Abstract
The sintering of porous bodies for catalytic purposes requires a compromise between strength and specific surface, since temperature and time have opposing effects on these properties. The present investigation on fine powder compacts of Cr2O3 and W was carried out to establish the conditions under which specific surface and strength could be optimized. Hence, sintering temperature and atmosphere were varied. Cylindrical specimens were used to measure specific surface (BET), permeability, and indirect tensile strength. Pore and surface structure were studied by electron-microscopic methods. It has been shown that sintering in nitrogen yields the best results as far as the combination of strength and accessible surface area is concerned. However, if high permeability and high strength are required, hydrogen is the best sintering atmosphere.
Notes
* Manuscript received 24 May. Contribution to a Symposium on ‘The Role of Surface Properties in Powder Metallurgy’ to be held in Eastbourne on 20 and 21 November 1972.