内径20mm导向套筒内壁处理(2):空心阴极混合气体放电特性研究

Treatment of Inner Surface of Guide Sleeve with Inner Diameter of 20mm(2):Discharge Characteristics of Mixed Gas Hollow Cathode

针对高端阀门内径20mm导向套内壁DLC处理,采用高频高压脉冲电源,分别研究了氩气和混合气气氛下脉冲电压、脉宽、频率以及工作气压等参数对管内空心阴极放电伏安特性的影响规律。结果表明:轴向对齐的五个小管内均实现了空心阴极放电,氩气条件下放电电流表现出明显空心阴极放电特征,而混合气条件下电流幅值较为平整。脉冲电压或气压的提高有利于提高放电电流,而脉冲频率的增加会使得峰值电流略有下降,脉宽的增加使得单纯氩气条件下电流峰值逐渐增加,而对于混合其他条件下的峰值电流影响不大,仅使平均电流增加。固定气压10Pa条件下,乙炔流量的变化对放电电流的影响不大,有利于扩大DLC薄膜沉积的工艺窗口范围。以上研究结果为高端阀门小直径导向套等内壁DLC薄膜制备提供工艺基础。

Aiming at the DLC treatment of inner surface of 20 mm guide sleeve of high-end valve,the effects of pulse voltage,pulse width,frequency and working pressure on the volt-ampere characteristics of hollow cathode discharge in tube under argon and mixed atmosphere were studied by using high frequency and high voltage pulse power supply. The results show that the hollow cathode discharge is realized in the five axially aligned tubes. The discharge current under argon condition shows obvious characteristics of hollow cathode discharge,while the current amplitude under mixed gas condition is relatively flat. The increase of pulse voltage or pressure is beneficial to the increase of discharge current,while the increase of pulse frequency decreases the peak current slightly,and the increase of pulse width increases the peak current gradually under the pure argon condition,but has little effect on the peak current under other mixed conditions,only increases the average current. Under fixed pressure of 10Pa,the change of acetylene flow rate has little effect on discharge current,which is beneficial to enlarge the process window range of DLC film deposition. The above results may provide a technological basis for the preparation of DLC film on inner wall of small diameter guide sleeve of high-end valves.