Patent ID: 8557010

Claim:
Fused particles comprising, by weight percent: more than 15% but less than 55% of Al 2 O 3 ; more than 20% but less than 45% of TiO 2 ; more than 3% but less than 30% of SiO 2 ; less than 20%, in total, of at least one selected from the group consisting of ZrO 2 , Ce 2 O 3 , and HfO 2 ; less than 1% of MgO; more than 1% but less than 15%, in total, of at least one selected from the group consisting of CaO, Na 2 O, K 2 O, SrO, B 2 O 3 , and BaO, wherein the weight percents are based on a sum of all oxides being 100 wt %, wherein the fused particle is obtained by melting the Al 2 O 3 the TiO, the SiO 2 , less than 20%, in total, of at least one selected from the group consisting of ZrO 2 , Ce 7 O 3 , and HfO 2 ; less than 1% of MgO; more than 1% but less than 15%, in total, of at least one selected from the group consisting of CaO, Na 2 O, K 7 O, SrO, B 7 O 3 , and BaO to a molten liquid, cooling the molten liquid into a solid mass, and grinding the solid mass to produce the fused particle.