Preparation And Properties Of New Ceramic Corundum Abrasives

New ceramic corundum abrasives were prepared through pressureless sintering of the precursor made by sol-gel method. The effects of different additives, additives combination and amounts, granulation methods and sintering process on the microstructure, single particle compressive strength and microhardness of the abrasives were analyzed systematically by using SEM, diamond single particle compressive strength tester and microhardness tester.The results showed that the properties of the abrasives were influenced intensely by additives combination and amounts, granulation methods, heating rates, sintering temperature, holding time in the sintering temperature. The grain size and shape could be well controlled by choosing suitable additives. Proper additives combination would promote sintering of alumina, restrain the growth of grains, improve the single particle compressive strength. With appropriate additives amounts, the grain size was reduced, the strength and microhardness of the abrasives were improved. Direct granulation method from dry gel was good to increase the density of green bodies and the strength of sintered bodies. Higher heating rate in low temperature period would lead to macrocracks, while much lower heating rate in high temperature period would result in the overgrowth of abrasive grains, which would deteriorate the properties of abrasives. Sintering temperature had obvious effect on the properties of the abrasive, higher sintering temperature would induce the growth of the grain and decrease the strength of abrasives. Holding time in the researched range had little influence on the microstructure of abrasives, but proper holding time would improve the single particle strength of abrasives.