SUPERSOLIDUS LIQUID PHASE SINTERING OF BLENDED POWDERS

摘要

Supersolidus liquid phase sintering (SLPS) is an attractive approach for processing prealloyed powders. However, densification by SLPS often occurs within a narrow temperature range, which means the conditions for densification are close to the conditions for shape loss, limiting the widespread use of SLPS. This paper presents a process in which blended powder, typically a coarse prealloyed powder blended with a fine pure metal powder, was sintered via SLPS. It was found that blended powders broaden the sintering window, enabling densification without shape loss. As an example, a prealloyed master powder blended with carbonyl nickel powder were utilized to make Inconel 718 superalloy green performs, which were successfully sintered to near full density. This method is particularly appropriate to thermal processing of powder parts formed by the Three-Dimensional Printing Process because such parts have a large amount of porosity in the green state.