材料组成特性的统计表征——原位统计分布分析

A NEW METHOD OF STATISTIC CHARACTERIZATION OF SPECIFIC PROPERTIES OF MATERIALS——ORIGINAL POSITION STATISTIC DISTRIBUTION ANALYSIS

提出了原位统计分布分析的新概念,它以测试信息原位性、原始性、统计性为特征,旨在反映材料中较大尺度(cm2)范围内不同组成的定量统计分布规律,系现有宏观平均含量分析及微观结构分析之外的另一种材料性能表征的技术。以火花光谱无预燃单次放电(SDA)、连续激发及高速采集解析技术为基础,研制了金属材料原位分析仪。火花光谱单次放电(SDA)研究指出,在无预燃的情况下,每一个火花单次放电的信号都与该材料对应位置及原始状态相关。当对材料在较大尺度范围内,实现无预燃激发时,则可以获得几万个、几十万、乃至几百万个单次放电的信号,它们分别与各自放电的原始位置及原始状态相对应。在信号统计解析的基础上,提出了一些表征材料性状的新信息,如在材料中,各元素不同位置含量的统计定量分布;各元素偏析度的准确定量计算;元素不同含量在材料中所占的原位(置)权重比率(统计偏析度);统计致密度;夹杂物及粒度的统计定量分布等。该技术成功地应用于连铸等冶金工艺、材料研究及生产的质量判据。

A new concept of original position stutistic distribution analysis （OPSDA） was proposed in this paper. In the OPSDA, testing informations of the specialities of original positions, of initiations and of statistics were taken as the basic characteristics to reflect the quantitative regular distribution patterns of different compositions and their states of aggregation in a relatively large dimension （cm^2） of the materials. OPSDA is a new technique, in addition to the commonly used macrocompositional analysis and microstruetural analysis, to be used for a more accurate and complete description and differentiation of properties of materials. Based on the combining use of the techniques of single discharge analysis （SDA）, continuous scanning excitation spark spectrometry without pre-ignition, and high-speed signal collection and analysis, a totally new instrument of Quantitative Original Position Analyzer for metallic materials was designed and fabricated. As shown by the results of this study, under the condition of excitation without pre-ignition, signals obtained by each spark spectrometric single discharge were closely related to the initial states of the compositions in the respective position of the matetial. When the excitation without pre-ignition was performed in a relatively large area on the material, thousands or even millions of signals of single discharge were obtained , corresponding to the initial states of the compositions in the respective discharged position in the very area of the material. Based on the statistic analysis of the signals, some new informations characterizing properties of the material were obtained, i. e. , the statistic quantitative distribution of contents of various elements at different positions of the material; accurate calculation for the segregation of various elements of the material, the orignal position weight ratio （or the statistic segregation） attributed to different contents of elements in the material, the statistic compactness of the material the quantitative statistic distribution of inclusion and grainity of the material and etc. The technique of OPSDA has been satisfactorily applied to metallurgical technologies and to material researches as a guide of quality judgement of materials.