巩春志,王雪松,许建平,等.TiN涂层轴承钢电子束辐照过程电子行为及温度特性研究[J].精密成形工程,2018,10(1):109-115.
GONG Chun-zhi,WANG Xue-song,XU Jian-ping,et al.Behavior of Electrons and Temperature Field of Bearing Steel with TiN Films Irradiated by Electron Beam[J].Journal of Netshape Forming Engineering,2018,10(1):109-115. |
| TiN涂层轴承钢电子束辐照过程电子行为及温度特性研究 |
| Behavior of Electrons and Temperature Field of Bearing Steel with TiN Films Irradiated by Electron Beam |
| 投稿时间：2017-11-16 修订日期：2018-01-10 |
| DOI：10.3969/j.issn.1674-6457.2018.01.013 |
| 中文关键词: 强流脉冲电子束 温度场 薄膜 数值模拟 9Cr18 |
| 英文关键词: HCPEB temperature field thin films numerical simulation 9Cr18 |
| 基金项目:国家自然科学基金（E050803, U1330110） |
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| 中文摘要: |
| 目的 研究辐照过程中电子行为及温度场的分布规律。方法 采用束斑直径为60 mm，平均能流密度为12 J/cm2，脉冲时间为3 μs的电子束，对表面有2 μm厚TiN涂层的9Cr18轴承钢进行强流脉冲电子束辐照模拟，通过建立Monte-Carlo仿真模型，揭示入射电子的平均分布特性及其辐照过程中不同时刻温度场形态。结果 通过仿真电子辐照行为，发现在入射电子能量大于25 keV时电子能够穿透TiN层，进入轴承钢基体中。由于两层物质密度差异，导致在二者交界处轴承钢一侧存在电子能量沉积曲线尖峰，入射电子能量大于35 keV时峰值已经超过涂层内部能量沉积系数最大值，形成特殊的能量沉积形式。结合对辐照温度场的模拟仿真，结果显示，由于交界线处钢一侧能量沉积量大，加热效率高。内部加热速度比表面更快，减小了二者间的温度梯度。同时由于两层物质存在熔点差异，在控制能量的情况下，可以达到两层交界处轴承钢发生少量熔化，TiN涂层不发生熔化的现象。结论 通过控制电子束能量，控制温度场分布形态，实现基体侧熔化，而涂层不发生熔化的特殊改性现象，这为提高涂层膜基结合力提供了新思路。 |
| 英文摘要: |
| To research distribution rules on behaviors of electrons and the temperature field in irradiation, bearing steel 9Cr18 with 2 μm thick TiN films on the surface irradiated by high current pulsed electron beam (HCPEB) were investigated by numerical simulation in the condition of beam diameter of 60 mm, average energy flow density of 12 J/cm2, and electron beam pulse time of 3 μs. The average distribution features of incident electron and the temperature field form in different time of radiation were revealed by establishing a Monte-Carlo simulation model. The simulation results have demonstrated that the electrons could penetrate the TiN layer and reach the bearing steel substrate with a large acceleration voltage (>25 keV). There was a peak for electron energy deposition curve at bearing steel side near the TiN-9Cr18 interface due to the difference of material density. When the incident electron energy >35 keV, the peak value exceeded the max. energy deposition coefficient in the coating and formed a special energy deposition form. In combination with analog simulation, the result showed large energy deposition and high heating efficiency at the steel side of the boundary. The temperature rose more quickly in the interior zone than that on the surface. This decreased the temperature gradient between them. Meanwhile, if the deposition energy was suitable, a small amount of melting happened at bearing steel side while TiN film did not display any melting because of the difference of material melting point. Control of electron beam energy and temperature field distribution form achieves special modified phenomenon in which the coating will not be melt when the substrate side is melt. This may lead to a new way to improve the adhesion between deposited films and substrates. |
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