EFFECT OF GRAIN GROWTH ON HOT-PRESSED OPTICAL MAGNESIUM FLUORIDE CERAMICS.

Article abstract of DOI:10.1111/j.1151-2916.1988.tb05034.x

An optical MgF//2 ceramic was hot-pressed at 838 to 983 K with 241-MPa pressure. In the early stages of grain growth the mechanical strength was directly proportional to grain size, which appeared to contradict the expectations of the Petch and Knudsen relations. Optical transmission was inversely proportional to grain size, especially in the visible wavelength. This study thus demonstrates a particular case in which increasing grain size promotes higher mechanical strength but lower optical transmission.