Development of functionally graded hard material

Abstract

A functionally graded material (FGM) is a compound of two different materials with gradient composition. In addition to combining the characteristic of two materials, FGM show new characteristic. The concept of FGM was applied to hard material. The material which consists of ceramic surface layer and cemented carbide core and an intermediate layer with graded two materials showed excellent performance for cutting tool. And we studied on FGM which is composed of cobalt composition graded cemented carbide layers and steel substrate for oil drilling stabilizer. FGM stabilizer showed excellent wear resistance compared with conventional type. The idea of FGM was applied for ceramic coating technology, too. We succeeded balancing breakage resistance and adhesion by FGM coating technology. This paper introduces these materials feature and performance.