摘要: |
采用完全热力耦合模型研究了搅拌头形式对搅拌摩擦焊接中材料变形和温度场的影响.结果表明,搅拌头轴肩形状变得平坦会导致焊接温度和塑性变形程度的降低,有效功率会减少.采用锥形搅拌针时焊接温度较柱形搅拌针低,这是由于接触面滑动率减少导致摩擦热减少,但是此时,塑性变形会增加.采用尺寸较小的搅拌头轴肩时,摩擦面积的减小是导致焊接温度降低的主要原因,为了提高焊接温度和焊接质量,必须在使用小轴肩时采用较高的搅拌头旋转频率. |
关键词: 搅拌摩擦焊接 完全热力耦合模型 有限元法 搅拌头形状 |
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基金项目:国家"973"计划资助项目(2010CB7317042,010CB832704);国家自然科学基金资助项目(10802017) |
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Effect of pin shapes on material deformation and temperature field in friction stir welding |
ZHANG Zhao1, LIU Huijie2
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1.State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, Liaoning 116024, China;2.State Key Laboratory of Advanced Welding Production Technology, Harbin Institute of Technology, Harbin 150001, ChinaState Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Dalian University of Technology, Dalian, Liaoning 116024, China
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Abstract: |
Fully coupled thermo-mechanical model was adopted to study the effect of pin shapes on deformations and temperature fields in friction stir welding.Results indicated that a flatter shoulder could lead to the decrease of temperature and plastic deformation.The efficient power decreased simultaneously.With comparison to the case of cylindrical pin,the temperature decreased in the case of conical pin.The decrease of the frictional heat induced by the decrease of the slipping rate was the reason for such a decrease of temperature.The plastic deformation increased when the conical pin was adopted.When the smaller shoulder was used,the temperature decreased obviously,which was caused by the decrease of the frictional area.So,higher angular velocity should be used when the smaller shoulder was used to improve the welding temperature and the weld quality. |
Key words: friction stir welding fully coupled thermo-mechanical model finite element method tool shape |