论文部分内容阅读
研究了Sb含量对A356合金组织和力学性能的影响,并利用热分析、液淬试验对Sb变质机理进行了分析。结果表明,Sb变质A356合金的最佳含量为0.4%,此时共晶Si由粗大的板条状变为细小的纤维状。由于Sb的变质作用,A356合金的力学性能尤其是伸长率得以显著提高,合金的铸态伸长率最高可达11.3%,相比于未变质合金提高了79%。结果表明,Sb能够有效地降低共晶组织的形核温度,提高其形核过冷度,降低共晶组织的形核率。
The effect of Sb content on microstructure and mechanical properties of A356 alloy was studied. The mechanism of Sb modification was analyzed by thermal analysis and liquid quenching test. The results show that the optimum content of Sb-modified A356 alloy is 0.4%. At this time, eutectic Si changes from coarse lath to fine fiber. Due to the deterioration of Sb, the mechanical properties, especially elongation, of A356 alloy can be significantly improved. The as-cast elongation of the alloy reaches up to 11.3%, which is 79% higher than that of the unmodified alloy. The results show that Sb can effectively reduce the nucleation temperature of the eutectic structure, increase the undercooling and decrease the nucleation rate of the eutectic structure.