微观应变测定原理及应用

Principle and Application of Determination of the Microstrains

中文关键词:  X射线衍射  微观应变  氧化镁纤维

英文关键词:X-ray diffraction  microstrains  MgO fiber

中文摘要:

      介绍了用X射线测定多晶体材料微观应变的新方法(非卷积方法).该方法依据多晶体衍射X射线服从振幅/强度叠加原理,认为微细晶粒和畸变晶粒对衍射线强度的贡献是能够分离的;又根据布拉格方程,导出两者在衍射线角位移上的关系,并进一步推出测定晶粒尺寸及微观应变的表达式,从而实现了多晶不完善材料晶粒尺寸及微观应变的直接测量.通过对MgO纤维微观应变的测定,证实该方法的实用性和可靠性.

英文摘要:

      A new method (non-convolution method) is introduced for determining the microstrains of polycrystalline materials by X-ray diffraction. The method is based on the principle of superposition of X-ray diffraction-line amplitudes/intensities from polycrystallites. It is considered that the contributions of the X-ray diffraction-line intensities from the size-strain crystallites could be separated. On the other hand, based on the Bragg law, it leads to the relationship between the angular deviations of diffraction X-ray lines from the size-strain crystallites. A series of expressions is therefore derived for determination of the size and microstrains of imperfect crystallites, for which the name direct determination method is proposed. The practicability and reliability are evidenced by the determination of as example MgO-fiber microstrains presented.