HOT PRESSING OF DIBORIDE REINFORCED OXIDE MATRIX COMPOSITES

Abstract

Composites of particulate TiB2 in matrices of Y2o3-stabilized Zro2, Y2o3 and Al2o3 were prepared by vacuum hot pressing in graphite tooling. Results of hot pressing the oxides and the composites are presented. X-ray diffraction and scanning electron microscopy were used to characterize the materials before and after processing. The effects of processing temperature, powder size, pressure and time are emphasized. Chemical reactivity of the diborides with oxygen presents problems which can be minimized by careful control of vacuum and processing sequence. Resultant composite compacts show little evidence of reaction at particle-matrix interfaces.