Influence Of Heat Treatment On Nickel-base Single Crystal Superalloy Containing Re

Single crystal superalloys are the key material for the manufacturing the turbine blades and guide vanes used in the advanced aero-engine. Increasing the operating temperature and decreasing the cost is the main objective of the research in this field. Superalloys containing low Cr and high additive refractory elements such as W, Mo, Nb, Ta and Re can meet high temperature strength demand. Especially, the addition of Re improves the high temperature stress rupture properties dramatically, but it also makes the alloy cost boost to over one magnitude, which restricts the application of alloys seriously, so that, it is important to improve low cost nickel single crystal superalloysIn this paper, the heat treatment of a low cost nickel single crystal superalloys was studied, and-the as-cast microstructure of the alloy was analyzed. With the using of DSC, the heat treatment processes were researched, as results, the following conclusions can be obtained:The microstructure of single crystal was composed ofγ',γ' andγ/γ', there was no change occurred with the addition of Re, the only change is that the dendritc of the alloy become finer.Solid solution can improve the partition of the elements, with the increasing of the solid solution temperature, the dendrite become smaller.Aging temperature on gamma'morphology and size influence. With temperature rising, y'particle size increased, y'particle cubic degrees showing increased and then decreased, after 1290℃/4h solid solution treatment followed by 870℃/96h low temperature once aging heat treatment process, most gamma'particle cubic degree, The best heat treatment process of the alloys is that 1290℃/4h+870℃/96h, after this, the size ofγ'is about 0.5μm.