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纳秒脉冲弥散放电能够在大气压下产生高功率密度、高电子能量的低温等离子体。为了研究弥散放电等离子体在金属材料表面改性的作用,利用上升沿约150 ns、脉宽约300 ns的MPC-50D纳秒脉冲电源在大气压下(空气)管-板电极之间产生弥散放电,寻找最佳弥散放电参数,并对金属Cu表面进行了弥散处理。研究结果表明:随着重复频率的增加,弥散放电增强,瞬时功率增大,沉积能量增多。当施加电压为31 kV,重复频率为800 Hz,间隙距离为3 cm时,得到最佳的弥散放电效果。此外,采用发射光谱检测到空气中弥散放电中N2(C→B,0-0)的第二正带系和N2+(B→X,0-0)的第一负带系。采用大气压弥散放电等离子体对金属Cu表面处理的结果显示处理后的Cu表面出现孔径约0.5μm的熔孔;Cu的亲水性及表面能有明显提高,在处理90 s后趋于饱和。显微硬度测量结果表明,表层硬度在等离子体处理时间480 s后提高约26.5%。
Nanosecond pulse dispersive discharge can produce high-power density, high electron energy low-temperature plasma at atmospheric pressure. In order to study the effect of diffused discharge plasma on the surface of metal materials, a diffuse discharge was generated between atmospheric pressure (air) tube-plate electrodes using MPC-50D nanosecond pulse power supply with a rising edge of about 150 ns and a pulse width of about 300 ns , To find the best diffusion discharge parameters, and the metal Cu surface dispersion treatment. The results show that as the repetition frequency increases, the dispersion discharge increases, the instantaneous power increases and the deposition energy increases. When the applied voltage is 31 kV, the repetition frequency is 800 Hz and the gap distance is 3 cm, the best dispersion and discharge effect is obtained. In addition, the second negative band system of N2 (C → B, 0-0) and the first negative band system of N2 + (B → X, 0-0) were detected by emission spectroscopy in air. The results of surface treatment of metal Cu by atmospheric pressure Dispersion Discharge plasma showed that there was a molten hole with a diameter of about 0.5μm on the treated Cu surface. The hydrophilicity and surface energy of Cu increased obviously and saturate after 90 s. The results of microhardness measurement show that the surface hardness increases about 26.5% after 480 s of plasma treatment time.