摘要
使用水浸式相控阵超声波检测技术对7075铝合金预拉伸厚板进行超声波检测。对不合格品进行解剖后,采用光学显微镜、扫描电子显微镜、能谱仪对缺陷进行了分析。在熔体凝固过程中,高熔点合金元素局部富集,优先凝固形核长大,形成粗大化合物。在轧制过程中粗大化合物被破碎和延长,形成超声波检测时发现的缺陷。通过控制返回料的比例,适当提高铸造温度,防止形成Al-Cr-Ti等粗大化合物;适当延长熔炼时间,使中间合金中的粗大化合物熔解。
Water immersion phased array ultrasonic testing technology was used to inspect 7075 pre-stretching plate. After dissecting the unqualified products, the defects were analyzed by optical microscopy, scanning electron microscopy and energy dispersive spectroscopy. During the solidification process, alloy elements with high melting point aggregate locally, freeze firstly and grow up to form coarse intermetallic compounds. The coarse intermetallic compounds are crushed and extended to form the defects that can be inspected by ultrasonic testing. The formation of Al-Cr-Ti and other coarse compounds can be prevented by controlling the proportion of return material and increasing casting temperature. The coarse compounds in the intermediate alloy can be dissolved by prolonging the melting time.
出处
《热加工工艺》
CSCD
北大核心
2017年第5期248-250,共3页
Hot Working Technology
基金
广西自治区科学研究与技术开发计划(桂科合15104001-4)
广西自治区科学研究与技术开发计划(桂科合15104001-2)
国家国际科技合作专项项目(2014DFA50210)
