Effects of mechanical vibration on the physical,metallurgical and mechanical properties of cast A308(LM21)aluminum alloy  

作　　者：Siddharth Yadav S.P.Tewari J.K.Singh S.C.Ram 

机构地区：[1]Department of Mechanical Engineering,Indian Institute of Technology(BHU),Varanasi 221005,India [2]Department of Metallurgical Engineering,Indian Institute of Technology(BHU),Varanasi 221005,India

出　　处：《International Journal of Minerals,Metallurgy and Materials》2022年第6期1206-1215,共10页矿物冶金与材料学报（英文版）

摘　　要：This study investigated the microstructure,physical,and mechanical properties of die-cast A308 alloy subjected to mechanical vibration during solidification.Different frequencies(0,20,30,40,and 50 Hz)at constant amplitude(31μm)were employed using a power amplifier as the power input device.X-ray diffraction,optical microscopy,and scanning electron microscopy were used to examine the morphological changes in the cast samples under stationary and vibratory conditions.Metallurgical features of the castings were evaluated using Image J software.The average values of metallurgical features,including primaryα-Al grain size,dendrite arm spacing,average area of eutectic silicon,aspect ratio,and percentage porosity,reduced by 34%,59%,56%,22%,and 62%,respectively,at 30 Hz frequency compared with stationary casting.Mechanical tests of the cast samples showed that the yield strength(YS),ultimate tensile strength(UTS),percentage elongation(%EL),and microhardness(HV)increased by 8%,13%,17%,and 16%,respectively,at 30 Hz frequency compared with stationary casting.The fractured surface of the tensile specimens exhibited mixed-mode fracture behavior because of brittle facets,cleavage facets,ductile tearing,and dimple morphologies.The presence of small dimples showed that plastic deformation occurred before fracture.

关 键 词：mechanical vibration MICROSTRUCTURES MICROHARDNESS tensile strength FRACTOGRAPHY 

分 类 号：TG146.21[一般工业技术—材料科学与工程]