基于仿真的搅拌摩擦焊连接AA2024-T3不同板厚过程对比  

Simulation Based Comparison of Friction Stir Welding of AA2024-T3 Plates with Different Thicknesses

作　　者：张昭[1,2] 陈金涛[1,2] 王晋宝[3] 王辉 刘亚丽[1,2] 张洪武[1,2] 

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,大连116024 [2]大连理工大学工程力学系,大连116024 [3]浙江海洋学院船舶与建筑工程学院,舟山316004 [4]中国海洋石油工程股份有限公司,天津300451

出　　处：《机械工程学报》2011年第18期23-27,共5页Journal of Mechanical Engineering

基　　金：国家自然科学基金(10802017);国家重点基础研究发展计划(973计划;2010CB832704);国家高技术研究发展计划(863计划;2009AA044501);辽宁省教育厅重点实验室科研(LS2010033)资助项目

摘　　要：采用完全热力耦合模型以及修正的库仑模型,分别模拟AA2024-T3铝合金中厚板和薄板的搅拌摩擦焊接过程,通过对比发现搅拌摩擦焊接中材料流动速度的最大值发生在上表面搅拌针前方靠近后退侧,焊接构件上表面材料流动速度明显高于下表面,这说明搅拌头轴肩的旋转对材料流动具有明显影响。相同的焊接参数下,焊接中厚板需要更高的外输入功率以完成搅拌摩擦焊接过程,摩擦能耗在搅拌摩擦焊接中占据主要成分,是温度场形成的主要热源。在焊接薄板时,摩擦能耗占据更高的比例,说明此时的热转换率更高。塑性变形和温度是决定焊接微观结构的主要指标,中厚板搅拌摩擦焊接产生的改善晶粒大小的效果和有效利用外输入能量方面较薄板稍差。因此,无论从能量利用的角度还是对微观结构的推断均发现薄板的搅拌摩擦焊接过程具有更高的效率。Fully coupled thermo-mechanical model and modified Coulomb friction law are used to simulate the friction stir welding of AA 2024-T3 with thin and thick plates respectively.Comparison show that the material flow near the top surface is faster than the one near the bottom surface.The maximum velocity occurs in front of the welding pin in the retreating side on the top surface.This means that the effect of the shoulder on material flow is more obvious near the top surface.Higher power is needed when thick plates are friction stir welded.Friction dissipation is the main energy to consist of the heat source in friction stir welding.Higher proportion can be found in friction stir welding of thin plates to show that heat efficiency is higher.Plastic deformation and temperature are the main factors to affect the microstructures.The improvement of grains and the welding efficiency in friction stir welding of thick plates are weaker.Based on the energy results and the deduction on microstructural evolutions it can be found that higher efficiency occurs in friction stir welding of thick plates.

关 键 词：搅拌摩擦焊接 热力耦合模型 功率 

分 类 号：TG404[金属学及工艺—焊接]