3-D PROFILES AND SURFACE-TOPOGRAPHY OF ALUMINA COMPACTS

A non-contacting laser scanning profilometer, with associated hardware and software, is used for the determination of the overall shape and surface topography of cylindrical alumina compacts. The change in the shape distortion of the cylinder, defined as (R(max)-R(min))/R(min) (R is the radius of the compact), was monitored, as a function of the am bient temperature, during sintering. During sintering, an increase in the diameteral distortion values were observed. Certain surface topogr aphic characteristics, also obtained by the laser scanning of the surf aces of the green compacts, were used to characterise the agglomerate deformation and breakdown. The deformation of agglomerates starts at v ery low compaction pressures. However, the inter-agglomerate pores are not eliminated until a compaction pressure of 37 MPa.