Liquid phase diffusion bonding method of metal machine part and such metal machine part

A melt bonding and liquid phase diffusion bonding method of a metal machine part characterized by interposing an amorphous alloy foil for liquid phase diffusion bonding between metal materials including at bevel faces of at least one metal material of metal materials to be bonded,

• performing primary bonding by melt bonding said amorphous alloy foil and said metal materials by resistance welding to form a joint, wherein said resistance welding melts said amorphous metal foil and said bevel faces of said at least one metal material, then performing secondary bonding by liquid phase diffusion bonding by reheating said joint to at least the melting point of said amorphous alloy foil, then holding it there to complete an isothermal solidification process of said joint;
• characterized in that said at least one of said metal materials is a cylindrical metal material and in that a V-bevel is formed at an end of said cylindrical metal material so that, when bringing the end of said cylindrical metal material into abutment with the surface of another metal material for primary bonding, an inner surface bevel height A and an outer surface bevel height B of said cylindrical metal material with respect to the abutting contact point and a distance C from said abutting contact point to the outer circumference satisfy the following relation (1):
• 0.2≦B/A≦1 and C/t≦0.5 (1)
• where A is an inner surface bevel height of said cylindrical metal material, B is an outer surface bevel height of said cylindrical metal material, C is a distance from an abutting contact point of the cylindrical metal material to the outer circumference, and t is the thickness of the cylindrical metal material;
• characterized in that a maximum residual height of the bevel ends after said primary bonding is not more than three times the thickness of said amorphous alloy foil.