| 引用本文: | 于小健,吉卫喜,钱陈豪,刘书明,沈坚.Sr-Y复合变质对Al-7Si合金组织和性能的影响[J].材料科学与工艺,2021,29(3):49-56.DOI:10.11951/j.issn.1005-0299.20200031. |
| YU Xiaojian,JI Weixi,QIAN Chenhao,LIU Shuming,SHEN Jian.Effect of Sr-Y compound modification on the microstructure and mechanical properties of the Al-7Si alloy[J].Materials Science and Technology,2021,29(3):49-56.DOI:10.11951/j.issn.1005-0299.20200031. |
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| Sr-Y复合变质对Al-7Si合金组织和性能的影响 |
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于小健1,2,吉卫喜1,2,钱陈豪1,2,刘书明1,沈坚1
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(1.江南大学 机械工程学院,江苏 无锡 214122;2. 江苏省食品先进制造装备技术重点实验室,江苏 无锡 214122)
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| 摘要: |
| 为降低锶(Sr)变质Al-7Si合金熔体的含氢量和解决单添加稀土钇(Y)导致合金生产成本上升的问题,利用测氢仪、光学显微镜(OM)、扫描电镜(SEM)、WDW电子万能试验机和导电仪等测试手段,研究了Sr-Y复合变质对Al-7Si合金微观组织和力学性能的影响规律并对其作用机制进行了分析探讨。结果表明,Sr-Y复合变质不仅能降低合金熔体含氢量,还具有细化α-Al相和变质共晶Si的作用,同时能够提高合金力学性能和导电率。当添加0.05%Sr+0.15%Y复合变质剂时,熔体含氢量仅为0.12 mL/(100g Al),合金α-Al相高度细化为致密的等轴晶或椭圆晶,共晶Si从粗大的板片状和纤维状转变为细小的颗粒状。T6热处理后的合金抗拉强度、延伸率和导电率达到了296 MPa、10.2%和41.7% IACS,比单独Sr变质分别提高了10%、21%和7%,其拉伸断口表面呈现大量细小密集的韧窝,形状规则且分布均匀,属于韧性断裂。 |
| 关键词: Sr-Y 复合变质 Al-7Si 组织 性能 |
| DOI：10.11951/j.issn.1005-0299.20200031 |
| 分类号:TG146 |
| 文献标识码:A |
| 基金项目:国家自然科学基金项目(51905215)；江南大学大学生创新训练计划重点项目(2021110Z)；2019年度江南大学实验室管理专项研究课题(No.22). |
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| Effect of Sr-Y compound modification on the microstructure and mechanical properties of the Al-7Si alloy |
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YU Xiaojian1,2, JI Weixi1,2, QIAN Chenhao1,2, LIU Shuming1, SHEN Jian1
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(1. School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China; 2. Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment and Technology, Wuxi 214122, China; )
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| Abstract: |
| In order to reduce the hydrogen content of the Al-7Si alloy melt modified with Sr and lower the increasing production cost of alloy modified with single rare earth Y, the effect of Sr-Y compound modification on the microstructure and mechanical properties of the Al-7Si Alloy was investigated by the hydrogen gauge, optical microscopy (OM), scanning electron microscopy (SEM), WDW universal electronic testing machine and conductivity testing. Furthermore, the compound modification mechanism of refined microstructure and improved mechanical properties was discussed. It is found that the Sr-Y compound modification can not only effectively reduce the hydrogen content in alloy melt, but also refine the α-Al dendrite and modify the eutectic Si. Meanwhile, the Sr-Y compound modification can improve the mechanical properties and electrical conductivity of the Al-7Si alloy. When adding 0.05%Sr and 0.15%Y, the hydrogen content of the alloy melt is only 0.12 mL/(100 g Al), and the α-Al dendrite becomes into the dense equiaxed or elliptical crystals, and the eutectic Si changes from coarse plate and fiber to fine nanoparticles. The tensile strength, elongation and conductivity of the Sr-Y modified Al-7Si alloy are 296 MPa, 10.2% and 41.7% IACS, respectively, after T6 heat treatment. These values are improved by 10%, 21% and 7% compared with Sr modification accordingly. And the surface of tensile fracture illustrates abundent small and dense dimples with regular shape and uniform distribution, which belongs to ductile fracture in mechanism. |
| Key words: Sr-Y compound modification Al-7Si microstructure mechanical properties |
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