Compressive strength and failure mechanism of chemical vapor deposited zinc sulfide from room temperature to 600°C

The compressive strength is a key factor for the design, application, and evaluation of the chemical vapor deposited (CVD) zinc sulfide (ZnS) in infrared optical engineering. However, to date, only the values of the compressive strength at room temperature (RT) have been reported. In this paper, the compressive strength of CVD ZnS from RT to 600°C is measured on the developed apparatus for high-Temperature mechanical testing. The failure mechanism in this temperature range is analyzed from both macro-And micro-scale. The study shows that the compressive strength of CVD ZnS from RT to 600°C has relatively large dispersion and weak temperature dependence. During compression, the specimen is crushed and the major fragments are slender columns which are almost as long as the specimen and have sides nearly parallel to the compression direction. The failure of the CVD ZnS is attributed to shear failure. Once shear slip occurs, the part below the slip plane is split to slender columns.