The effect of boron liquid phase sintering on properties of Ni-, Mo- and Cr-alloyed structural steels

Boron is evaluated as the best sintering enhancing element in terms of densifying the iron-based materials by formation the liquid phase. The influence of boron addition (up to 0.6%) on the density, microstructure formation and the strength of the different prealloyed powders were studied. The specimens were sintered at 1200 °C for 60 min in hydrogen. Boron addition caused an increase of specimen density and formation of a new microstructure type. Microstructural analysis showed an interaction of boron with matrix alloying elements. The formation of borides caused the increase of microhardness and hardness values of matrix. The higher density and microhardness expressed in higher strength of materials.