Modification And Dynamic Impact Mechanical Properties Of High Strength Aluminum Alloys For Vehicles

In recent years,aluminum alloy and its composite materials have been widely used in automobile body structure due to their excellent properties such as high strength,low density and wear resistance.This paper examines the dynamic mechanical properties and corrosion resistance of Series Ⅵ（6061）and Series Ⅶ（7075）aluminium alloys and SiC particle-reinforced aluminium matrix composites for automotive applications,as well as the wear properties of 6061 and 7075 aluminium alloys.The dynamic mechanical properties of 6061 aluminum alloy,7075 aluminum alloy and SiC particle reinforced 6061 aluminum alloy（6vol.%SiCp/6061Al）composites under different strain rates were investigated by using hopkinson pressure bar device.The results show that the flow stress of 6061 aluminum alloy increases gradually with the increase of strain rate when the strain rate is 250s^-1～500s^-1,indicating that 6061 aluminum alloy has high elongation and good ductility,and has a certain strain rate effect;The flow stress,elastic limit and yield strength of 7075 aluminum alloy also increase with the increase of strain rate,and the unloading strain increases with the increase of strain rate,indicating that 7075 aluminum alloy has a relatively significant work hardening behavior;With the increase of strain rate,the flow stress of 6vol.%SiCp/6061Al composite does not change obviously,indicating that the flow stress of 6Vol.%SiCp/6061Al composite is not sensitive to the strain rate in this range.The phenomenon of"dynamic strain aging"occurs during impact compression,the dynamic properties of 6vol.%SiCp/6061Al composite are better than that of 6061 aluminum alloy.The friction and wear properties of 6061 and 7075 aluminium alloys under different loads were investigated using the MPX-3G pin and disc friction and wear tester,and the wear surfaces of the materials were observed and analysed using scanning electron microscopy.The results show that the wear mass loss of both 6061 and 7075 aluminium alloys increases with wear time,with the coefficient of friction and wear mass loss of7075 aluminium alloy being lower than that of 6061 aluminium alloy,indicating that 7075aluminium alloy has better wear resistance.Surface corrosion behaviour of 6061 and 7075 aluminium alloys and 6vol.%SiCp/6061Al composites observed by simulated seawater experiments,the results show that the corrosion resistance of the 6061 aluminium alloy composites is significantly enhanced by the addition of SiC particles,and the corrosion resistance of the 6vol.%SiCp/6061Al composites is better.The above research results are expected to provide an experimental basis for the practical application of aluminium alloy materials in the lightweighting of automotive structures.Figure[42]table[6]reference[99]...