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摘要：对[001]取向镍基单晶合金进行预压缩处理，获得P-型筏状结构后，进行拉伸蠕变实验，测定预压缩态合金与热处理态合金的相对蠕变性能。结果表明：在800℃/600MPa条件下，预压缩态合金的初期蠕变应变及稳态蠕变速率相对较高，而持久寿命相对较短。TEM观察显示，预压缩态合金在蠕变初始阶段除了基体中的{111}<110>多滑移启动外，位错还以层错和超位错的形式切入γ’相。在980-1020℃温度区间，恒定载荷200MPa条件下，预压缩态合金的稳态蠕变速率相对较低，持久寿命相对较长，在稳态蠕变初期P型有效地抑制了位错沿垂直γ/γ’界面的攀移运动，而在稳态蠕变中期γ’相被稠密的位错网包围,位错难以切入,合金的蠕变抗力提高.

ABSTRACT After P-type rafted structure was obtained by compressive creep of a nickel base single crystal superalloy with [001] orientation, creep tests were performed to examine in more detail the relative creep behavior of rafted (pre-compression) and cuboidal (as-heat treated) γ’ microstructures. The experiments show that, at 800℃ and 600MPa, the alloy with the P-type structure has both much higher strain of primary creep and steady state creep rate, and rupture lives are shorter. TEM examination of the microstructures of the P-type structure indicates that, in addition to {111}<110>-slip system operated in γ matrix, the γ’ precipitates are cut by some superlattice dislocations and a few stacking fault. At low stress of 200MPa and temperature range from 980℃ to 1020℃, the glide-climb process along γ/γ’ interfaces is impeded most efficiently by P-type rafted structure, the alloy exhibits a lower minimum creep rate and longer rupture lives. It is deduced that the tensile creep strength of the alloy is improved by suitable pre-compression treatment.