超声振动对活塞用近共晶铝硅合金硅相形貌及生长机制的影响  

Effect of Ultrasonic Vibration on Morphology and Growth Mechanism of Silicon Phase in Near-Eutectic Al-Si Alloy for Piston

作　　者：董雄博 郭永春[1] 夏峰[1] 李建平[1] DONG Xiongbo, GUO Yongchun, XIA Feng, LI Jianping(School of Materials and Chemical Engineering, Xi＇an Technological University, Xi＇an 710021, Chin)

机构地区：[1]西安工业大学材料与化工学院

出　　处：《热加工工艺》2018年第5期68-72,共5页Hot Working Technology

基　　金：装备预研领域基金重点项目资助(61409220103);陕西省创新人才推进计划-科技创新团队项目(2017KCT-05);陕西省教育厅重点科学研究计划项目(16JS044)

摘　　要：采用热分析法获得了活塞用合金Al-11.5Si-4Cu-Mg-2.6Ni-0.45Fe（质量分数）初生硅、共晶硅的析出长大温度,通过液淬法得到了合金凝固瞬间组织。研究了超声振动对合金初生硅、共晶硅形貌的影响,并对超声振动下初生硅、共晶硅的形核长大机制进行了简单分析。结果表明：在合金液相线以下施加超声振动可以减小初生硅的尺寸,促进初生硅的析出,改善初生硅的形貌并减小初生硅的长大速率;超声振动也可以促进共晶硅的析出,使共晶硅由长针状转化为短棒状,且超声振动后共晶硅基本在α-Al枝晶周围形核。The temperatures of precipitation and growth of primary silicon and eutectic silicon of Al-ll.5Si-4Cu- Mg-2Ni-0.45Fe （mass fraction） alloy for the piston were obtained by using thermal analysis method. The instant solidification microstructure of the alloy was obtained by liquid quenching method. The effects of ultrasonic vibration on the morphologies of primary silicon and eutectic silicon in the alloy were studied. The nucleation and growth mechanism of primary silicon and eutectic silicon under ultrasonic vibration were simply analyzed. The results show that applying ultrasonic vibration below the liquid temperature of the alloy can reduce the size of the primary silicon, promote the precipitation of primary silicon, improve the morphology of primary silicon and reduce the growth rate of primary silicon. Ultrasonic vibration can also promote the precipitation of eutectic silicon, make eutectic silicon transform from long needle-shaped into a short rod-shaped, and the eutectic silicon after ultrasonic vibration nucleates around the α-Al dendrites.

关 键 词：铝硅合金 超声振动 硅相 凝固 

分 类 号：TG292[金属学及工艺—铸造] TG146.21[一般工业技术—材料科学与工程]