Processing and characterization of nanocrystalline molybdenum disilicide (MoSi(sub 2)) consolidated by hot isostatic pressing (HIP).

摘要

This work studied the effect nanocrystalline processing may have on mechanical properties of MoSi(sub 2) and the ease with which MoSi(sub 2) powder can be processed into a bulk shape. (MoSi(sub 2) presently is limited by poor strength above 1000 C and brittleness below DBTT.) This work studied cold and hot isostatic pressing (CIP, HIP). The attrited, CIPed, and HIPed samples were characterized by chemical analysis, XRD, SEM, microhardness, optical microscopy, and quantitative metallography (porosity, density). Fracture toughness of the nanocrystalline MoSi(sub 2) was found to be a factor of two higher than conventional MoSi(sub 2) and the hardness of 1500 C-HIPed compacts were higher, as well. Modulus test showed the calculated elastic constants to be higher than the original Cerac material.