Effect of multiple remelting on selected properties of dispersed reinforced aluminum matrix composite

In the investigations, described in the paper, the analysis of conditions for recycling materials used in car vehicles is presented. This problem is related with the requirement of UE regarding recovery of product, material or energy -(the Instruction EU No. 2000/53/WE, 18.09.2000). This research is aimed on the investigation of the recycling treatment on properties of commercial aluminum matrix composite reinforced with SiC particles, as a candidate for prototype production of modern brake discs and rotors for automotive applications. Repeated remelting of F3S.10S composite (A359 aluminum alloy reinforced with 10% by vol. of SiC particulates) has been performed. Multiple remelting of composite followed by its gravity casting to the cast iron die does not cause any important changes in composite microstructure noticeable under optical microscopy magnifications. The results of investigation of physical and mechanical properties show that recycling treatment, characterized by the number of remelts followed by the same casting procedure, causes the noticeable change of all properties of composite material. The results demonstrate a continuous decrease in utility properties of composite material with increase of the number of remelting operations, showing tolerable reduced strength characteristics after 9th remelting. Nevertheless, in the face of occasional increase in a given property from one remelt to another, these preliminary investigations suggest the possibility to improve recycling process by proper selection of liquid metal treatment and subsequent casting procedure.