5083铝合金铸造板缺陷分析及预防措施

Countermeasures and Defect Analysis of 5083 Aluminum Alloy Casting Plate

针对5083铝合金铸造板进行阳极氧化后,在铸锭横截面产生的色差问题,采用氧化试验比较不同铸造温度和铸造速度对氧化色差的影响,采用水浸式超声波C扫描检测设备对方铸锭进行检测。在不同位置取样,采用光学显微镜、扫描电镜、能谱仪对缺陷进行分析。结果发现,色差区域在方铸锭的1/3~1/4厚度层之间,产生色差与正常区域相比存在较大程度的成分偏析、较粗大的金属化合物、较高的固体氢含量。经试验发现,适当提高浇注温度、减小铸造速度和降低熔体中氢含量,可有效改善铸造板在后续阳极氧化过程中形成的色差问题,提高铸件成品率。

Aiming at anodic oxidation of 5083 aluminum alloy casting plate to form the color difference of the ingot cross section,the influence of different casting temperatures and casting speeds on the oxidation color difference was compared by oxidation test,and the water-immersed ultrasonic C-scan testing equipment was applied to detect the flat ingot.Sampling at different locations,the defects were analyzed by optical microscope,scanning electron microscope and energy dispersing spectrometer.The results indicate that the color difference occurs in the range of 1/3 to 1/4 thickness layer of flat ingot,and there exists a larger degree of component segregation,massive metal compound and higher solid hydrogen content compared with the normal area.In addition,the color difference formed in the subsequent anodic oxidation process of the casting plate can be effectively reduced by increasing the casting temperature,reducing the casting speed and decreasing the hydrogen content of the solution appropriately,enhancing the yield rate.