Si含量对Al-Si-Cu-Ni-Mg合金组织和性能的影响OACSTPCD

Different Si content alloys were prepared by stir casting process,aiming to reveal the effect of Si content on microstructure,mechanical properties and wear resistance of Al-Si-Cu-Ni-Mg.The results showed that with the increase of Si content,the aspect ratio and average length of eutectic Si firstly increase and then decrease,and the aspect ratio and average length of the alloy with Si content of 16 wt.％were the largest,which were 8.8 and 24.1 μm,respectively.After 520 ℃/6 h solid solution+180 ℃/5 h aging treatment,the morphology of the eutectic Si was changed from fibrous to spherical,and the angles of the incipient Si became smooth and rounded.Eutectic Si aspect ratio and average length of the alloy decreased significantly,keeping the same trend as that of the cast alloy,and the aspect ratio and average length of the alloy with Si content of 16wt.％were 3.5 and 12.4 μm,respectively,and there was no significant change in the size of incipient Si.The tensile properties of the as-cast alloys gradually decreased and the hardness gradually increased with increasing Si content.After T6 heat treatment,the tensile properties and hardness of the alloys were significantly improved,maintaining the same trend as the cast alloys.With the increase of Si content,the wear loss of the alloy decreases and the wear resistance is improved,the alloy with Si content of 16 wt.％has the least wear loss and the best wear resistance;the wear resistance of the alloy decreases when the Si content continues to increase.