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

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.