011取向DD6单晶高温合金薄壁持久性能

摘要

Thin-wall stress rupture properties of the second generation single crystal superalloy DD6 with [011] orientation were investigated at 760, 980℃ and 1070℃. The results show that the stress-rupture lives of thin-wall specimens are equivalent to those of standard specimens. The microstruc-tures of the alloy were studied at 760℃/590MPa, 980℃/270MPa and 1070℃0/270MPa, the γ' phase occurs local deformation at 760℃ , and the directional coarsening y' phase occurs and the rafting is formed at 980℃ and 1070℃.%采用薄壁试样研究了760,980,1070℃条件下[011]取向第二代单晶高温合金DD6的持久性能.结果表明:与标准试样(直径5mm)相比,DD6单晶高温合金薄壁试样的持久寿命与之相当.对合金760℃/590MPa,980℃/270MPa及1070℃/270MPa条件下组织分析发现:760℃合金γ’相局部发生变形,980,1070℃条件下DD6合金γ '相发生了定向粗化,形成筏排.