摘要
分别使用普通硅砂和铬铁矿砂浇注铝合金阶梯试样,分析其试棒的抗拉强度、屈服强度、伸长率以及硬度,分析其金相组织,测其晶粒度和二次枝晶间距并进行对比。试验表明,采用铬铁矿砂铸造,明显提高铸件的抗拉强度;伸长率在壁较薄处也有较大提升,而在壁厚较厚处则优势下降;晶粒细化效果显著,晶粒度和二次枝晶间距优于普通硅砂铸件,冷却速度敏感性小于普通硅砂铸件。因此铬铁矿砂更适合于作为强度要求高的铸件,但是由于其强烈的激冷效果使得金属液流动性变差,因此不适合做形状复杂铸件的造型材料,加之价格昂贵,其使用受到限制。
Aluminum alloy multi-step samples were prepared in common sand mold and in chromite sand mold,and the tensile strength,yield strength,elongation and hardness of the prepared samples were examined.Meanwhile,the microstructure of the samples prepared was observed,and the grains size and DAS（secondary dendrite arm space） were comparatively analyzed.The results show that the sample prepared in chromite sand mold is obviously improved in tensile strength and is increased in elongation at the thin-walled location,meanwhile,it is superior to those in common sand mol in grains size and DAS,however,it is lower than that in common sand mold in cooling rate sensitivity.The chromite sand is more suitable for preparing the parts with high strength,however,it is not suitable for the mold materials for the complicated castings due to its intense cooling rate resulting in the low fluidity of liquid metal.So it was limited in application scope.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2011年第9期859-862,共4页
Special Casting & Nonferrous Alloys
基金
科技部科技型中小企业技术创新基金项目(09C26279200863)
江苏大学"科技创新团队"资助
