PURPOSE: To prevent the peeling on an interface by connecting two layers of a titanium substrate and a niobium substrate with diffusion connection, and forming the face of the niobium substrate into a friction face.

CONSTITUTION: A nonmagnetic titanium or titanium alloy plate 3 is connected to the back plate of a niobium alloy plate by diffusion connection, and the face of the niobium substrate 1 is formed into a friction face. Both plates 1, 3 are composed of materials with similar thermal expansion coefficients, no peeling occurs at the high temperature, the niobium alloy with high-temperature hardness is used for the friction face, the abrasion resistance at the high temperature is improved, and the wear on the surface layer is improved. The connection on an interface and the reliability of abrasion are improved.