Method for near net shape manufacturing of high-temperature resistant engine components

Abstract

For near net shape manufacturing of a high-temperature resistant component of complex design a high melting-point part of an intermetallic phase provided as a metal powder is mixed with a binder, and from the feedstock such formed a green compact substantially matching the final contour is produced by metal injection moulding, into the pores of said compact that remain after removal of the binder the low melting-point part of the intermetallic phase is infiltrated. The brown compact thereby created is mechanically processed, if required, and subjected to a specific heat treatment depending on the metallic phases used in order to create the intermetallic phase. This permits engine components consisting of intermetallic phases and having a geometrically complex structure to be manufactured cost-efficiently.

What is claimed is: 
     
         1 . Method for near net shape manufacturing of high-temperature resistant engine components of geometrically complex structure by metal injection moulding, the engine components consisting of an intermetallic phase of a high melting-point part and a low melting-point part, characterized in that the high melting-point part provided as a metal powder is mixed with a binder, that a green compact of the engine component is first produced by metal injection moulding, that a porous brown compact is created after removal of the binder, that subsequently the low melting-point part of the intermetallic phase is infiltrated into the pores of the brown compact in the molten state and that finally the brown compact such prepared is subjected to a heat treatment generating the intermetallic phase. 
     
     
         2 . Method in accordance with  claim 1 , characterized in that the proportion of the low melting-point part of the intermetallic phase is variable and is determined by the proportion of pores after complete removal of the binder from the green compact. 
     
     
         3 . Method in accordance with  claim 2 , characterized in that the proportion of pores is determined by the setting of the mixing ratio between the metal powder and the two-component binder. 
     
     
         4 . Method in accordance with  claim 1 , characterized in that the infiltration of the molten and low melting-point part of the intermetallic phase into the porous brown compact is performed under pressure using the squeeze casting method. 
     
     
         5 . Method in accordance with  claim 1 , characterized in that the brown compact is mechanically processed after infiltration of the low melting-point part and before the heat treatment that creates the intermetallic phase. 
     
     
         6 . Method in accordance with  claim 1 , characterized in that a polymer two-component binder is used, where the first binder component is removed from the green compact created by metal injection moulding, and the second binder component is removed during infiltration of the low melting-point part of the intermetallic phase. 
     
     
         7 . Method in accordance with  claim 1 , characterized in that the first binder component is removed chemically, catalytically and/or thermally, and the second binder component is removed thermally.