用α-Al_2O_3研究比热测试与MDSC条件的相关性

The Dependences of Specific Heat of α-Al_2O_3 on the Testing Conditions of Modulated DSC

通过α-Al2O3的比热测试，研究了调制式差示扫描量热法（MDSC）测量比热（cp）与温度（T）、线性升温速率（β）、温度调制振幅（AT）和调制周期（p）的相关性，并对测试误差进行校正．实验结果表明：Cp随T提高和p延长而增大难；β和AT对Cp影响不大；P=30s时实测值（Cp^ms）与文献值（Cp^rtd）的相对误差（Er^ms）最小，在温度为100-200℃范围小于3％；导出了对Cp^ms进行修正的多项式校正参数，在p为20-50s、温度为100-200℃范围，修正后的比热（Cp^md）与文献值的相对误差（Ep^md）小于1．5％．

The dependences of specific heat （Cp） of α-Al2O3 on the testing conditions of MDSC, such as temperature （T）, linear heating rate （β）, modulated amplitude （AT） and modulated period （p）, were studied. The results showed that the measured specific heat （Cp^ms） increased with the increase of T and p, while was hardly affected by fl and At. The relative error （Er^ms） between Cp^ms and literature value （Cp^td reached a minimum value when an optimum p was kept to be 30 s, which was less than 3% in the temperature range from 100 to 200 ℃. An emendation parameter to modify Cp^ms was obtained. The modified Cp^md shows good agreement with the literature Cp^td, The relative error Er^md between Cp^md and Cp^td was less than 1.5%, when the temperature varied from 100 to 200 ℃ and the p value changed from 20 to 50 s.