Wear-resistant member for use in internal combustion engine and method for producing the same

A method for producing a wear-resistant member formed of a combination of a ferrous sintered body and a ferrous base body for use in an internal combustion engine comprising the steps of:

• (a) compressing a ferrous powder mixture to provide a compressed powder body, said compressed body consisting of 0.5 to 4.0% by weight carbon, 0.2 to 3.0% by weight phosphorus, 10.0 to 20.0% by weight chromium, 0.1 to 2.0 by weight tungsten, and the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300.mu.,
• (b) mounting said compressed powder body on said ferrous base body to provide a combination member, said ferrous base body having a melting point higher than that of said compressed powder body,
• (c) placing said combination member in a sintering furnace and heating said combination member to a temperature higher than the liquid-phase temperature of said compressed powder body and lower than the melting point of said ferrous base body so as to thus perform sintering of said compressed powder body,
• (d) continuously cooling said combination member to thereby produce a ferrous sintered body having a porosity of 0.2 to 10% by volume, at least 40% of which is sintering pores having a pore size of not more than 250.mu., said sintered body being bonded to said ferrous base body by diffusing diffusion elements of said compressed powder body into said ferrous base body.

A method for producing a wear-resistant member formed of a combination of a ferrous sintered body and a ferrous base body for use in an internal combustion engine comprising the steps of:

• (a) compressing a ferrous powder mixture to provide a compressed powder body, said compressed body consisting of 0.5 to 4.0% by weight carbon, 0.2 to 3.0% by weight phosphorus, 10.0 to 20.0% by weight chromium, 0.1 to 2.0% by weight tungsten, at least one material selected from the group consisting of nickel, copper and cobalt, the amount of said at least one material plus said tungsten being not more than 10% by weight, and the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300.mu.,
• (b) mounting said compressed powder body on said ferrous base body to provide a combination member, said ferrous base body having a melting point higher than that of said compressed powder body,
• (c) placing said combination member in a sintering furnace and heating said combination member to a temperature higher than the liquid-phase temperature of said compressed powder body and lower than the melting point of said ferrous base body so as to thus perform sintering of said compressed powder body,
• (d) continuously cooling said combination member to thereby produce a ferrous sintered body having a porosity of 0.2 to 10% by volume, at least 40% of which is sintering pores having a pore size of not more than 250.mu., said sintered body being bonded to said ferrous base body by diffusing diffusion elements of said compressed powder body into said ferrous base body.

A method for producing a wear-resistant member formed of a combination of a ferrous sintered body and a ferrous base body for use in an internal combustion engine comprising the steps of:

• (a) compressing a ferrous powder mixture to provide a compressed powder body, said compressed body consisting of at least one powder selected from ferrous alloy powder or iron powder containing 0.5 to 7.0% by weight carbon and 0.1 to 5.0% by weight phosphorus, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300.mu.,
• (b) mounting said compressed powder body on said ferrous base body to provide a combination member, said ferrous base body having a melting point higher than that of said compressed powder body,
• (c) placing said combination member in a sintering furnace and heating said combination member to a temperature higher than the liquid-phase temperature of said compressed powder body and lower than the melting point of said ferrous base body so as to thus perform sintering of said compressed powder body,
• (d) continuously cooling said combination member to thereby produce a ferrous sintered body having a porosity of 0.2 to 10% by volume, at least 40% of which is sintering pores having a pore size of not more than 250.mu., said sintered body being bonded to said ferrous base body by diffusing elements of said compressed powder body into said ferrous base body.

A method for producing a wear-resistant member formed of a combination of a ferrous sintered body and a ferrous base body for use in an internal combustion engine comprising the steps of:

• (a) compressing a ferrous powder mixture to provide a compressed powder body, said compressed body consisting of 0.5 to 7.0% by weight carbon, 0.1 to 5.0% by weight phosphorus, 8.0 to 30.0% by weight chromium, not more than 10% by weight of at least one material selected from the group consisting of nickel, copper, cobalt and tungsten, and the balance being iron, and having a porosity of 12 to 20% by volume at least 40% of which is pores having a pore size of not more than 300.mu.,
• (b) mounting said compressed powder body on said ferrous base body to provide a combination member, said ferrous base body having a melting point higher than that of said compressed powder body,
• (c) placing said combination member in a sintering furnace and heating said combination member to a temperature higher than the liquid-phase temperature of said compressed powder body and lower than the melting point of said ferrous base body so as to thus perform sintering of said compressed powder body,
• (d) continuously cooling said combination member to thereby produce a ferrous sintered body having a porosity of 0.2 to 10% by volume, at least 40% of which is sintering pores having a pore size of not more than 250.mu., said sintered body being bonded to said ferrous base body by diffusing elements of said compressed powder body into said ferrous base body.