带有半导体电热膜的远红外陶瓷热胀系数测定

本文采用一种新的数字图像相关方法测量带有半导体电热膜的远红外陶瓷热胀系数.该方法将有限元的位移模式引入,更适合于微细观领域的高精度测量,可以得到热胀系数随温度变化的曲线.结果表明,陶瓷基体和电热膜均表现出各向异性的热膨胀.在基体和膜热胀系数数值较接近的方向,降温时膜收缩而基体继续膨胀;在基体和膜的热胀系数变化规律一致的方向上,数值上膜的热胀系数要比基体的热胀系数大得多.若已知陶瓷基体和电热膜的应力应变本构关系,就可以根据测试结果计算陶瓷基体与电热膜之间的热应力及残余应力.

Measurement of thermal expansion coefficient of far-infrared ceramic coated semiconductor membrane

A new digital image correlation method (DICM) measurement is utilized to investigate the thermal expansion coefficient of the far-infrared ceramic coated the semiconductor galvanothermy membrane.Compared with those conventional DICM measurements,the new method is fitter for measuring in microscopic field through importing the displacement pattern of finite elements method.The thermal expansion coefficient curve with temperature can be obtained by DICM.The results indicate that both the ceramic substrate and the galvanothermy membrane have anisotropy on thermal expansion.In the direction that the thermal expansion coefficients of the substrate and the membrane are near,the membrane shrinks but the ceramic substrate keeps on swelling,when the temperature lowers.In the direction that the change laws are similar to the thermal expansion coefficients of the substrate and the membrane,the thermal expansion coefficients of the membrane are much larger than those of the substrate.If the relations between stress and strain are known to be the ceramic substrate and the galvanothermy membrane,the thermal stress and the residual stress between the substrate and the membrane can be calculated in terms of the test results.