可伐合金材料放气与微小容器的真空保持

为了研究材料放气对微小容器(容积为10-5m3)真空保持的影响,组建了一套静态升压法测试系统.以经过表面钝化处理的可伐合金为研究对象,测试得到了在特定条件下的放气规律:可伐合金材料经过150℃低温烘烤2h后单位面积表面的放气速率为5.1×10-13～2.1×10-13Pa.m3.s-1.cm-2(1～10h之间),前40h的放气总量约为2.6×10-8Pa.m3.cm-2;四极质谱仪分析显示,放气成分主要是H2,H2O,N2或CO.建立数学模型描述了材料表面放气对容器内部真空度的影响,进而推算出容器内部真空度的变化规律.找出影响微小容器正常工作性能与寿命的关键因素,并提出了改进措施.

Outgassing Rate of Kovar Alloy and Holding Vacuum Degree in Minisized Container

To investigate the effect of outgassing from a certain material on holding vacuum degree in a minisized container (10^-5 m³), a special testing system was developed with the pressure rise method used. The Kovar alloy with passivated surface was taken as sample and its outgassing rate under given conditions was tested. The results showed that the surface outgassing rate per unit area is in the range from 5.1 × 10^-13 to 2.1 × 10^-13 Pa·m³·s^-1·cm^-2 in first 10 hr after baking at 150°C for 2 hr, and the total outgassing throughput per unit surface area is about 2.6 × 10^-8 Pa·m³·cm^-2 for 40 hr. The outgassing composition consists of H₂, H₂O, N₂ and/or CO, as shown in the spectra by quadrupole mass spectrometry. A mathematic model was developed to describe how the process of surface outgassing affects the vacuum degree in a minisized container with the pressure boost formula calculated. The key influencing factors on the normal performance and service life of the minisized container were investigated to find them so as to improve the method proposed.