Effect of copper addition on wear and corrosion behaviours of Mg2Si particle reinforced composites

The purpose of this study is to investigate the effect adding Cu has on the wear and corrosion properties of “in situ” Mg2Si particle reinforced Al–12Si–20Mg matrix composites, produced with help of the nucleation and growth of the reinforcement from the source matrix, in order to overcome the disadvantages of composites produced by externally reinforcing ceramic particles. Composites known as Al–12Si–20Mg–XCu were produced by adding Cu, at the rate of 1%, 2%, and 4%, to the Al–12Si–20Mg alloy in order to achieve this purpose. The microstructural characterisation, hardness, wear and corrosion properties of composites, produced using the casting method, were analysed. Dry environment wear experiments for investigated alloys were conducted using a pin-on-disc type wear device under different loads and at different sliding distances. The change in weight loss of the solution containing 30 g/l NaCl + 10 ml/l HCl, and the tafel extrapolation method were used to analyse corrosion behaviour. Results of microstructural characterisation concluded that as the amount of Cu added to the Al–12Si–20Mg alloy increased, the size and volume of the Mg2Si particle, formed within the matrix, decreased, and CuAl2 intermetallics formed within the matrix. Results of wear experiments concluded that adding Cu developed wear resistance under small loads; however, reduced wear resistance under high loads. According to results of corrosion experiment, corrosion resistance increased with the addition of Cu.

► The production of AlSiMg alloys reinforced with in situ Mg2Si particles with Cu addition.
► The effect of Cu addition on wear and corrosion properties of the investigated alloys.
► Adding Cu developed wear resistance under small loads and reduced under high loads.
► According to corrosion tests, corrosion resistance increased with the addition of Cu.