High efficiency ELID grinding of alumina ceramics

More and more ceramic parts are used to substitute for metal counterpart due to their excellent physical, chemical and mechanical properties. However, ceramics, especially structural ceramics, are extremely difficult to machine because of their high hardness and brittleness. Some parts of large batch production have large machining allowances and the machining efficiency is very low with conventional grinding method. So it is of great importance to research the high efficiency grinding technology of hard and brittle material. In recent years, grinding techniques for precision machining of brittle materials have been improved by using super abrasive wheels and precision grinding machines. A new method of electrolytic in-process dressing (ELID) grinding developed by Dr. Hitoshi Ohmori has been adopted for the ultra precision machining of hard and brittle materials. It has been widely used in fine abrasive grinding for its in-process dressing. In this paper, the cast iron bond diamond wheel and ELID grinding technology are used on a surface grinder to research the high efficiency grinding technique. Alumina ceramics have been machined both by the cast iron bond diamond wheel with ELID grinding and by the resin bond diamond wheel. The grinding process adopts plunge grinding and a Kistler Dynamometer is used to measure the grinding force. It has been found that the grinding force of ELBD grinding is apparently smaller than the grinding force of the resin bond wheel. Under the same machining conditions, it is about 2/5-3/5 of the force for using the resin bond wheel. The result indicates that the grinding efficiency can be highly improved by applying ELID grinding technology. In addition, the in-process dressing can keep the grinding wheel sharp. This property is also of benefit to the continuous high efficient grinding of hard and brittle materials.