Accession Number : AD0771921

Title :   Hot Pressing and Mechanical Properties of Calcium Hexaboride.

Descriptive Note : Final rept.,

Corporate Author : ARMY MATERIALS AND MECHANICS RESEARCH CENTER WATERTOWN MASS

Personal Author(s) : Dutta,Sunil K.

Report Date : NOV 1973

Pagination or Media Count : 13

Abstract : CIUM BORIDESLightweight, high modulus calcium hexaboride was hot pressed to essentially theoretical density at a temperature of 1600 plus or minus 15C and a pressure of 6000 psi. Densification behavior was studied as a function of hot-pressing temperature for process characterization. The microstructure consisted of a CaB6 phase with a minor amount of free boron. Electron probe analysis indicated the presence of Ca-rich oxide at the grain boundaries. The micro-hardness, modulus of rupture, modulus of elasticity, and impact strength were determined. Average modulus of rupture was 19,000 psi, while an average modulus of elasticity was measured to be 55,000,000 psi. Examination of the fracture-exposed surfaces indicated predominantly transgranular fracture with distinct step-cleavage pattern. These data are representative of the 'as-received' calcium hexaboride compound commercially available in production quantities. (Author)

Descriptors :   *Borides, Ceramic materials, Calcium compounds, Hot pressing, Mechanical properties, High strength, Lightweight, Microstructure, High density

Subject Categories : Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE