微纳晶体材料体膨胀系数测定和计算方法

为解决微纳尺度晶体材料膨胀系数无法直接测量的现状,文章提出一种适用的测试思路及计算方法.该方法基于材料在不同温度下的XRD衍射图谱获得晶胞晶格常数,通过"晶格常数-温度"拟合,计算各个物相晶轴的线膨胀系数,进一步计算获得材料的体膨胀系数.采用该方法对单相高锡焊料及多相PbSn合金焊球进行测试,获取其体膨胀系数,证实方法...

Measurement and calculation of the volume coefficient of expansion for micro/nano crystalline materials

Herein, a method for measuring the volume coefficient of expansion of micro/nano-scale crystalline materials is proposed in order to solve the problem that the parameter is difficult to obtain directly. The volume coefficient of expansion of materials is calculated by using the linear expansion coefficient of crystal axes of each phase, which is available through linear fitting of lattice constant with temperature based on the calculated lattice constants from the XRD diffraction patterns at different temperatures. The examples of single-phase tin solder and multi-phase PbSn solder balls have proved the feasibility and effectiveness of the proposed method.This method can be used to measure the volume coefficient of expansion of micro/nano-scale samples,including the micro-sized structures, film materials, lead wires, solders and other materials for electronic components. This method is simple and efficient in operation without any specimen requirements. Therefore,the study provides a new way to measure the thermal expansion coefficient of micro/nano-scale materials,which has tremendous applicable value.