摘要
以砂型铸造Al-7Si-Mg合金为研究对象,研究了Sr含量对Al-7Si-Mg合金铸态组织和力学性能的影响。结果表明,添加Sr变质后,铸态Al-7Si-Mg合金的晶粒粗化,一次柱状晶生长明显。Sr变质Al-7Si-Mg合金中共晶Si形貌由针状或层片状组织向细化纤维状转变。当用0.06%的Sr变质时产生过变质现象,界面处Al-Si-Sr三元化合物逐渐增多,并产生富集。当Sr的含量为0.04%时,Al-7Si-Mg合金的抗拉强度和伸长率均达到最大,比未变质合金的抗拉强度和伸长率分别提高了8.4MPa、68.4%。
Effects of Sr addition on the microstrueture and mechanical properties of the as-cast Al-TSi-Mg alloy have been investigated. The results indicate that the grain size is increased with the addition of Sr element, and the morphology of primary dendrite is transformed to columnar structure. With the in- crease of Sr addition, the morphology of eutectic Si is changed from coarse planar or acicular structure to fine fibrous one. Meanwhile, the Al-Si-Sr ternary phases can be observed in the alloy with gathered a- long the interface of eutectic and primary a-Al with 0.06% Sr. With 0.04% Sr addition, the tensile strength and elongation of the as-cast Al-TSi-Mg alloy reach a desirable value, increased by 8.4 MPa and by 68.4%, respectively, compared with those of the unmodified alloy.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2013年第8期691-695,共5页
Special Casting & Nonferrous Alloys
基金
国家重点基础研究发展计划(973计划)资助项目(2011CB606302)
国家支撑课题资助项目(2011BAE21B01)
