预热铝合金搭接激光焊.pdf

第45卷第2期
机械工程学报
Vol45 No.2
2009年2月
JOURNAL OF MECHANICAL ENGINEERING
Feb
2009
DOI:103901/ME.2009.02.251
预热铝合金搭接激光焊
李永强1赵贺2张伟华1赵熹华1
(1.吉林大学材料科学与工程学院长春130022
2.哈尔滨工业大学现代焊接生产技术国家重点实验室哈尔滨15000
摘要:为了研究预热对铝合金搭接激光焊的影响,使用Nd:YAG激光器和1.4mm厚的5A03H24铝合金板材,分别在无预热
和预热300℃条件下进行了搭接激光焊试验。结果表明,预热可在熔深、熔宽、热影响区宽度和拉剪力基本不变的同时大幅
度提高焊接速度。预热高速焊接与无预热激光焊相比,焊缝中Mg元素质量分数无显著区别;拉伸断口显徵组织都属于孔
聚集型塑性断裂;焊缝组织都由柱状枝晶和等轴树枝晶组成,并且熔合线附近的柱状枝晶组织相近;焊缝和母材硬度比无预
热时有所下降,其中焊缝下降幅度大于母材
关键词:激光焊接预热搭焊铝合金焊接参数
中图分类号:TG457.1
Laser Lap Welding of Aluminum Alloy with Preheating
LI Yongqiang ZHAO He" ZHANG Weihua ZHAO Xihua
(1. College of Materials Science and Engineering, Jilin University, Changchun 130022;
2. State Key Laboratory of Advanced Welding Production Technology,
Harbin Institute of Technology, Harbin 150001)
Abstract In order to investigate the effect of preheating on the laser lap welding, Nd: YAG laser and aluminum alloy 5A03H24 plate
of 1. 4 mm thick are used to carry out experiments of laser lap welding without preheating and with preheating a 300 C respectively
The results indicate that preheating can accelerate welding speed greatly while the penetration depth and width, heat affected zone
width and tensile shear strength are basically unchanged. Compared with laser welding without preheating, M element concentration
weld is almost the same during high speed welding with preheating. The tensile fracture microstructures are all micro-void
coalescence type plastic fractures. The weld structures are all composed of columnar dendrites and equiaxial dendrites, and the
columnar dendrites near fusion line are similar in structure. However, the hardness of weld and base metal is decreased, and the
former decreases more in hardness than the latter
Key words: Laser welding Preheating Lap welding Aluminum alloy Welding parameters
预热和预热效应对激光焊接有重大影响,但国内外
0前言
却罕见铝合金预热激光焊接硏究的报道。预热带来
的温度上升可以提高金属材料对激光的吸收率、
激光焊接较传统的焊接方法在工艺和加工效降低所需激光功率,谓节焊缝凝固时温度分布,延
率方面具有较大优势。但激光焊接的应用受激光器长熔池凝固时间,调节晶粒大小及分布等。本文研
功率等级、装配条件、过程控制及材料的高反射率究了预热铝合金搭接激光焊的焊缝成形、组织和力
等诸多因素限制。因此,利用其他焊接方法特点来学性能
弥补激光焊接不足的复合焊接技术就成为研究重
点。预热在复合激光焊接中起着重要作用习。虽然1激光焊试验方法及方案
国家自然科学基金资助项目(50575091)。20080308收到初稿,
20080903收到修改稿
试验装置如图1所示。电阻加热器的加热范围