Impact of ultrasonic power on liquid fraction,microstructure and physical characteristics of A356 alloy molded through cooling slope  

超声功率对冷却斜槽模压A356合金液相分数、微观组织及物理特性的影响

作　　者：Pabak MOHAPATRA Nirmal Kumar KUND 

机构地区：[1]Department of Production Engineering,VSS University of Technology,Burla 768018,India

出　　处：《Journal of Central South University》2022年第4期1098-1106,共9页中南大学学报（英文版）

基　　金：Project(SAP-9162)supported by the Ministry of Mines,Technology Information,Forecasting and Assessment Council(TIFAC),Department of Science and Technology(DST),India。

摘　　要：This study involves A356 alloy molded through ultrasonically vibrated cooling slope.The slope alongside ultrasonic power enables indispensable shear for engendering slurry from which the semisolid cast/heat treated billets got produced.An examination demonstrates ultrasonically vibrated cooling slope influencing the liquid fraction/microstructure/physical characteristics of stated billets.The investigation encompasses five diverse ultrasonic powers(0,75,150,200,250 W).The ultrasonic power of 150 W delivers finest/rounded microstructure with enhanced physical characteristics.Microstructural modifications reason physical transformations because of grain refinement and grain boundary/Hall-Petch strengthening.A smaller grain size reasons a higher strength/shape factor and an increased homogeneity reasons a higher ductility.Microstructural characteristics get improved by reheating.It is owing to coalescence throughout temperature homogenization.The physical characteristics is improved by reheating because of a reduced porosity and enhanced dissolution besides augmented homogeneity.A direct comparison remains impossible owing to unavailability of researches on ultrasonically vibrated cooling slope.本文采用超声振动冷却斜槽对A356合金进行成型。超声振动冷却斜槽能剪切产生半固态铸造/热处理坯料的浆料,研究了5种不同的超声功率(0、75、150、200、250 W)下坯料的液相分数、显微组织、物理特性。当超声功率为150 W时,合金的微观组织更精细、圆整,物理特性更强。由于晶粒细化和晶界/Hall-Petch强化导致微观结构改变,从而导致物理性能改变。晶粒尺寸越小,强度/形状因子越高;晶粒均匀性越高,塑性越好。由于温度均匀化的合并作用,再加热改善了合金的微观组织;随着孔隙度的降低和溶解的增强以及均匀性的增强,在再加热过程中材料的物理性能得到改善。

关 键 词：ultrasonic power MICROSTRUCTURE physical characteristics semisolid cast A356 alloy cooling slope 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG663[金属学及工艺—金属材料]