Rietveld辅助晶格常数法表征Ti(C,N)多相成分

Characterization of Phase Structure of Ti(C,N)Raw Materials with Rietveld-Assisted Lattice Constant Method

目前用来控制Ti(C,N)粉末质量的检测手段主要为化学分析方法,偏重于C、N、O等元素的控制。本文建立Rietveld辅助晶格常数法,通过相结构来鉴别Ti(C,N)固溶相粉末的成分差异。结果表明:新方法的模型构建与前提假设是可行的,但对于高角度分峰不明显的谱图,需要从逻辑层面上如拟合参数、工艺条件或物理意义等对拟合结果的合理性进行判定,才能避免多解,确定唯一解;模型构建得到的Ti(C,N)相结构存在多组解的情况下,不影响理论C、N含量的推导计算。

The current methods used in quality control of Ti(C,N)raw materials are mainly chemical analysis methods,which focus on the control of C,N,O,and other elements.This paper establishes the Rietveld-assisted lattice constant method,which identifies the composition differences of Ti(C,N)powders with solid solution phase by their phase structure.The results show that the structural model and presumption of the method are feasible,but if there is no obvious peak splitting at high angles in the spectrum,it is necessary to judge the rationality of fitting results from the logic level for getting the unique solution,such as fitting parameters,technological conditions,physical significance,and so on;the derivation and calculation of the theoretical content of C and N are not affected even when the Ti(C,N)phase structure constructed by the model has multiple solutions.