Reinforced composite mechanical component, and method for making same
View Patent ↗A mechanical part presents a main direction along which there extends a central zone forming a core and a peripheral zone forming a casing that surrounds the core. The core and the casing present a metallurgical bond between each other. The core is made of a first material presenting at least a metal matrix, and the casing is made of a second material presenting at least a metal matrix. The metal matrices of the first and second materials are based on the same metal, and at least one of the first and second materials is made of a metal matrix composite containing reinforcing elements dispersed in the metal matrix. The mechanical part can be used as a blade for a fan or a low pressure compressor.
1. A method of manufacturing a blade, comprising:
a) compressing a core and a casing to make a semi-finished product containing said core and said casing, said core and said casing including a metallurgical bond between each other resulting from said compression, said core including a first material that includes at least an aluminum based metal matrix, and said casing including a second material that includes at least an aluminum based metal matrix, and at least one of said first and second materials being made of a metal matrix composite containing reinforcing elements dispersed in said metal matrix;
b) forging the semi-finished product to obtain a blank with a quasi-final shape of the blade; and
c) machining said blank to provide a finished product forming said blade.
2. A method of manufacture according to claim 1 for obtaining a blade in which said first and second materials include said metal matrix composite containing said reinforcing elements dispersed in said metal matrix, wherein said reinforcing elements represent a percentage by weight of the composition of said metal matrix composite that varies progressively in said first material and in said second material in a direction from a center of said core towards a periphery of said casing, and wherein said compressing said core and said casing includes forming the core and the casing conjointly by a powder metallurgy technique.
3. A method of manufacture according to claim 1 , wherein said compressing said core and said casing includes performing, in succession:
a1) using said first material to make a rod extending in a longitudinal direction, said rod serving to form said core placed in a center of the mechanical part;
a2) using said second material to make a sleeve extending in a longitudinal direction, said sleeve serving to form the casing of the mechanical part by surrounding said core;
a3) inserting the rod into the sleeve to form an assembly; and
a4) passing said assembly through an orifice of small section to reduce at least one dimension of said assembly in a direction perpendicular to said longitudinal direction to create a metallurgical bond between said rod and said sleeve.
4. A method of manufacture according to claim 3 , wherein said passing said assembly through the orifice includes rolling or extrusion.
5. A method of manufacture according to claim 3 , wherein said passing said assembly through the orifice is performed at an elevated temperature.
6. A method of manufacture according to claim 5 , wherein said passing said assembly through the orifice is performed at a temperature of about 400° C.
7. A method of manufacture according to claim 1 , wherein said forging includes die stamping.
8. A method of manufacture according to claim 7 , wherein said die stamping is performed at a temperature of about 430° C. and a pressure of about 100 MPa.