Postsintering

Postsintering refers to processing steps performed on a sintered part after the primary sintering stage. The aim is to refine density, microstructure, and properties, or to prepare the part for service by improving wear resistance, strength, or surface finish.

Common post-sintering techniques include hot isostatic pressing (HIP) to close porosity and increase density; diffusion-based heat treatments to adjust carbide distributions and phase balance; surface finishing such as grinding, lapping, or polishing; coatings or surface treatments; infiltration or impregnation with another metal to create a composite; and post-sintering forming operations such as hot forging or hot forming to modify properties. These steps can address residual porosity, improve dimensional stability, and tailor properties for specific applications.

Applications are widespread in powder metallurgy components such as gears, bearings, and cams, as well as structural ceramic parts used in high-temperature machinery. In metal additive manufacturing, post-sintering processes such as HIP and heat treatment are commonly used to achieve full density and the desired mechanical properties after printing.

Quality control typically includes density measurement, microstructure analysis, hardness testing, wear testing, and residual stress assessment, along with non-destructive testing methods to detect porosity, cracks, or distortion. Limitations include processing costs, potential distortion or grain growth during treatment, and compatibility issues in infiltration or coating steps. Overall, postsintering is a critical step for converting sintered bodies into functional, reliable components.