半固态改性6061铝合金流变压铸试样组织及力学性能  

Microstructures and Mechanical Properties of Semi-solid Modified 6061 Aluminum Alloy Samples by Rheo-diecasting

作　　者：张荣晟 毛卫民[1] 李乃拥 Zhang Rongsheng;Mao Weimin;Li Naiyong(School of Materials Science and Engineering,University of Science and Technology,Beijing 100083)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《特种铸造及有色合金》2024年第4期516-520,共5页Special Casting & Nonferrous Alloys

基　　金：国家自然科学基金资助项目(51771032)。

摘　　要：采用石墨质蛇形通道浇注复合流变压铸工艺进行半固态改性6061铝合金流变压铸成形。对比分析了传统液态压铸和流变压铸的改性6061铝合金试样的显微组织;研究了Si含量对半固态改性6061铝合金流变压铸试样组织及力学性能的影响。结果表明,相比于传统液态压铸,半固态改性6061铝合金流变压铸试样组织中的初生α-Al晶粒明显细化和球化,由粗大的枝晶演变为细小的球状晶或近球状晶。增加Si含量可以有效细化试样组织中的初生α-Al晶粒,并提升流变压铸试样的力学性能,当Si含量由0.6%增加至2.6%时,初生α-Al的平均晶粒直径由58μm左右逐渐减小至31μm左右,抗拉强度由(107±4)MPa逐渐增加至(209±14)MPa,伸长率由2.2%±0.3%逐渐增加至5.5%±0.5%。The rheological high pressure die casting process(Rheo-HPDC)samples of semi-solid modified 6061 aluminum alloy were prepared by graphite serpentine channel pouring process(SCP)and Rheo-HPDC.The microstructure of 6061 aluminum alloy formed by traditional die casting and rheo-diecasting was analyzed comparatively.The effects of Si content on the microstructure and mechanical properties of Rheo-HPDC samples of semi-solid modified 6061 aluminum alloys were investigated.The results indicate that compared with the traditional die casting,the microstructure of primaryα-Al grains in the Rheo-HPDC samples of semi-solid modified 6061 aluminum alloys are significantly improved and refined,which is evolved from coarse dendrites to fine spherical or subspherical crystals.The primaryα-Al grains can be effectively refined and the mechanical properties can be improved with increasing in the Si content.When Si content is increased from 0.6%to 2.6%,the average grain diameter of primaryα-Al grains is decreased approximately from 58μm to 31μm,the tensile strength is increased from(107±4)MPa to(209±14)MPa,and elongation is increased from 2.2%±0.3%to 5.5%±0.5%.

关 键 词：6061铝合金 半固态流变压铸 显微组织 力学性能 

分 类 号：TG146.2[一般工业技术—材料科学与工程]