An Approach for Recycling of Aluminum Machining Chips and Characterizing Its Castings

Abstract

The aim of this research was to explore productive method of recycling aluminum machining chips accumulated in machine shops. The physical nature and condition of aluminum chips usually induce recycling difficulties. As a result, it is causing environmental pollution and wastage of aluminum chip resources. In this study, two recycling approaches were experimentally investigated. The first was direct melting trial of chips and the second was blending chips with initially melted aluminum alloy scrap and then remelting it for further chip blending. The former was found completely unsuccessful due to 100% chip oxidation. But, the blending method was found successful for mass recycling. To validate the method, experimental investigations were carried out on metal yield, density, relative density, hardness, tensile strength, compressive strength, and surface roughness. For the stated tests, recorded results were 94.33%, 2.61 gm/cm3, 96.67%, 53.7 HV, 173.33 MPa, 402.62 MPa, and 1.35 μm, respectively. The chemical composition analysis says that class of the cast samples is aluminum alloy 404415s with 8.98% Si. Moreover, the XRD analysis reveals a perfectly crystalline structure. The 94.33% metal yield was an important productivity indicator. Furthermore, samples were machined to check their applicability and presence of visible porosity or crack internally and were found as desired. Therefore, this blending and remelting approach was strongly recommended for recycling of aluminum machining chips and it can protect the environment against pollution.