基于微束X射线荧光的铸轧7B05铝合金元素偏析研究  

Element Segregation of Cast-Rolled 7B05 Aluminum Alloy Based on Microbeam X-Ray Fluorescence

作　　者：韩冰[1] 孙丹丹 万卫浩 王辉 董彩常 赵雷 王海舟 HAN Bing;SUN Dan-dan;WAN Wei-hao;WANG Hui;DONG Cai-chang;ZHAO Lei;WANG Hai-zhou(Central Iron&Steel Research Institute,Beijing 100081,China;Qingdao NCS Testing&Corrosion Protection Technology Co.,Ltd.,Qingdao 266000,China;Beijing Key Laboratory of Metal Materials Characterization,Beijing 100081,China)

机构地区：[1]钢铁研究总院,北京100081 [2]青岛纳克检测防护技术有限公司,山东青岛266000 [3]金属材料表征北京市重点实验室,北京100081

出　　处：《光谱学与光谱分析》2022年第5期1413-1419,共7页Spectroscopy and Spectral Analysis

基　　金：国家重点研发计划项目(2017YFB0702303)资助。

摘　　要：材料内部微观尺度上成分、组织结构控制精度低、波动大是制约高铁铝合金国产化进程的重要原因,因此从微观尺度上研究大尺寸铝合金成分均匀性至关重要。鉴于目前研究铝合金偏析的区域通常较小且不连续,定量统计方法过于简单。使用微区分辨率较高的微束X荧光与原位定量统计分布分析技术相结合的方法,从点、线、面、频度分布等方面对成分分布数据进行解析,研究了较大尺寸范围内铝合金成分偏析的规律。研究结果表明铸轧7B05铝合金截面中心层存在接近2 mm的偏析带,Al,Cr,Ti和Zr元素为正偏析元素,中心层含量比上下表面高,Cu,Fe和Zn元素为负偏析元素,中心层含量比上下层含量低;各元素含量分布的统计偏析程度整体较小,分布最均匀的为Al元素,统计偏析度最小为0.01%,Ti和Fe元素分布较不均匀,统计偏析度分别为0.81%和0.6%;Fe元素与Mn元素在面分布中出现较明显的点状偏析,这是由于铝合金铸造过程中经显微偏析形成的金属间化合物,在后续的热轧成型中破裂成多个连续排列的第二相所致。使用激光诱导击穿光谱法对该方法所得数据进行验证,结果显示在30 mm×6 mm尺寸范围内所测元素面分布与线分布结果与荧光结果趋势完全一致。综上所述,使用微束X荧光结合原位统计的方法,对铸轧7B 05铝合金点、线、面、频度分布及偏析程度的计算,可提供大量分析数据,对于量化研究大尺寸范围内轧板截面组织、性能的波动趋势具有重要意义。The low control accuracy and large fluctuation of the composition and microstructure in the micro-scale of the material are the fundamental reasons restricting the localization process of high-speed train aluminum alloy.Therefore,studying the composition uniformity of large size aluminum alloy from the micro scale is very important.Because the research area of microsegregation in aluminum alloy is usually small,the research method of macrosegregation is too simple.In this paper,the distribution results of alloy elements in the 7 B05 aluminum alloy sheet were obtained by micro-beam X-ray fluorescence,and the composition distribution data were analyzed from the point,line,surface,frequency distribution.The results show a segregation band of about 2 mm in the central layer of the cast and rolled 7 B05 aluminum alloy section.Al,Cr,Ti and Zr are positive segregation elements,and the content of the central layer is higher than that of the upper and lower layers.Cu,Fe and Zn are negative segregation elements,and the content of the central layer is lower than that of the upper and lower layers.The results show that the degree of statistical segregation of each element is small as a whole,the most uniform distribution is the Al element,and the minimum degree of statistical segregation is 0.01.The distribution of Ti and Fe elements is not uniform,and the degree of statistical segregation is 0.81 and 0.6 respectively.The obvious point segregation of Fe and Mn in the plane distribution is since the intermetallic compounds formed by microscopic segregation during the casting process break into several continuous arranged second phases during the subsequent hot rolling forming.Laser-induced breakdown spectroscopy(LIBS)is used to verify the data obtained by this method.The results show that the surface distribution and line distribution of elements measured in the size range of 168 mm;are consistent with the fluorescence results,proving this method’s repeatability and reliability.In conclusion,the calculation of point,line,pl

关 键 词：X射线荧光 原位统计分析 铸轧铝合金 显微偏析 正偏析 负偏析 

分 类 号：O657.3[理学—分析化学]