Optical Ceramics Obtained by Hot Pressing of CVD-ZnSe Powder

The influence of mechanical grinding conditions of high-purity chemical vapor deposition (CVD) zinc selenide (ZnSe) powders on their particle size distribution, their sintering process, and the transparency of optical ceramics has been studied. Powders with an optimal granulometric composition have been obtained, having an average particle size of 0.3 μm with a maximum of not more than 1 μm. These parameters have been achieved by grinding the powders in a planetary ball mill for 20 h at a grinding jar rotation speed of 150 rpm. ZnSe optical ceramics have been fabricated by a combination of hot pressing and subsequent hot isostatic pressing of CVD powders. The maximum transmission for 2 mm thick samples has been 69% (close to theoretically achievable) at a wavelength of 14 μm. The combination of characteristics of the CVD ZnSe powders subjected to additional grinding shows their promise for use in optical ceramic technology.