1.Purity:92%, 95%, 96%, 99%, 99.7%2.Good mechanical strength 3.Excellent electrical insulation 4.High-frequency loss 5.Good thermal conductivity 6.Heat, wear and corrosion resistance.Application: Alumina is the best-known advantaced ceramicmaterial, is widely used in 1.Automotive 2.Petro-chemical 3.Fluid control 4.Material transfer 5.Industry 6.Electrical and electronic 7.Semiconductor 8.Sapphire is single-crystal alumina.