热等静压制备粉末高温合金原始颗粒边界研究现状

Research status of prior particle boundaries for powder superalloy prepared by hot isostatic pressing

粉末高温合金作为先进高温材料被广泛应用于航空航天领域。热等静压(hot isostatic pressing,HIP)是粉末高温合金构件的制备方法之一,但是原始颗粒边界(prior particle boundaries,PPBs)的存在会极大的影响构件的性能。本文综述了热等静压制备粉末高温合金原始颗粒边界的研究现状,概述了原始颗粒边界的形成机理及其影响,总结了粉末高温合金中原始颗粒边界的消除方法,并对这些方法应用的可行性及有效性进行了分析和展望。原始颗粒边界的消除方法主要包括向粉末添加Hf、Nb等强碳化物形成元素,对粉末进行预热处理,真空动态脱气处理或等离子体滴凝处理;优化粉末制备工艺,选用纯度更高、尺寸分布更均匀的粉末:选用合适的热等静压工艺参数和工艺方式;对制件采取热挤压、退火、固溶处理和热等静压后处理等。

Powder metallurgy superalloy is an advanced high-temperature material,which has been widely used in the aerospace fields.Hot isostatic pressing(HIP)is one of the preparation methods for powder superalloy components.However,the presence of prior particle boundaries(PPBs)adversely affects the performance of the components significantly.The research status of PPBs for powder metallurgy superalloys prepared by HIP was reviewed in this paper,the formation mechanism and influence of PPBs in components were summarized,the removal PPBs methods in powder superalloys were proposed,and the feasibility and effectiveness of these methods were analyzed and prospected,including adding Hf,Nb,and other strong carbide forming elements to the powder,preheating the powder,using the vacuum dynamic degassing treatment or plasma droplet re-fining(PDR)treatment,optimizing the powder preparation process,selecting powders with higher purity and more uniform size distribution,selecting the appropriate HIP process parameters and methods,and applying hot extrusion,annealing,solution treatment and HIP post-treatment on the components.