Review: liquid phase sintering

TLDR

Liquid phase sintering (LPS) is a high‑performance powder‑based process that forms multi‑phase components by sintering under conditions where solid grains coexist with a wetting liquid, and it is widely applied to engineering materials such as engine connecting rods and high‑speed cutting inserts, with scientific understanding beginning in the 1950s and ongoing research gaps. The review aims to outline the densification and microstructure evolution that occur when mixed powders are heated to LPS temperatures, drawing on over 2,500 publications. The authors review these studies to analyze the densification and microstructure evolution that occur during heating of mixed powders to LPS temperatures. Quantitative process models derived from LPS studies are now incorporated into computer simulations that predict component dimensions, microstructure, and properties.

Abstract

Liquid phase sintering (LPS) is a process for forming high performance, multiple-phase components from powders. It involves sintering under conditions where solid grains coexist with a wetting liquid. Many variants of LPS are applied to a wide range of engineering materials. Example applications for this technology are found in automobile engine connecting rods and high-speed metal cutting inserts. Scientific advances in understanding LPS began in the 1950s. The resulting quantitative process models are now embedded in computer simulations to enable predictions of the sintered component dimensions, microstructure, and properties. However, there are remaining areas in need of research attention. This LPS review, based on over 2,500 publications, outlines what happens when mixed powders are heated to the LPS temperature, with a focus on the densification and microstructure evolution events.