Conventional Machining of Green Aluminum/ Aluminum Nitride Ceramics

Author Institution: Department of Industrial Engineering, The University of ToledoCurrent methods for producing ceramic parts rely on finish machining using diamond creep feed grinding or some other non-traditional machining method. As a result, machining may represent as much as 90% of the cost of some ceramic parts. This research project focused on creating dimensionally accurate parts made from green engineering ceramic bodies. These bodies were designed to be reaction sintered. Reaction sintering is a method which drastically reduces shrinkage, from about 20% to about 1%. This project investigated the use of conventional milling to machine ceramic green bodies. The green bodies, consisting of 80% aluminum and 20% aluminum nitride, were machined under feed, speed, and depth of cut conditions designed as a 23 factorial experiment. Also, green bodies of 20% aluminum and 80% aluminum nitride were prepared, presintered, and machined. The key measurements taken were the number of chips on the machined geometries of the green body caused by the mill. In the 23 factorial experiment all green bodies exhibited chipping when subjected to drilling and milling. Feed, speed, and depth of cut were found not to be significant in chipping. The machined presintered bodies did not exhibit any chipping when machined