Influence Of Rapid Solidification Rare Earth On Microstructure And Properties Of High Magnesium Aluminum Alloys

Al-12Mg alloy is a special kind of high magnesium alloy, with high corrosion resistance, strength, machinability, which has been used in national defense industry for a long time. With development of scientific and technological development, there is a higher demand for such conventional military materials. It is necessary to use unconventional means to obtain a superior material to meet the needs of industry.The addition of trace mircoalloying element to aluminum alloys is one of those effective means to improve the synthesis properties of the aluminum alloys. Rapidly solidified alloy and microalloying are used into cast aluminum alloy flexibly in this article. By changing the contents of minor elements by means of hardness testing, tensile properties measurement, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) , optical microscopy (OM).Effect of minor addition of Zirconium and Erbium respectively or meanwhile on microstructure and properties of Al-12Mg alloy were investigated. Rapid-solidified Al-Re(Ce,Y) alloy are put into Al-12Mg-0.2Zr-0.2Er.Microstructure of the Al-12Mg-0.2Zr-0.2Er-Re(Ce,Y) alloy was observed by using SEM,and properties was investigated.The addition of minor Zirconium and Erbium respectively or meanwhile can lead to increase tensile strength and refine the microstructure of Al-Mg alloy. Tensile strength is improved by 18% with adding 0.2%Zr respectively and by 34% with meanwhile 0.2% Er and 0.2%Zr. The refining effet of Al-Mg alloy with adding meanwhile are the best.The results show that properties of Al-Mg alloy with rapid-solidified alloy are much better than traditional alloys'. Eutecticβphase changing from net to small island or rod disperses in the matrix. And new quadrate and fibrous phase appears around grain boundary.Mechanical property of Al-Mg alloy with adding rapid-solidified alloy is much better than Al-Mg alloy without rapid-solidified alloy. Tensile strength of Al-12 Mg-0.2Zr-0.2Er is 258Mpa. Tensile strength shows a trend of first increase and then decrease. Tensile strength is imprived by 23% and 10% with 0.8% Ce content addition.Meanwhile, tensile strength is imprived by 13% and 28% respectively with 0.6% Y content addition. This is mainly due to the rapid solidification of the state master alloy is micro-and nano-crystalline amorphous with high free energy,especially structuralHeredity of rapid-solidified alloy. Its unique fine characteristic is inherited into Al-Mg-Zr-Er alloy. When rare earth content is more than critical value, mechanical properties emerge significantly lower.Adding rapid solidified Al-RE(Ce,Y) alloy, fracture surface is formed by a number of dimples,brittle fracture disappers and a ductile fracture characteristicshows.