Properties of upgradable recycled Al–Mg–Si alloys fabricated from machined chips via mechanical milling and spark plasma sintering

Abstract

Machined chips of Al–Mg–Si alloys produced by turning were mechanically milled (MM) using a vibration type of ball mill, and MMed powders were consolidated into bulk materials by the spark plasma sintering (SPS) technique. Changes in hardness and solid-state reactions of the MMed powder and bulk materials have been investigated by hardness measurements and an X-ray diffraction (XRD). A high level of strain was introduced into machined chips by turning before MM process. Further strain can be introduced into machined chips by MM process. The value of hardness for obtained MMed powders and bulk materials was more than 160 HV and 250 HV, respectively. The solid-state reaction between the MMed powder and process control agent (PCA) during SPS process after MM process was observed to form Al₄C₃. Properties of machined chips were enhanced by strain induced through plastic deformation via turning and MM process together with solid state reaction. The combination of MM-SPS process is beneficial process for producing upgradable recycled bulk materials.