Using friction stir processing to form foamed metal precursors
View Patent ↗The present invention provides a qualitatively-stable functionally gradient material precursor having gradient material composition, as well as a production method of the functionally gradient material precursor, at low cost. Further, the present invention provides a functionally gradient material having gradient material composition, or having both gradient material composition and gradient porosity, so as to achieve high-functionality; as well as a production method of the functionally gradient material. A functionally gradient material precursor is formed by the steps of: forming plural kinds of metal foam precursors, each obtained by performing heat treatment on a metal member so that a plurality of pores are generated within the metal member, by making the material composition of the metal member different; and friction stir welding the plural kinds of metal foam precursors. Further, a functionally gradient material is formed by performing heat treatment on the functionally gradient material.
1. A method for producing a functionally gradient material precursor comprising the steps of:
forming a plurality of metal foam precursors by forming a plurality of assemblies each including metal members and blowing agents, and performing friction stir welding on each of the plurality of assemblies so that the blowing agents are caused to disperse within the metal members and the metal members are joined to each other, wherein material compositions of the respective metal members of the plurality of assemblies are different, and at least one of the plurality of assemblies compirses a laminate including a blowing agent and a pair of metal plates laminated to each other with the blowing agent sandwiched in between; and
forming the functionally gradient material precursor by arranging the plurality of metal foam precursors formed in the step of forming the metal foam precursors so as to contact each other, and performing friction stir welding on the plurality of metal foam precursors arranged so as to contact each other in the step of forming the plurality of metal foam precursors, by arranging the plurality of assemblies so as to contact each other, and performing friction stir welding on all of the plurality of assemblies arranged so as to contact each other.
2. The method for producing the functionally gradient material precursor according to claim 1 , wherein, in the step of forming the functionally gradient material precursor by performing friction stir welding on the plurality of metal foam precursors arranged so as to contact each other, a dense metal portion formed of a desired material composition is friction stir welded to part or all plurality of metal foam precursors.
3. A method for producing a functionally gradient material comprising the steps of:
forming a plurality of metal foam precursors by forming a plurality of assemblies each including metal members and blowing agents, and performing friction stir welding on each of the plurality of assemblies so that the blowing agents are caused to disperse within the metal members and the metal members are joined to each other, wherein material compositions of the respective metal members of the plurality of assemblies are different, and at least one of the plurality of assemblies comprises a laminate including a blowing agent and a pair of metal plated laminated to each other with the blowing agent sandwiched in between,
forming a functionally gradient material precursor by arranging the plurality of metal foam precursors formed in the step of forming metal foam precursors so as to contact each other, and performing friction stir welding on the plurality of metal foam precursors arranged so as to contact each other, or in the step of forming the plurality of metal foam precursors, by arranging the plurality of assemblies so as to contact each other, and performing friction stir welding on all of the plurality of assemblies arranged so as to contact each other; and forming the functionally gradient material by performing heat treatment on the functionally gradient material precursor formed in the step of forming a functionally gradient material precursor so that each interior of the metal foam precursors is foamed to form metal foam portions.