Physical foundations for surface treatment of materials with low energy, high current electron beams
Physical foundations for surface treatment of materials with low energy, high current electron beams
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DOI：
10.1016/s0257-8972(99)00604-0
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发表时间：
2000-03-01
影响因子：
5.4
通讯作者：
Markov, AB
中科院分区：
文献类型：
--
作者：
Proskurovsky, DI;Rotshtein, VP;Markov, AB
本文综述了利用微秒持续时间的低能量（40 keV）、大电流（40 J/cm(2)）电子束对金属材料进行表面改性的初步研究。在材料研究和温度场、应力场模拟的基础上，研究了脉冲加热下纯金属（Fe）缺陷结构和应变-应力状态变化的规律和机理。本文研究了薄膜-衬底（Fe-Ta， Al-Si和Al-C）体系在脉冲熔炼过程中形成非平衡结构-相态和梯度结构的特点。对于广泛的结构和工具材料（钢、铝和钛合金、硬质合金），已经表明，结构相状态的最显著变化发生在从液态淬火的近表面层，在那里结晶锋的速度达到最大。在该层中，第二相部分或完全溶解，形成过饱和固溶体和纳米级第二相偏析。这大大提高了表面层的电化学和强度性能。结果表明，在动应力作用下，强度增强的改性层明显厚于热影响区。(C) 2000 Elsevier Science S.A.版权所有
The paper presents a review of original investigations on the surface modification of metallic materials with low energy (up to 40 keV), high current (up to 40 J/cm(2)) electron beams of microsecond duration. Based on materials research and on simulations of temperature and stress fields, the regularities and mechanisms for the changes in the defect structure and in the strain-stress state of pure metals (Fe) on pulsed heating are considered. The peculiarities of the formation of non-equilibrium structure-phase states and graded structures on pulsed melting of film-substrate (Fe-Ta, Al-Si, and Al-C) systems have been studied. For a broad spectrum of structural and tool materials (steels, aluminum and titanium alloys, hard alloys) it has been shown that the most pronounced changes in the structure-phase state occur in the near-surface layer quenched from the liquid state, where the velocity of the crystallization front reaches its maximum. In this layer, the second phases are partially or completely dissolved, and oversaturated solid solutions and nanosized second-phase segregates are formed. This substantially improves the electrochemical and strength properties of the surface layer. It has been established that the action of dynamic stresses has the result that the modified layer with enhanced strength properties is substantially thicker than the heat-affected zone. (C) 2000 Elsevier Science S.A. All rights reserved.