熔体超声处理对Al-Si合金组织和力学性能的影响

Influence of Ultrasonic Melt Treatment on Microstructure and Mechanical Properties of Al-Si Alloy

利用超声处理器对Al-Si合金熔体进行处理,研究超声功率对Al-12Si-4Cu-3Ni-Mg合金显微组织与力学性能的影响,并分析其作用机理。结果表明:合金熔体超声处理后,铸态组织中初晶硅相由粗大多边形变成细小且均匀分散的颗粒,α-Al细小圆整,富铁相由粗大的十字状转变为细小的块状;当熔体处理温度720℃、超声功率1.5k W、处理时间2 min时,合金的350℃抗拉强度和伸长率分别为110 MPa和5%,是未经超声处理的1.33倍和1.67倍;随超声功率的增加,初晶硅尺寸逐渐减少并呈线性关系;超声处理提高了Al-Si合金熔体凝固过程中初晶相、共晶相的析出温度,细化了合金组织。

Al-Si alloy melt was treated by ultrasonic processor.The effects of ultrasonic power on the microstructure and mechanical properties of Al-12 Si-4 Cu-3 Ni-Mg alloy were studied,and the mechanism was analyzed.The results indicate that after ultrasonic treatment of the alloy melt,the primary silicon phase in the as-cast microstructure changes from coarse polygon to fine and uniformly dispersed particles,α-Al is fine and round,and the iron-rich phase changes from coarse cross shape to fine block.When the melt treatment temperature is 720℃,the ultrasonic power is 1.5 kW,and the treatment time is 2 min,the tensile strength and elongation of 350℃are 110 MPa and 5%,respectively,which are 1.33 and 1.67 times of those without ultrasonic treatment.With the increase of ultrasonic power,the size of primary silicon decreases gradually and shows a linear relationship.Ultrasonic treatment increases the precipitation temperature of the primary and eutectic phases during the solidification of Al-Si alloy melt and the alloy structure is refined.