Sr、Fe、Cu对压铸A356合金性能的影响

Influence of Sr、Fe、Cu on Properties of Die Casting A356 Aluminum Alloys

采用光学显微镜、扫描电镜对试样微观组织进行了形貌观察,采用X射线衍射分析仪、能谱仪分别对试样进行了相分析与相成分分析,研究了Sr、Fe、Cu对压铸Al-Si系合金的性能和微观组织的影响。结果表明,Sr对压铸铝合金中的Si有一定的变质效果,但对性能的提升效果不明显。Fe含量达到0.8%时,组织中开始出现针状β-Fe相和初生α-Fe相。Cu可以提高合金的强度,但剧烈降低合金塑性,Cu含量较高时,组织中会出现N-Al7Cu2Fe相和W-Al2Si4Mg5Cu4相。

Effects of Sr.Fe and Cu on properties of die casting aluminum alloys were investigated by opti- cal microscope（OM） and scanning electric microscope（SEM） , X-ray diffraction（XRD）and energy dis- persive X-ray （EDS）, respectively. The results reveal that Sr exhibits modification effect on die casting aluminum alloys to some extent, however, it takes little increase of strength. When the Fe content rea- ches 0.8 %, needle-like fl-Fe phase and primary a-Fe phase can be observed in the microstructure of the alloy. Cu can improve the strength of the aluminum alloys. However, it will reduce the ductility sharp- ly. With a higher Cu content, N-A17Cu2Fe and W-A12Si4Mg5Cu4 can be precipitated from the micro- structure of the alloy.