AZ91D散热性能的研究

Study on the thermal dispersion of AZ91D

采用稳态测量方法测量镁合金AZ91D、铝合金及紫铜的导热系数,研究了从室温到350℃范围内试件在自然散热条件下的温度变化曲线.利用合金材料散热的物理微观模型从理论上对散热实验进行了分析,利用分子运动理论解释了散热过程.实验和理论研究结果表明:材料容热能力ρc是影响材料散热性能的关键因素,材料的ρc值越小,降温速度越大,散热效果越明显.由于镁合金ρc小于铝合金及紫铜,镁合金自然冷却时降温速度更快,散热更迅速,因而镁合金具有优良的散热性能.

Thermal dispersion curve and thermal conductivity of magnesium alloys, aluminum alloys and red copper samples were measured from room temperature to 350 ℃. The quantitative distinction of thermal dispersion curve of magnesium alloys and other materials were derived from the experiment. It is shows that magnesium alloy＇s temperature dropped faster than other two alloys in common circumstance with uniform shape and size. From the microcosmic model based on molecular motion kinetic theory in physics, the same function can be deduced as experiment result. So it can be concluded that for the good thermal conductors the ratio of specific heat and surface area is the most important factors, which determined the thermal dispersion ability of the materials. And for magnesium alloys, the ratio is smallest than other two materials in common shape and size, and has the best thermal dispersion ability.