| 摘要: |
| 为修复飞机TC2钛合金结构裂纹，应用YAG激光器进行了TC2钛合金的焊接实验。利用扫描电镜（SEM）和电子显微硬度仪分析了工艺参数对焊缝形貌和焊缝截面显微硬度的影响。结果表明：随着电流的升高，焊缝的熔宽逐渐增加，焊缝截面形貌由钉型向X型转变；随着焊接速度的增大，焊缝的熔宽呈减小趋势。采用电流150 A、脉宽10 ms、频率4 Hz、焊接速度2.0 mm/s的工艺参数可获得宏观质量良好的焊缝。焊缝熔合区可能为针状马氏体α′交织成的网篮组织；热影响区为75 μm左右的环形带，其组织可能是由等轴的α相和针状马氏体组成，靠近熔合线部分较之远离熔合线的区域针状马氏体数量更多且更加密集，靠近熔合线区域有逐渐减弱的再结晶，再结晶尺寸明显大于基材；焊缝截面的显微硬度呈明显的阶梯状分布，基材的硬度在310~350 HV0.5之间，熔合区的硬度在500~600 HV0.5之间，熔合区硬度相对于基材提高了60% 左右。 |
| 关键词: TC2钛合金 激光焊接 工艺参数 微观组织： 显微硬度 |
| DOI： |
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| 基金项目: |
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| The Welding Technology and the Microstructure of TC2 Alloy By Nd:YAG Laser |
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FU peng–fei, HU Fang–you , CUI Ai–yong , ZHAO Pei–zhong , LU Chang–liang , HU Bin
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Naval Aeronautical Engineering Institue (NAEI), Qingdao Shandong, 266041
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| Abstract: |
| In order to repair the cracked structure of aero TC2 alloy, the welding experiment of TC2 alloy was carried out by YAG:laser. The effect of process parameters on welding seam was investigated. The microstructure of welding seam was observed by SEM. The microhardness of the crosssections of welding seam was measured. The results show that the weld width increases with the increasing of electric current. At the same time, the microstructure of welding seam changes from T to X type. The increase of welding rate reduces the weld width. According to the test data, a good quality of welding seam can be obtained by the electric current of 150 A, pulse width of 10 ms, frequency of 4 Hz and the welding rate of 2.0 mm/s. The fusion zone is attributed to basketweave microstructure consisted of needle type martensite α′. The heat affected zone is a circumferential band with the dimension of 75 μm, which is consisted of needle type martensite and equiaxed α phases. There is more and denser needle type martensite in the region near the fusion line than that away the fusion line. The trend of recrystallization become weak gradually close to the fusion line. The recrystal grain size is obviously greater than that in the base material. Microhardness along the crosssections is distributed like a ladder. The microhardness of the base material is from 310 to 350 HV0.5. And the microhardness of fusion zone is enhanced by 60% to 500~600 HV0.5. |
| Key words: TC2 alloy laser welding process parameters microstructure microhardness |
