Temperature-stress fields and related phenomena induced by a high current pulsed electron beam
Temperature-stress fields and related phenomena induced by a high current pulsed electron beam
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DOI：
10.1016/j.nimb.2004.06.008
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发表时间：
2004-10-01
影响因子：
1.3
通讯作者：
Guan, QF
中科院分区：
文献类型：
--
作者：
Qin, Y;Zou, JX;Guan, QF
采用物理模型和数值模拟方法研究了强流脉冲电子束（HCPEB）热处理的热力学过程。温度分布的模拟揭示了10（8）-10（9）K/s量级的快速加热/冷却速率，以及在微秒时间和微米深度内的快速熔化和再凝固。它还指出，熔化开始在一个子层约1-2微米的深度，这构成了火山口形成机制。温度引起的动态热应力场可以产生三个主应力，准静态应力，热弹性应力和冲击应力，后两个是应力波。热弹性应力波具有小于0.1MPa的小振幅。而冲击应力波是一种典型的非线性波，其振幅可达几百MPa，比热弹性应力波强得多，对材料组织和性能的影响远远超出热影响区。金属材料表面层的最大准静态压应力可达数百MPa，容易引起表面变形。(C)2004 Elsevier B. V.保留所有权利。
Physical models and numerical simulations are applied to describe the thermal-dynamical processes of the high current pulsed electron beam (HCPEB) treatment. The simulation of the temperature distributions reveals an ultrahigh heating/cooling rate in the order of 10(8)-10(9) K/s, as well as rapid melting and re-solidification within microseconds in time and micrometers in depth. It is also pointed out that the melting starts at a sublayer about 1-2 mum in depth, which constitutes the crater formation mechanism. A temperature-induced dynamic thermal stress fields can then generate three principal stress, the quasi-static stress, the thermoelastic stress and the shock stress, the latter two being stress waves. The thermoelastic stress wave has small amplitudes less than 0.1 MPa. The shock stress wave however is a typical nonlinear wave, several hundreds of MPa in amplitudes, much stronger than the thermoelastic stress wave, and has a strong impact on materials structure and properties far beyond the heat-affected zone. The maximum compressive quasi-static stress in the surface layer reaches several hundreds of MPa, which easily induces surface deformation in metallic materials. (C) 2004 Elsevier B.V. All rights reserved.