Preliminary study of 3D ball-milled powder processing and SPS-accelerated densification of ZnSe ceramics

Spark plasma sintering (SPS) was utilized to achieve the densification of ZnSe ceramics with a simple 3D ball-milling powder processing. The morphology evolution of powders during the ball milling process and the densification and microstructure of fabricated ceramics were investigated. The effective ball-milling of 8h obviously reduced the particle size and the full densification of ZnSe ceramics was achieved at the sintering temperature of 900 °C. The lower heating rate could obtain the denser ceramics with fewer pores and fine microstructure but serious carburization, and higher heating rate accelerated the grain growth. The optimized heating rate of 5 °C/min obtained the fine grain size of ~5.0 μm. Some challenging issues of fundamentals and technologies were proposed to improve the optical quality of ZnSe ceramics by SPS.