Flexural properties of chemical vapor deposited zinc sulfide at high temperatures

The flexural properties of chemical vapor deposited (CVD) zinc sulfide (ZnS) above 600 °C are studied for the first time. The bending strength increases up to 600 °C and then decreases rapidly. The Young's modulus initially decreases, reaches the minimum value near 900 °C, and then increases as temperature increases. Recrystallization occurring above 800 °C will reduce the strength and enhance the stiffness. Phase transformation at 1000 °C will increase both strength and stiffness. CVD ZnS shows completely linear deformation behavior below 800 °C. Nonlinearity occurs when temperature is greater than 800 °C and increases significantly as temperature or holding time increases because of recrystallization. The mechanisms being responsible for the aforesaid mechanical behavior are expounded by macro and micro analysis. The direct evidence for recrystallization of CVD ZnS at high temperatures is observed.