【作者】 李拥军；

【导师】 程和法；

【作者基本信息】 合肥工业大学 ， 材料加工工程， 2007， 硕士

【摘要】 本文采用高能超声波搅拌法制备半固态Al-5％Cu合金，研究了合金的凝固组织随超声波搅拌工艺参数变化的规律；并且结合渗流法制备高体分数SiC_p／ZL101预制块和高能超声波半固态搅拌的方法制备SiC_p／ZL101复合材料，探讨了用这种工艺制备金属基复合材料，以及其组织和性能的控制方法。首先，采用超声波搅拌法制备半固态Al-5％Cu合金浆料，研究了超声波搅拌处理温度、搅拌时间和超声波输出功率三个重要参数对半固态Al-5％Cu合金组织形貌的影响。结果表明：在熔体处于610℃～680℃之间导入超声波，随着处理温度的升高，合金初生晶粒逐渐趋于细小的球状颗粒；在熔体处于660℃的时候导入超声波，增大超声波输出功率，延长超声波搅拌时间，Al-5％Cu合金初生相形貌由粗大的枝晶状逐渐转变为细小的球状晶粒。其次，为了进一步改善半固态Al-5％Cu合金的组织和性能，先用Al-B和Al-Ti-B变质剂对Al-5％Cu合金进行变质处理，再对其进行超声波搅拌处理，研究超声波处理对变质Al-5％Cu合金组织形貌和细化效果的影响。结果表明，超声波搅拌能够破碎变质Al-5％Cu合金的枝晶，形成颗粒状初生晶粒。最后，用渗流法制备了高体积分数的SiC_p／ZL101复合材料预制块，然后在半固态下通过对复合材料施加高能超声波搅拌，研究了SiC增强颗粒分布的均匀性及基体合金组织形态的控制方法。实验结果表明，用这种方法可以显著克服增强颗粒与基体合金润湿困难以及增强颗粒难以均匀分布的问题，制备了SiC增强颗粒体积分数可以在较大范围内调整的基体合金组织细小，增强颗粒弥散均匀的SiC_p／ZL101复合材料。更多还原

【Abstract】 Semi-solid Al-5%Cu alloy and SiC_p/ZL101 composites have been prepared with high-intensity ultrasonic treatment. In this paper, evolution of semi-solid Al-5%Cu alloy structures changing with the parameters of ultrasonic has been researched, as well as this method used to prepare composites.Firstly, effects of ultrasonic treatment starting temperature, duration and power of ultrasonic treatment on semi-solid Al-5%Cu alloy have been researched. The results indicate that finer primary phase can be obtained with higher treatment starting temperature between 610°C and 680°C , longer and more powerful ultrasonic treatment.Secondly, in order to obtain finer primary phase, modified Al-5%Cu alloy has been stirred by ultrasonic. The fir-tree crystals of modified Al-5%Cu alloy can be broken by ultrasonic stirring.Thirdly, the precast block of SiC_p/ZL101 composites have been prepared by using infiltration method. High-intensity ultrasonic has been used to stir semi-solid composites, in order to research how to homogenize SiC and control the structures of matrix alloy. The results show that wetting property between reinforcement and molten matrix can be improved by using this method. The composites which have homogeneous distribution of reinforced particles and good fine texture of matrix alloy can be prepared.更多还原