摘要
通过在Al-Si合金中加入Sc和Ti元素,经过180℃×2 h或220℃×3 h短时时效热处理来调控铸造Al-Si合金的导热、热膨胀及力学性能。采用光学显微镜(OM)、扫描电镜(SEM)、X射线能谱仪(EDS)等方法观察合金元素及短时时效热处理对铸造Al-Si合金组织演化的影响,并建立微观组织与材料导热系数、热膨胀系数和力学性能之间的关系。结果表明,Si含量的增加能促进粗大初生Si相的析出,弱化Al-Si合金的导热和力学性能,抑制材料的热膨胀程度。Sc或Ti的加入能抑制初生Si相的粗化,细化次生Si相,提升Al-12Si合金的抗拉强度;同时,可以降低材料的热膨胀系数。短时时效热处理可缓解材料元素偏聚现象,显著提升Al-Si合金导热系数,但会降低铸造Al-Si-(Sc,Ti)合金的导热系数。
The thermal conductivity,thermal expansion and mechanical properties of casting Al-Si alloys were regulated by introducing Sc and Ti elements into Al-Si alloys,combining with short-time aging heat treatment at 180℃for 2 h or 220℃for 3 h.Effects of alloying elements and short-time aging treatment on the microstructure evolution of casting Al-Si alloy were investigated by optical microscope(OM),scanning electron microscope(SEM),X-ray energy dispersive spectrometer(EDS),and the relationship between microstructure and thermal conductivity,thermal expansion as well as mechanical properties of the alloy was established.The results indicate that the increase of Si addition promotes the precipitation of the coarse primary Si phase,thereby weakening the thermal conductivity and mechanical properties of the Al-Si alloy,while effectively inhibiting the thermal expansion of the alloy.The addition of Sc or Ti can inhibit the coarsening of primary Si phase and refine secondary Si phase,thus improving the tensile strength of Al-12Si alloy,which can also reduce the thermal expansion coefficient of Al-Si alloy.Short-time aging treatment can alleviate the segregation of elements,significantly improving the thermal coefficient of Al-Si alloys,and reducing the thermal coefficient of Al-Si-(Sc,Ti)alloys.
作者
杨湘杰
郭洪民
康跃华
周志明
杨浩坤
Yang Xiangjie;Guo Hongmin;Kang Yuehua;Zhou Zhimin;Yang Haokun(School of Mechanical Engineering,Nanchang University;College of Materials Science and Engineering,Nanchang University;Institute of New Materials,Guangdong Academy of Sciences;College of Materials Science and Technology,Chongqing University of Technology;Smart Manufacturing Division,Hong Kong Productivity Council,china)
出处
《特种铸造及有色合金》
CAS
北大核心
2023年第5期577-582,共6页
Special Casting & Nonferrous Alloys
基金
国家自然科学基金资助项目(50474007)
江西省重大研发计划资助项目(20161ACE50021)
重庆市技术创新与应用产业类重点资助项目(cstc2019jscx-fxydX0072)
重庆市英才计划资助项目(2020RC22)
香港生产力促进局Commercial Research&Development(CRD)(10010788)。
