Impact of Chromium Addition on the UTS and ETF of Aluminium Alloy AA6061 Chips Based Composite

Abstract

Aluminium matrix composite has been increasingly developed due to the impressive performances demonstrated, mechanically and physically. The related properties were enhanced with the addition of reinforcing materials and this tailor-made composite can be used in the area of automotive, aerospace and military. In this study, the matrix composite was developed directly from aluminium chips without remelting through a series of hot press forging operations. This process involved heating the aluminium chip mixtures with 1 to 8 wt% chromium content above the recrystallization temperature. Then, the uniaxial force was subsequently applied onto the composite. For performance measures, the hot pressed composites were tested for the ultimate tensile strength (UTS) and elongation to failure (ETF). The composite with 2 wt % of chromium exhibits significant improvement compared to other samples, with the UTS and ETF reached to 215.37 MPa and 30.65% respectively. This sample exceeds the minimum stress and strain of stock aluminium AA6061-T4. Furthermore, the addition of chromium beyond 2 wt % would generally cause reduction of the mechanical properties of the composite.