镍基粉末高温合金粉末直接锻造技术

Direct Powder Forging Technology of PM Nickel-based Superalloy

镍基粉末高温合金的完全致密化可以通过适当地处理实现,而细化微观组织可以通过再结晶形核实现。本文使用普通液压机且在大气环境下通过粉末直接锻造制备完全致密化的镍基粉末高温合金零件。通过边界取向差测定及分析镍基粉末高温合金零件的再结晶程度。通过Deform-2D/3D有限元软件对粉末直接锻造过程中的实际负载状态进行了模拟验证,同时分析了应力与致密度以及应变与再结晶度的关系。结果发现,相比于热等静压零件,经过粉末直接锻造后的镍基粉末高温合金零件的微观组织结构具有更高的再结晶程度和再结晶亚晶粒。零件的边缘处的再结晶程度高于零件中心,这与剪切应变速率有关。

The full densification of nickel-based powder superalloys can be achieved by proper treatment, while the fine microstructure can be achieved by recrystallization nucleation. The fully densified nickel-based powder superalloy parts were prepared by direct powder forging in atmospheric environment using ordinary hydraulic press. The recrystallization degree of nickel based powder superalloy parts was determined and analyzed by boundary orientation difference. The actual load state of direct powder forging process was simulated and verified by Deform-2 D/3 D finite element software. At the same time, the relationship between stress and density, strain and recrystallization degree was analyzed. The results show that the microstructure of Ni-based powder superalloy after powder forging has higher recrystallization degree and recrystallization sub-grain than that of hot isostatic pressing parts. The degree of recrystallization at the edge of the part is higher than that of the center of the part, which is related to the shear strain rate.