单晶高温合金 再结晶 位错 显微硬度 W RE 

分 类 号：TG132.3[一般工业技术—材料科学与工程]