不同测试位向下C/C复合材料磁电阻效应

MAGNETORESISTANCE OF C/C COMPOSITE IN DIFFERENT MEASURING ORIENTATION

对几种C/C复合材料在不同的测试位向(指外加磁场与材料某特定表面的夹角)下的磁电阻效应进行了研究。研究结果表明,C/C复合材料不同位向下的磁电阻大小不同,且不同结构、不同处理工艺的材料出现最大磁电阻的位向不同;已石墨化的材料各位向磁电阻均呈正值,未石墨化材料各位向的磁电阻为负值,但它们的绝对值都随测试温度的增高而线性降低;温度升高到一定值,一些材料的磁电阻为0不再变化;外磁场一定时,对同一材料各位向下磁电阻-温度曲线进行回归,所得回归方程斜率项相同,截距项不同;将各位向磁电阻排序发现,不同工艺和结构的材料位向序列不同;外加磁场强度的改变,只改变各位向磁电阻的大小,不影响位向序列。

The magnetoresistance of C/C composite was studied in different measuring orientation. The magnetoresistance varies with the measuring orientation; the maximal magnetoresistance was found in different orientation for the materials that have different structures and different technics. Graphitized materials have positive magnetoresistance, and nongraphitized materials have negative magnetoresistance, but both of its absolute value increase with temperature rising. Magnetoresistancetemperature is a linear function in every measuring orientation. When the temperature is high enough, some materials' magnetoresistance will keep unchanged. By regressing the magnetoresistancetemperature curves, the slopes of the obtained equations are equal but the intercept is unequal. The magnetoresistance of every orientation is ranged, and dissimilar orientation serials are found for different materials. When the intensity of the magnetic field changes, the value of magnetoresistance changes, but the orientation serial does not change.