X射线荧光光谱法测定变形铝合金中合金元素的影响因素探讨  

Discussion on influencing factor on determination of alloying element in wrought aluminum alloy by X-ray fluorescence spectrometry

作　　者：张祥 陆晓明[1] 张毅[1] ZHANG Xiang;LU Xiaoming;ZHANG Yi(Reasearch Institute of Baoshan Iron and Steel Co.,Ltd.,Shanghai 201900,China)

机构地区：[1]宝山钢铁股份有限公司研究院,上海201900

出　　处：《冶金分析》2023年第5期10-16,共7页Metallurgical Analysis

摘　　要：X射线荧光光谱法(XRF)是一种近样品表面分析方法,采用XRF分析变形铝合金中合金元素时,需考虑样品表面状态以及合金元素在基体中的分布对测定造成的影响,具体表现在砂带研磨次数引起的样品表面状态变化、不同牌号变形铝合金金相组织(析出相)差异以及热处理工艺不同对测定造成的影响。为此,实验以2xxx、5xxx、6xxx、7xxx变形铝合金为研究对象,详细讨论了砂带研磨次数、析出相类型及热处理工艺对合金元素测定的影响,得出了以下结论:(1)样品采用120目氧化锆砂带抛光,但随着砂带研磨次数的增加,样品表面状态会发生变化,受合金元素测量无限厚度和样品表面阴影效应的影响,轻元素Mg和Si受样品表面状态影响较大,测定值随砂带研磨次数逐渐升高并趋于稳定,而中重元素Cr、Fe、Ti、Mn、Cu、Zn测定值基本不受影响,为此砂带在使用前需钝化至稳定状态。(2)对4个牌号共20块变形铝合金标准样品进行测定并绘制校准曲线,发现轻元素Mg和Si校准曲线线性关系不够理想,而中重元素Cr、Fe、Ti、Mn、Cu、Zn的线性关系良好,这可能是因为合金元素形成的析出相类型以及采样体积不同所导致的,建议测量轻元素时,按照变形铝合金的牌号进行分类,以消除析出相类型不同造成的影响。(3)轻元素的测定受析出相尺寸影响较大,而热处理工艺控制着析出相的尺寸大小,退火态下析出相尺寸大于淬火态和淬火时效态。受析出相吸收效应的影响,退火态下,7xxx系铝合金中Mg的测定结果小于淬火态和淬火时效态;Si因含量较低,在此不讨论对其影响;中重元素Zn、Cu、Cr、Fe、Mn、Ti测定值基本不受影响。X-ray fluorescence spectrometry(XRF)is a near-sample surface analysis method.During the analysis of alloying elements in wrought aluminum alloy by XRF,the influences of sample surface state and the distribution of alloying elements in the matrix on determination should be considered.Specifically,the influences on determination include the sample surface state change caused by the grinding times with abrasive belt,the difference of metallographic structure(precipitated phase)in wrought aluminum alloy with different grades,and the difference of heat treatment process.2xxx,5xxx,6xxx and 7xxx wrought aluminum alloys were selected as the object of research.The influences of abrasive belt grinding times,precipitated phase type and heat treatment process on the determination of alloying elements were investigated and discussed.The following conclusions were obtained:(1)The sample was polished with 120-mesh zirconia abrasive belt.However,the surface state of the sample changed with the increase of grinding times.Due to the infinite thickness of alloying elements and the shadow effect of the sample surface,the light elements(Mg and Si)were greatly affected by the sample surface state,and the measured values gradually increased and tended to be stable with the increase of grinding times.But the measured values of medium and heavy elements(Cr,Fe,Ti,Mn,Cu and Zn)were basically not affected.Therefore,the abrasive belt should be passivated to be a stable state before use.(2)Total standard samples of wrought aluminum alloy in 4 grades were determined to prepare the calibration curves.It was found that the linear relationships of light elements(Mg and Si)were not ideal,while the linear relationships of the medium and heavy elements(Cr,Fe,Ti,Mn,Cu and Zn)were good,which were possibly caused by the different types of precipitated phase formed by alloying elements and the sampling volumes.It was suggested to classify the wrought aluminum alloy according to the grade during the measurement of light elements to eliminate the influenc

关 键 词：变形铝合金 X射线荧光光谱法(XRF) 砂带研磨次数 析出相 热处理工艺 

分 类 号：O657.34[理学—分析化学] TF031[理学—化学]