单晶镍基合金的热处理及对蠕变性能的影响  

Influence of Heat Treatment on Creep Properties of a Single Crystal Superalloy

作　　者：王明罡[1,2] 田素贵[1] 于兴福[1] 李唐[1] 夏丹[1] 雷军[2] 

机构地区：[1]沈阳工业大学材料科学与工程学院,沈阳110023 [2]长春工业大学材料科学与工程学院,长春130012

出　　处：《材料工程》2009年第3期56-61,共6页Journal of Materials Engineering

基　　金：国家自然基金(50571070)

摘　　要：根据差热曲线分析制定出合金的热处理工艺,结合蠕变性能测试及组织形貌观察,研究了固溶温度对一种含Re单晶镍基合金蠕变性能的影响。结果表明:铸态合金组织中存在明显的成分偏析,其中元素Cr,Co,Re富集于枝晶干,元素Al,Ta,W等富集于枝晶间。采用不同温度固溶处理,合金具有不同的蠕变寿命。当固溶温度提高到1320℃时,可使合金成分的均匀化程度提高,难溶元素得到充分扩散,降低合金的枝晶干/间成分偏析,并抑制合金中TCP相的析出,可显著提高合金的蠕变抗力。与1300℃固溶处理相比较,合金经1320℃高温固溶处理后,其在1072℃,137MPa条件下的蠕变寿命由37h提高到230h。Heat treatment techanique of the alloy is determined according to the analysis of the differential thermal curve. By means of measurement of creep curves and microstructure observation, an in- vestitation has been made into the influence of the solution temperature on the creep properties od a single crystal nickel-based superalloy. Results show that an obvious segregation of alloying elements occurs in as cast nickel-based superalloy, thereinto, the elements Cr, Co and Re are richer existed in the dendritic area, and the elements W, Ta, A1 are richer existed in the interdendritic area. The superalloy displays the various rupture lifetimes when using the different solution temperatures. When the solution temperature enhanced to 1320℃, the diffusion of the refractory elements W and Re in the alloy is promoted, which decreases the microsegregation of the elements W, Re in the dendritic/indendritic areas, and prostrains the precipitation of TCP phase, so that improves the creep resistance of tha alloy. Compared with solution treatment at 1310~C, after solution treated at 1320℃, the creep rupture lifetime of the superalloy is obviously enhanced to 230 h from 37 h under the applied stress of 137 MPa at 1072℃.

关 键 词：单晶镍基合金 固溶处理 组织结构 蠕变性能 

分 类 号：TG146.4[一般工业技术—材料科学与工程] TG132.3[金属学及工艺—金属材料]