The Content Of Mn Influences On Metallurgical Microstructure And Mechanical Property Of Al-mn Alloy

Al-Mn alloy is widely used in packaging materials, heat exchange materials, photosensitive materials, decoration materials, welding materials and the processing of forming a variety of needs and higher corrosion resistance than pure Al, because of it's low density, corrosion resistance, good thermal conductivity property.At present, our country just studied on Mn between 1.0 % and 1.6% and Al-10Mn alloy, but with higher content of Mn research less, there is no research between 3% and 5% of Al-Mn alloy. In this study, the way of artificial mixing casting of between 1% and 5% were prepared with different content of Mn of the Al-Mn alloy. And then we get the metallurgical microstructure specimens, standard v from machine tools, tensile samples from the lathe and milling machines, metallurgical organization from LED-1430VP (SEM), the impact of the toughness from JB30A type test;HBS hardness from HR-150, the loading of 62.5kg, pressure head's diameter is 5㎜。This research studies microstructure, hardness, impact properties with the content of Mn between 1% and 5% of Al-Mn alloy, and tensile properties with the content of Mn between 1% and 3%, the mechanical property of materials is found after studying.Al-Mn alloy is prepared successfully by stirring casting, the experimental results show that:①metallurgical microstructure: the second phase of the shape changes from thin to thick, from long to short, it's heads vary from round to square as the increase of the content of Mn, but the second phase is not closely connected with the matrix, and also it has a crack.②hardness: cast hardness increases as the content of Mn increases, the annealed hardness is essentially the same, there is no significant increase after artificial aging.③impact property: the impact toughness decreased with the increase of the content of Mn, fracture with obvious dimples and river pattern from the stress fracture to brittle fracture,④tensile property: shrinkage and elongation decreased With the increase of Mn content, tensile strength increased first, and then decreased This article was prepared by artificial stirring casting high content of Mn of Al-Mn alloy, mechanical properties can basically meet the requirements.