摘要
在纯Al强流脉冲电子束表面改性实验的基础上 ,通过数值计算方法对其温度场和熔化过程进行了模拟 ,给出了脉冲半高宽度为 0 5μs、能量为 3J cm2 电子束轰击铝靶后 :熔化深度约为 2 5μm ,与TEM的观察结果一致 ,熔化从 0 4μs开始到 1 6μs结束 ,最先完全熔化的位置约为 1 4μm ,亚表层首先熔化并且迅速膨胀 (沉积的能量在最大射程的 1 3处达到最大值 ) ,体积膨胀力大约为 2 75MPa ,引起了熔体从亚表层通过表层向外喷发 ,熔体的喷发速度约为 1 330m s,随后表面从内向外经历速率为 1 0 9K s的冷却过程 ,因而使得表面形成类似于火山坑状的”熔坑”。
Numerical simulation is used to describe the rapid heating, cooling, melting and solidification processes in aluminum bombarded by high current pulsed electron beam. When pulse duration is 0 5μs and the absorbed energy density is 3J/cm 2, the calculated temperature field indicates that the melted layer depth is about 2 5μm, which is in agreement with TEM observation, and the melting occurs from 0 4μs to 1 6μs. The rate of heating and cooling is up to 10 8~10 9 K/s. The melting and resolidification start at depths of 1 4μm and 2 5μm,respectively. The force of volume expansion is about 275MPa, and the eruptible rate of melting matter is about 1330m/s. Such a sublayer melting is responsible for the formation of craters on the surface, confirming the experimental results.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2003年第1期85-89,共5页
Transactions of Materials and Heat Treatment
关键词
强流脉冲电子束
HCPEB
数值模拟
熔坑
high current pulsed electron beams (HCPEB)
numerical simulation
crater