真空热试验中材料放气的放气量及其导热问题

材料放气是真空热试验中常见的现象,文章分析了材料放气的过程和机理,给出了计算放气量的两种方法。对于平缓的材料出气过程,从气体扩散的角度,利用费克第二定律求解得到了平板材料模型的气体浓度分布,并由此计算出放气量;对于短时间内的剧烈放气过程,是根据放气后的抽气试验数据拟合出抽气曲线,以此反算放气量的大小。文章最后还分析了由于放气而引起的低压气体导热过程,为真空热试验中的相关问题提供了理论分析依据。

Material Outgassing Amount and Thermal Conduction in Vacuum Thermal Test

Material outgassing is a common phenomenon in vacuum thermal test. In this paper, the course and mechanism of material outgassing are analyzed, and two methods of calculating outgassing amount are proposed. For a gradual outgassing course, the gas consistence distribution for a flat board model and the gas amount formula are derived according to the Second Fick Law for gas diffusion. For an acute outgassing course in a short time, a fitting curve is obtained according to the pumping data after outgassing, so the outgassing amount is obtained from the curve. Furthermore, the course of thermal conduction caused by material outgassing is analyzed as a theoretical basis to solve related problems in vacuum thermal test.