稀土Eu对铝/钢液-固复合双金属界面组织及力学性能的影响  

Interface Microstructure and Mechanical Properties of Al/steel Bimetal Prepared by Liquid-Solid Casting with Rare Earth Eu Addition

作　　者：乔永枫 毛丰 陈冲 魏世忠[2] 肖利强[2] 王宇[3] Qiao Yongfeng;Mao Feng;Chen Chong;Wei Shizhong;Xiao Liqiang;Wang Yu(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471003,China;National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,Henan University of Science and Technology,Luoyang 471003,China;School of Materials Science and Engineering,North University of China,Taiyuan 030051,China)

机构地区：[1]河南科技大学材料科学与工程学院,河南洛阳471003 [2]河南科技大学金属材料磨损控制与成型技术国家地方联合工程研究中心,河南洛阳471003 [3]中北大学材料科与工程学院,山西太原030051

出　　处：《稀有金属》2023年第9期1316-1323,共8页Chinese Journal of Rare Metals

基　　金：河南省重点研发与推广专项项目(192102210009);江苏省高端结构材料重点实验室开放基金项目(hsm103);中北大学金属凝固控制与精确成形山西省重点实验室开放基金项目(MSPM201904);国家自然科学基金项目(51701185)资助。

摘　　要：研究了稀土元素Eu对Al-7%Si/45^(#)钢液-固复合双金属界面组织的影响,并研究了加入Eu后对Al-7%Si/45^(#)钢双金属界面硬度和结合强度的影响。采用扫描电镜(SEM)对试样微观组织进行观察,采用能谱仪(EDS)等对试样进行成分分析,结果显示:加入稀土元素Eu后,Al-7%Si合金中共晶硅由粗大板片状转变为纤维状,同时金属间化合物层的厚度变薄;加入Eu并未改变界面金属间化合物种类,但是金属间化合物的形貌和尺寸发生改变,Fe_(2)Al_(5)相由舌状变平滑,τ1-(Al,Si)_(5)Fe_(3)相分布区域变窄,铝合金基体中的τ6-Al9Fe_(2)Si_(2)相由粗大针状变为细小针状。EDS面扫描和线扫描结果表明,稀土Eu元素可能抑制了Al和Fe元素的互扩散,阻碍了金属间化合物的凝固生长。稀土Eu元素加入明显提高了铝/钢双金属界面的硬度和结合强度。With the world attention to less energy consumption in the auto industry,aluminum alloys are regarded as potential materialsto replace steels considering the good conductivity,corrosion resistance and light weight.Al/steel bimetals with the advantage combination of both Al and Fe have currently become one of the research focuses.The liquid-solid casting process is a common method to produce Al/steel bimetal.However,there is always a challenge to obtain an excellent metallurgical interface for the bimetal casting due to the differences in physics and chemistry between aluminum alloys and steel.The hot-dipping of the steel by melt molten of aluminum alloy prior to liquid-solid casting process is thus utilized to form a continuous intermediate phase layer.The brittle intermetallics are not conducive to the bonding strength of Al/steel bimetal.The preceding study showed that the growth of intermetallic compounds,especially Fe_(2)Al_(5) phase had a great influence on mechanical properties.Therefore,this research on Al/steel bimetals aimed to control the growth of Fe_(2)Al_(5) phase and decrease the thickness of intermetallic compound layer.The interfacial microstructures and bonding strengths of Al-7%Si/45^(#)steel bimetal were studied by adding various amounts of rare earth Eu into aluminum alloy matrix in this study.Firstly,the surfaces of 45^(#)steel bars were polished to ensure basically same surface states.The further oil and rust removing were conducted by soaking into NaOH solution for 20 min,and HCl solution for 5 min at room temperature,respectively.In order to reduce the oxidation under high temperature,the steel bar was immersed into 5%NaCl(mass fraction)solution for 10 min at 80℃.Then,the hot-dipping of 45^(#)steel bars was carried out by soaking into Al-7%Si melts with different contents of rare earth Eu(0,0.05%,0.1% and 0.2%;mass fraction)for 5 min at 730℃.Finally,the steel bars after hot-dipping were put into a preheated metal mold at 400℃,and the melts with same composition used in hot-dipping we

关 键 词：铝/钢双金属 稀土元素 金属间化合物 液-固复合 界面 

分 类 号：TG146[一般工业技术—材料科学与工程]