Influence of parameters of high-energy ball milling on the synthesis and densification of magnesium aluminate spinel

Abstract

This study investigated the effect of planetary ball mill parameters on the particle size of a powder mixture of alumina and magnesia, the composition of synthetic magnesium aluminate spinel (MAS), and the subsequent densification of MAS. The results show that the particle size of the milled powders decreases gradually from 32.39 μm to 11.69 μm with the increase of milling time from 1 h to 7 h at milling speed of 120 rpm. The particle size of the milled powders decreases gradually from 42.92 μm to 9.00 μm as the milling speed was increased from 60 rpm to 240 rpm at a milling time of 3 h. Only a spinel phase can be obtained from these calcined powders when the starting powders of the calcined powders are milled for more than 1 hour or at above 60 rpm. The relative density and flexural strength of the sintered products exceed 86.67% and 105 MPa, respectively.

Keywords

• magnesium aluminate spinel
• planetary ball mill
• particle size
• microstructure