3-12. High-throughput characterization of elemental distribution based on micro X-ray fluorescence spectroscopy

LI Dongling^1,2, ZHAO Lei^1,2,SHEN Xuejing^1,2,WANG Haizhou^2,3

1. The NCS Testing Technology Co., Ltd. 2. Beijing Key Laboratory of Metallic Materials Characterization;
3. Central Iron & Steel Research Institute

Abstract: The elemental quantitative distribution characterization method based on micro X-ray fluorescence spectroscopy was applied to the high throughput non-destructive determination of components distribution in graded stainless steels, other alloy gradient materials and directionally solidified single crystal superalloys. Figure 1 shows the distribution of Ni and Cr in the deposition surface of the additive manufactured gradient stainless steel. It can be seen that the content of Ni has obvious gradient change, and the gradient range is closely related to the height of the cladding layer. The spot size and scanning speed of the laser pulse can also affect the elements distribution in the same cladding layer and the concentration fluctuation of some elements is obvious especially in the welding pools overlap area of different laser pulses. Due to the high resolution of micro X-ray fluorescence, the dendrite segregation of elements in single crystal superalloy has also been finely characterized. The quantitative distribution results show that there is obvious dendrite segregation in many elements of single crystal superalloy. The results show that W, Re, Co have obvious positive segregation in dendrite trunk, while Cr, Mo, Ta, Al have obvious negative segregation, which is coincidence with characterization results obtained by electron probe microanalysis technology.

This method can also be used to characterize the composition distribution of other bulk materials, as well as the film thickness distribution. It has the advantages of non-destructive, high efficiency and good quantification. With the structural improvement of light source and the development of detector technology, it is expected to make further progress in the detection of light elements, the improvement of micro area resolution and the reduction of the lower limit of element determination. It can provide technical support for high-throughput characterization of material genetic engineering.

Keywords: Micro X-ray fluorescence spectroscopy; Elemental distribution; Graded stainless steel, Single crystal superalloy; High throughput characterization

Figure 1 Elemental distribution characterization for graded stainless steel

图1 增材制造不锈钢梯度材料中元素的成分分布表征

基于微束X射线荧光光谱的成分分布高通量表征方法研究

李冬玲^1，2，赵雷^1，2，沈学静^2，3，王海舟^2，3

1.钢研纳克检测技术股份有限公司；2.金属材料表征北京市重点实验室；3.钢铁研究总院

摘要：提出了一种大范围内材料成分分布的无损高通量定量表征方法。将基于微束X射线荧光光谱的元素定量分布表征方法应用于大尺寸不锈钢及其他合金梯度材料、定向凝固单晶高温合金材料中成分分布的无损高通量定量分布表征。图1为激光增材制造梯度不锈钢样品沉积面上Ni，Cr元素的二维分布图，可以看到Ni元素含量有明显的梯度变化，其梯度区间与熔覆层高度密切相关，脉冲激光的束斑尺寸和扫描速度也会对同一熔敷层内成分分布造成影响，尤其是在不同激光熔池搭接处成分分布波动明显。由于微束X射线荧光光谱的高分辨率，单晶高温合金中元素的枝晶偏析也实现了精细表征，从成分定量分布结果表明，单晶高温合金中的多个元素存在较为明显的枝晶偏析，其中W, Re, Co在枝晶干有明显的正偏析，而Cr, Mo, Ta, Al在枝晶干存在较为明显的负偏析，这与电子探针的表征结果也有很好的一致性。

该法还可以应用于其他块体材料的成分分布表征，也能应用于薄膜厚度分布表征，具有无损、高效和定量性好的优点，随着光源结构的改进，探测器技术的发展，有望在轻元素的探测，微区分辨率的改进、元素灵敏度的提高等方面取得进一步的进展，为材料基因工程的高通量表征提供技术支撑。

关键词：微束X射线荧光光谱；成分分布；梯度不锈钢；单晶高温合金;高通量表征