超声波功率对工业纯镁凝固组织及除气的影响  

Effect of Ultrasonic Power on Solidification Structure and Porosity in Commercial Pure Magnesium

作　　者：何丽娜 李军文 

机构地区：[1]江南大学机械工程学院

出　　处：《特种铸造及有色合金》2013年第2期182-185,共4页Special Casting & Nonferrous Alloys

基　　金：教育部留学回国人员科研启动基金资助项目(20071067);辽宁省自然科学基金资助项目(20082177);辽宁省教育厅创新团队项目(20081224);江南大学科研启动基金资助项目(20100385)

摘　　要：应用金相显微镜观察了不同超声波功率下工业纯镁试样的表面气孔含量,研究了超声波功率对工业纯镁凝固组织的影响。结果表明,未施加超声波时,试样的枝晶宽大,枝晶平均长度和宽度分别是19.23mm和5.96mm;在不同超声波功率条件下,随着超声波功率升高,铸锭中粗大的柱状晶枝晶长度和宽度先减小后增大,功率为250、500、750、1000W对应枝晶长度分别是19.23、14.42、12.07和14.61mm;宽度分别是5.58、3.08、2.21和4.99mm。此外,当超声波功率为0、250、500、750和1000W时,所得试样的气孔率分别是11.2%、3.4%、1.9%、1.48%和2.24%。可以看出,铸锭内气孔率随着超声波功率的增大呈先迅速降低、后缓慢增高的趋势。Effects of different ultrasonic powers on solidification structure of commercial pure magnesium were investigated, and changes of porosity in surface of commercial pure magnesium were observed by OM （optical microscope）. The results show that the coarse columnar dendrites can be observed in the sample without ultra- sonic treatment, where the average length and width reach 19.23 mm and 5.96 mm, respectively. With the in- crease of ultrasonic power, the coarse columnar crystals in the ingot are refined firstly and then coarsened. The average length of dendritic crystals is changed from 19.23 mm to 14.42mm to 12.07 mm and to 14.61 mm; and the average width is changed from 5.58 mm to 3.08 mm to 2.21 mm and to 4.99 mm, corresponding to ultra- sonic power of 250,500,750 and to 1 000 W. In addition, the porosity of the products obtained is changed to 11.2% ,3.4% ,1.9% ,1.48%and to 2.24%, corresponding to ultrasonic power of 0, 250, 500, 750 and 1 000 W. The results show that with the increase of ultrasonic power, the porosities in the ingot is decreased rapidly at first and then increased slowly.

关 键 词：超声波功率 工业纯镁 柱状晶 气孔率 

分 类 号：TG146.22[一般工业技术—材料科学与工程]