Nd元素对强流脉冲电子束处理后Al-18Si-3Mg合金组织及性能的影响

Effect of Nd element on the structure and properties of Al-18Si-3Mg alloy treated by high-current pulsed electron beam

将添加稀土元素Nd后的Al-18Si-3Mg合金使用强流脉冲电子束(high-current pulsed electron beam,HCPEB)处理,以达到改善微观组织结构以及提升合金性能的目的.本实验利用扫描电子显微镜(scanning electron microscope,SEM),X射线衍射(X-ray diffraction,XRD),显微硬度计等一系列检测手段研究了添加Nd元素对Al-18Si-3Mg合金的组织结构及力学性能的影响.SEM结果表明,Nd元素能够起到细化初晶硅的作用,同时可有效消除熔坑结构.XRD结果表明,将Nd元素添加到铝硅合金中,没有相变产生,衍射峰随脉冲次数的增加将出现一定程度宽化和偏移现象.显微硬度测试结果表明,Nd元素的添加会导致硬度降低,同时通过控制脉冲次数的增加,合金显微硬度也会递增.另外,通过往复摩擦试验发现,Nd元素能够提升合金的耐磨性.稀土元素Nd的添加能够明显改善电子束处理形成的熔坑结构,并且使用电子束处理添加金属Mg和稀土Nd过共晶铝硅合金,能有效提升合金的机械性能.

The Al-18Si-3Mg alloy added with rare earth element Nd is treated by high-current pulsed electron beam(HCPEB),the purpose of improving microstructure and performance of alloy is achieved.In this experiment,a series of detection methods such as scanning electron microscope(SEM),X-ray diffraction(XRD),and microhardness test are used to study the effect of adding Nd element on the structure and mechanical properties of Al-18Si-3Mg alloy.SEM results show that Nd element can play the role of refining primary silicon,and can effectively eliminate the crater structure.XRD results show that when Nd element is added to the Al-Si alloy,no phase transition occurs,and the diffraction peak will show a certain degree of broadening and shifting with the increase of the pulses number.The microhardness test results show that the addition of Nd element will cause the hardness to decrease,and by controlling the increase of the pulse number,the microhardness of the alloy will also increase.In addition,through the reciprocating friction test,it was found that the Nd element can improve the wear resistance of the alloy.The addition of rare earth element Nd can significantly improve the crater structure formed by electron beam treatment,and the use of electron beam treatment to add metal magnesium and rare earth Nd hypereutectic aluminum-silicon alloy can effectively improve the mechanical properties of the alloy.