Pressureless sintering of chromium diboride using spark plasma sintering facility

• Investigated the feasibility of creating pressureless sintering condition in SPS.
• Modified die design helped to attain pressureless condition in SPS facility.
• Achieved 93%ρth CrB2 by multi-step sintering methodology under PLS condition in SPS.
• Multi-step treatment results in higher density compared with single step sintering.

Sinterability of monolithic CrB2 was investigated under pressureless sintering condition using spark plasma sintering facility (SPS). Monolithic chromium diboride (CrB2) was sintered in a modified die setup instead of traditional/conventional plunger and die assembly. This kind of assembly creates pressureless sintering conditions in spark plasma sintering unit. The main objective of this modified setup is to couple the combined aspect of conventional pressureless sintering with fast heating. Densification experiments using CrB2 were conducted at temperatures in the range of 1600 °C to 2000 °C with different dwelling period (1–30 min) under no load condition. The effect of multi-step sintering treatment on the densification behaviour of CrB2 was also investigated. The density and the resulted microstructures of the sintered samples are presented and discussed in this paper.