摘要
利用凝固过程温度-时间曲线、偏光显微镜、扫描电子显微镜、电子背散射衍射技术、透射电子显微镜和能谱仪研究了重力砂型铸造条件下锑(Sb)对亚共晶Al-Si合金晶粒和共晶Si的影响。结果表明,Al-7Si合金添加Sb后,初生α-Al晶粒和共晶Si的形核温度均降低,初生α-Al晶粒形核更困难,平均粒径由319μm增至353μm。Sb变质共晶Si的机理是使共晶Si形核温度降低,Si在α-Al中的固溶度减小,化学势增大,Si原子从α-Al中排出的速度增大,共晶Si生长速度加快,最终共晶Si变短变窄。Sb并非通过作用在共晶Si的形核核心和孪晶上发挥变质作用。
The effects of antimony(Sb) on grains and eutectic Si of hypoeutectic Al-Si alloy under gravity sand casting conditions were investigated by solidification temperature-time curves,polarized light microscope(PLM),scanning electron microscope(SEM),electron backscattered diffraction(EBSD),transmission electron microscope(TEM),and energy disperse spectroscope(EDS).The results show that the addition of Sb to the Al-7Si alloy results in a decrease in the nucleation temperature of primary α-Al grains and eutectic Si.The nucleation of primary α-Al grains becomes more difficult,and their average size increases from 319 μm to 353 μm.The mechanism of Sb modifying eutectic Si is that with Sb addition,the nucleation temperature of eutectic Si decreases,the solid solubility of Si in α-Al decreases,the chemical potential increases,the velocity of Si atoms discharging from α-Al increases,the growth rate of eutectic Si increases,and finally the eutectic Si becomes shorter and narrower.Sb does not play its role of modification by acting on the nucleation cores and twins of eutectic Si.
作者
毛郭灵
蒲博闻
王根全
杨晨帆
周海涛
何晓东
MAO Guo-ling;PU Bo-wen;WANG Gen-quan;YANG Chen-fan;ZHOU Hai-tao;HE Xiao-dong(China North Engine Research Institute(Tianjin),Tianjin 300400,China)
出处
《稀有金属与硬质合金》
CAS
CSCD
北大核心
2023年第4期83-87,共5页
Rare Metals and Cemented Carbides
