| LI Xin-kai,WANG Rong,HU Lu-yao,REN Xu-long,WANG Xi-she.The Influence of the Peak Energy of Scanning Electron Beam on the Surface Temperature Field[J],51(7):306-313 |
| The Influence of the Peak Energy of Scanning Electron Beam on the Surface Temperature Field |
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| DOI：10.16490/j.cnki.issn.1001-3660.2022.07.030 |
| KeyWord:scanning electron beams energy temperature field heat source surface modification |
| Author | Institution |
| LI Xin-kai |
Guilin University of Electronic Technology, Guangxi Guilin , China |
| WANG Rong |
Guilin University of Electronic Technology, Guangxi Guilin , China |
| HU Lu-yao |
Guilin Tourism University, Guangxi Guilin , China |
| REN Xu-long |
Guilin University of Electronic Technology, Guangxi Guilin , China |
| WANG Xi-she |
Guilin University of Electronic Technology, Guangxi Guilin , China |
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| Abstract: |
| The mathematical model of energy distribution in the circular downward beam mode of scanning electron beams is clearly defined. Obtain the influence law of energy crest factor on the surface temperature field of 45 steel. Based on the Gaussian heat source model, the energy peak position parameter is introduced to calculate the mathematical model of the energy distribution in the scanning electron beam downward beam mode. The COMSOL software was used to simulate the thermal cycle curve and temperature field of the scanning zone. Revised the electron beam heat source model in the ring-shaped downward beam mode. The results show that the electron beam energy distribution was symmetrically distributed along the center line. The surface energy distribution was related to the deflection angle and the energy peak parameter. When the energy peak parameter was within 0 to 1, the value becomes higher and higher, the larger the first and second energy peaks at point c, the larger the difference between the two. When the parameter was 0, the maximum temperature difference at the sampling point was 1 065 K. The smaller the temperature difference between the longitudinal points of the scanning belt, the smaller the distance between the thermal cycle curves. At the same time, it can be seen from the heat source model that the energy peak has a greater impact on the beam diameter of the ring electron beam, and the maximum ring diameter can be up to 8 mm under the selected basic parameters. When the parameter was 1, the temperature curves of the sampling points are the closest, which indicates that the surface heat distribution under this parameter was uniform. It can be seen from the temperature field simulation diagram that the beam spot temperature varies greatly during the down and converging phases of the electron beam, while the temperature in the middle of the scan was relatively stable, and the temperature difference was basically stable within 20 K. The larger the energy peak parameter, the larger the radius of the high temperature area on the surface of 45 steel, and the maximum temperature will increase accordingly. After 45 steel was subjected to different energy peak coefficients, the width of the scanning zone and the sub-high temperature zone were different. Finally, based on the simulation parameters, the scanning electron beam micro-melting polishing experiment was carried out. It was found that the surface roughness of 45 steel was reduced under this scanning mode, and the surface showed a bright white scanning area relative to the substrate. The scanning area width increased with the increase of the energy peak parameter. This was in full agreement with the simulation results. The surface roughness after scanning electron beam treatment was as low as 0.36 μm relative to the substrate. In the end, the following conclusion can be drawn that the energy peak parameter has a great influence on the energy distribution of the ring electron beam. When ξ = 1, the energy gradient of each position on the surface of the scanning area was the smallest, which was beneficial to the uniform energy distribution under the surface modification of the large area electron beam. |
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