铬锆铜材料的热出气性能研究

采用双通道气路转换法测量了铬锆铜材料的出气率。对经过150℃、保温24 h烘烤的铬锆铜,测得的出气率为2.89×10^-10Pa·L·s^-1·cm^-2(等效氮气),烘烤温度提升至250℃时,铬锆铜的出气率降低约一个数量级。铬锆铜在真空炉中进行400℃、保温24 h除气处理后,仅经过150℃、保温24 h烘烤,出气率即低至1.64×10^-11Pa·L·s^-1·cm^-2,进一步提升烘烤温度,出气率变化不大。通过X射线光电子谱分析铬锆铜在不同温度下的表面成分。在250℃时,铬锆铜表面Cu的氧化物已经基本完全分解,在400℃时,铬锆铜体内的Cr析出至表面,降至室温,Cr仍保留在表面。铬锆铜表面氧化层成分的变化是造成其出气率差异的原因。

Outgassing Performance Research on CuCrZr

The outgassing rate of CuCrZr was measured by switching between two pumping path method(SPP).For CuCrZr baked at 150℃for 24 hours,the measured outgassing rate is 2.89×10^-10Pa·L·s^-1·cm^-2(nitrogen equivalency).When the baking temperature is raised to 250℃,the outgassing rate decreases about an order ofmagnitude.The outgassing rate of CuCrZr,degassed in a vacuum furnace at 400℃ for 24 hours,is as low as 1.64×10^-11Pa·L·s^-1·cm^-2after baking at 150℃for 24 hours.Further increasing the baking temperature,the outgassingrate has little change.X-ray photoelectron spectroscopy was used to analyze the surface composition of CuCrZr atdifferent temperatures.At 250℃,the Cu oxide film on the CuCrZr surface is almost completely decomposed.Whenthe temperature goes up to 400℃,Cr atoms in the CuCrZr alloy are precipitated to the surface.The Cr atoms remain on the surface when the temperature subsequently drops down to room temperature.These results indicate thatthe variation in the oxide film composition of the CuCrZr surface causes the difference in the outgassing rate.