Processing of Bulk Alumina Ceramics Using Laser Engineered Net Shaping

Application of rapid prototyping (RP) in ceramics manufacturing is motivated by advances in engineering ceramics where attaining complex shapes using traditional processing is difficult. Laser Engineered Net Shaping (LENS^™), a commercial RP process, is used to fabricate dense, net-shaped structures of α-Al₂O₃. Shapes such as cylinder, cube, and gear have been fabricated successfully with 10–25 mm section sizes. As-processed structures show anisotropy in mechanical properties with a high compressive strength normal to the build direction and columnar grains along the build direction. Heat treatment did not alter strength and anisotropy, but increased the grain size from 6 to 200 μm and hardness from 1550 to 1700 Hv.