Patent ID: 7250123

Claim:
A method of manufacturing a composite construction comprising the steps of: (a) forming a core material molding by mixing a mixture of a metal powder that is a metal composition constituting a first hard particle composed of at least one of carbides, nitrides and carbonitrides of metals of Groups 4 a , 5 a and 6 a of the Periodic Table, a binder metal powder, and an organic binder, or a mixture of a metal powder that is a metal composition constituting a first ceramic particle composed of at least one of carbides, nitrides and carbonitrides selected from the group consisting of metals of Groups 4 a , 5 a and 6 a of the Periodic Table, Al, Si and Zn, a sintering additive powder, and an organic binder, and then molding said mixture in a continuous shape; (b) forming a composite molding by forming a shell layer molding having a different composition from said molding obtained in the step (a), and disposing said shell layer molding so as to coat the outer periphery of said core material molding obtained in the step (a); and (c) sintering said composite molding such that said metal powder of said metal composition constituting said first hard particle or said first ceramic particle is made into ceramic and its volume is expanded, wherein the ratio of the residual free carbon amount C in in the core material to the residual free carbon amount C out in the shell layer, C in /C out , is set to the range of 0.5 to 2.