Up-grade recycling of metallic cutting chips by employing heavily-deformed in-situ composite technique

The present authors have realized that cutting chips may be identified utilizable for the strengthening of materials due to large plastic strain accumulated during cutting. The authors have proposed up-grade recycling techniques in which severe plastic deformation in room temperature air is utilized to cutting chip mixture of dissimilar materials, thereby consolidation and further accumulation of strain are simultaneously achieved. In this study, such composite materials are produced and evaluated with combinations of 6061 aluminum/IF steel and 6061 aluminum/pure copper. It is clarified that appropriate second phase cutting chip is a BCC metal. The ultimate tensile strength of the 6061 alloy is improved approximately up to 500 MPa (about 1.6 times that of the material before cutting) when the volume fraction of the IF steel is 20%. To predict the attainable maximum tensile strength by the current method, the Eshelby equivalent inclusion model is employed. The present method is identified to have a potential of realizing 713 MPa (about 2.3 times that of the material before cutting) in the case of the 6061 alloy/20%IF steel composite by eliminating production defects adjusting the matrix/second phase combination and conditions for cutting and plastic working.