强脉冲离子注入中的脉冲能量效应研究

Study of intense pulsed energy effects for high power pulsed ion beam implantation

在脉冲离子束流密度为１５－１２０Ａ／ｃｍ２、脉宽为５０－１５０ｎｓ、加速电压为１５０－２６０ｋＶ范围内，在１×１０４ｃｍ－２的低注量水平上，研究了高功率Ｃｎ＋＋Ｈ＋混合离子束注入４５号钢样品的强脉冲能量效应．摩擦磨损和微观硬度测量以及ＳＥＭ和Ｘ射线衍射分析表明，上述低注量强脉冲离子束注入可以改变材料表面的微观结构和力学特性，而且强烈依赖于单个脉冲离子束的功率密度和能量密度，在相同离子注量条件下，普通Ｃ＋＋Ｈ＋离子注入对４５号钢样品表面微硬度和摩擦系数未见明显影响．直接证明了强脉冲能量效应在离子注入中是相对独立于注入元素掺杂效应的又一可利用的重要效应．基于一维导热模型，讨论了强脉冲能量效应以及脉冲离子束功率密度对离子束材料表面改性的作用。

In this paper the intense pulsed energy effects of high power pulsed ion beams (HPIBs) are proved to be very important and useful in ion beam implantation. Three groups of 45# steel samples were implanted with the pulsed ion beams of Cn+ + H+ at the acceleration voltage of 150-260kV for the pulse duration of 50-150ns with the current density of 15-120A/cm2, while a low ion dose of about 1 ×1014cm-2 was kept for all implanted samples. Then their tribological properties as well as microhardness were measured, and their morphology and structure information were given by using SEM and X-ray diffraction analysis. The results showed that the materials' surface properties and microstyucture have been modified due to the HPIB implantation even at such low level of ion dose, and the modifications strongly depended on the pulsed power density and pulsed energy density of HPIBs. These phenomena were considered as the intense pulsed energy effects and discussed on the basis of one dimensional heat conduction model. Meanwhile, the hardly changed surface microhardness and friction coefficient of 45# steel samples implanted with traditional (C++H+) ions at an ion dose of 1 ×1014cm-2 was given for a demonstration, in which the intense pulsed energy effects are relatively independent of the ion doping effects.