This paper proposes the lapping stone which enables mirror finish for sticky soft metals, such as aluminum and copper. Then we examined the application of tribochemical reaction of perfluoropolyether oil to the finishing. The oil as a lapping fluid has, however, too high lubricity to generate the removal motion of the stone. Then the oil was introduced into the lapping stone in a capsulated form to supply the oil just to the grinding point. From the lapping results, the fluorine compound having good machinability was generated under high pressure and high temperature during the process and was observed on the ground surface of aluminum. This demonstrated the tribochemical reaction between the oil and the surface; the result was a significant improvement of the finishing efficiency and the surface quality of aluminum workpieces, as well as silicon wafers.
