ECAP变形及半固态等温处理对Al-25%Si合金组织和性能的影响  

Effect of ECAP Deformation and Semi-Solid Isothermal Treatment on the Microstructure and Properties of Al-25%Si Alloy

作　　者：孙虎[1] 石羌瑾 王钰 周舟 王颖慧 SUN Hu;SHI Qiang-jin;WANG Yu;ZHOU Zhou;WANG Ying-hui(Department of Materials Engineering,Suqian University,Suqian 223800,Jiangsu,China)

机构地区：[1]宿迁学院材料工程系,江苏宿迁223800

出　　处：《铸造》2024年第2期187-193,共7页Foundry

基　　金：宿迁学院大学生创新创业训练项目(2023XSJ041Y);宿迁学院大学生创业创新培育项目(高硅铝合金缸套的新SIMA法制造工艺的研究);江苏省高等学校自然科学研究项目资助(21KJB430015)。

摘　　要：对铸态Al-25%Si合金进行等通道转角挤压(ECAP),并结合半固态等温处理技术,研究了ECAP挤压及半固态等温处理工艺参数对合金微观组织和室温拉伸性能的影响。利用光学显微镜观察分析微观组织,拉伸试验机测试室温拉伸性能,以及扫描电子显微镜分析断口形貌。研究结果表明,ECAP变形能够有效地细化Al-25%Si合金中的初生硅相,其平均直径由铸态的117.9μm降至31.9μm,同时形状因子也由0.12提升至0.40。ECAP后的常温力学性能也得到明显提升,其抗拉强度也由铸态的96 MPa提升至200 MPa,伸长率由1.04%提升至3.25%。在半固态加热过程中,初生硅的形状因子随等温温度的提升和时间的延长呈先增后降的趋势。在590℃保温10min,其形状因子最高为0.62。The as-cast Al-25% Si alloy was subjected to equal channel angular pressing(ECAP)in combination with a semi-solid isothermal treatment technique,and the effects of ECAP extrusion and semi-solid isothermal treatment process parameters on the microstructure and room-temperature tensile properties of the alloy were investigated.The microstructure was observed and analyzed by optical microscope,the room temperature tensile property was tested by tensile tester,and the fracture morphology was analyzed by scanning electron microscope.The results show that ECAP deformation can effectively refine the primary silicon phase in Al-25%Si alloy,and its average diameter is reduced from 117.9μm of as-cast to 31.9μm,while the shape factor is increased from 0.12 to 0.40.The room temperature mechanical properties are also significantly improved after ECAP,and the tensile strength is increased from 96 MPa of as-cast to 200 MPa.Furthermore,the elongation is increased from 1.04% to 3.25%.During the semi-solid heating process,the shape factor of primary silicon tends to increase and then decrease with the increase of isothermal temperature and time.The highest shape factor of 0.62 is obtained by holding at 590℃for 10 min.

关 键 词：等通道转角挤压 半固态等温处理 过共晶铝硅合金 初生硅 

分 类 号：TG146.21[一般工业技术—材料科学与工程]