Sintering Al_2O_3-Cr Composites Made From Micro- and Nanopowders

摘要

This paper presents the results of studies on sintering Al_2O_3 - Cr composites of different chemical compositions (from 25 to 75 vol. percent of each component). The factor analyzed was the influence of time (from 15 to 60 min.), temperature (from 1200-1600 deg C), pressure (0.5 and 30 MPa) and powder graining (for Al_2O_3 powders - 80 nm or I mu m) on the density of sinters obtained. It was found that nanopowder composites are characterized by a higher density (by about 1-2 percent) than the micropowder composite, the remaining conditions of the process intact. Using the pressure of 30MPa allows obtaining of a definite sintering degree at a temperature of about 200 deg C lower than at a pressure of 0.5 MPa.