扁线电机紫铜端子激光焊接模拟与工艺优化

曹国麟; 耿韶宁; 蒋平; 舒乐时; 马涛; 周溢飞

doi:10.12073/j.hjxb.20240125005

扁线电机紫铜端子激光焊接模拟与工艺优化

华中科技大学, 机械科学与工程学院, 制造装备数字化国家工程研究中心, 武汉, 430074

基金项目: 国家自然科学基金资助项目(U22A20196，52188102)；广东省基础与应用基础研究基金资助项目(2023A1515010081)；华中科技大学“交叉研究支持计划”项目(2024JCYJ001)

详细信息

作者简介:
曹国麟，男，硕士；研究方向为激光扫描焊接；Email: 18867413789@163.com

通讯作者:
耿韶宁，助理研究员；Email: sngeng@163.com.

中图分类号: TG 456.7
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出版历程
- 收稿日期: 2024-01-24
- 网络出版日期: 2025-03-17
- 刊出日期: 2025-04-24

Simulation and process optimization of laser welding for flat wire electric motor copper terminals

National Engineering Research Center for Manufacturing Equipment Digitization, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China

摘要

摘要:
采用数值模拟的方法对紫铜端子激光焊接过程中复杂的熔池流动行为和气孔的形成及抑制机制展开了深入的研究. 文中建立了激光扫描焊接传热 — 流动耦合模型，探索了扫描轨迹对焊缝熔深和接合面积的影响，阐明了接头气孔生成及抑制机制，基于响应面法预测接头机械剥离力并优化焊接参数. 结果表明，椭圆线轨迹下激光束能量能够更稳定的在匙孔壁面和匙孔底部传递，使得焊缝平均熔深和接合面积更大. 匙孔深度和温度梯度是影响气孔生成的主要因素，椭圆线轨迹的焊缝气孔体积小，且生成位置相对焊缝位置存在偏移，气孔对接头性能影响小. 针对椭圆线轨迹的焊接参数优化后，激光束能量向匙孔底部转移，使得焊缝和接头区域的平均熔深较大. 优化后焊接参数为椭圆线轨迹，激光功率为4224 W，扫描幅度为2.5 mm，比例为3∶1，扫描圈数为3，接头机械剥离力达到779.6 N，与定点焊相比提高了 126%.
- 数值模拟 /
- 扁线电机 /
- 紫铜端子 /
- 激光焊接 /
- 响应面法
Abstract:
A numerical simulation method was employed to carry out an in-depth study on the complex molten pool flow behavior and the formation and inhibition mechanisms of porosity in the laser welding process of copper terminals. A coupled heat transfer–flow model of laser scanning welding was established, and the effect of scanning trajectory on depth of fusion and joint area was explored. The generation and inhibition mechanisms of joint porosity were clarified, and the mechanical peeling force at the joint based on the response surface method was predicted, with the welding parameters optimized. The results show that the laser beam energy can be transmitted more stably in the keyhole wall and the bottom of the keyhole under the elliptical line trajectory, resulting in a larger average depth of fusion of the weld and joint area. The depth of the keyhole and the temperature gradient are the main factors affecting the generation of porosity, and the volume of the porosity of the weld under the elliptical line trajectory is small. The generation position is shifted with respect to the position of the weld so that the porosity has little effect on the performance of the joint. After the optimization of welding parameters for elliptical line trajectory, the laser beam energy is transferred to the bottom of the keyhole, which makes the average depth of fusion of the weld and joint area larger. The optimized welding parameters yield an elliptical line trajectory, laser power of 4 224 W, scanning amplitude of 2.5 mm, ratio of 3:1, number of scanning circles of 3, and mechanical peeling force at the joint of 779.6 N, which is 1.26 times higher than that of fixed-point welding.
- numerical simulation /
- flat wire motor /
- copper terminals /
- laser welding /
- response surface method

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图 1 焊接试验平台

Figure 1. Welding experimental platform

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图 2 机械剥离测试试样(mm)

Figure 2. Peeling test specimen

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图 3 网格模型(mm)

Figure 3. Mesh model

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图 4 试验与模拟结果对比(mm)

Figure 4. Comparison of experimental and simulation results

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图 5 定点焊熔池波动

Figure 5. Spot welding molten pool fluctuations. (a) t₀; (b) t₀ + 12 ms; (c) t₀ + 24 ms; (d) t₀ + 36 ms; (e) t₀ + 48 ms; (f) t₀ + 60 ms; (g) t₀ + 72 ms

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图 6 定点焊接头焊缝区域温度分布

Figure 6. Temperature distribution in the weld of spot weld. (a) 125 ms; (b) 150 ms

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图 7 椭圆线轨迹熔池波动情况

Figure 7. Elliptical line trajectory welding molten pool fluctuations. (a) t₀; (b) t₀ + 12 ms; (c) t₀ + 24 ms; (d) t₀ + 36 ms; (e) t₀ + 48 ms; (f) t₀ + 60 ms; (g) t₀ + 72 ms

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图 8 椭圆线轨迹焊缝温度分布

Figure 8. Temperature distribution in the weld of elliptical line trajectory. (a) 125 ms; (b) 150 ms

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图 9 不同扫描轨迹焊缝熔深分布

Figure 9. Distribution of weld penetration depth for different scanning trajectories

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图 10 不同扫描轨迹气孔分布

Figure 10. Distribution of porosity under different scanning trajectories

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图 11 A型气孔形成机制

Figure 11. Formation mechanism of type A porosity. (a) t₀; (b) t₀ + 0.6 ms; (c) t₀ + 1.2 ms; (d) t₀ + 1.8 ms

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图 12 B型气孔形成及抑制机制

Figure 12. Formation and suppression mechanism of type B porosity. (a) t₀; (b) t₀ + 0.6 ms; (c) t₀ + 1.2 ms; (d) t₀ + 1.8 ms; (e) t₀ + 2.4 ms; (f) t₀ + 6.0 ms; (g) t₀ + 6.6 ms; (h) t₀ + 7.2 ms

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图 13 接头宏观形貌

Figure 13. Macroscopic of the joint

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表 1 TU1紫铜主要化学成分

Table 1 Chemical compositions of TU1 copper

Cu	P	Bi	Sb	As	Fe	Ni	Pb	S	余量
≥99.97	≤0.002	≤0.001	≤0.002	≤0.002	≤0.004	≤0.002	≤0.003	≤0.004	≤0.009

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表 2 TU1紫铜热物性参数

Table 2 Thermal physical properties of TU1 copper

固相比热容 γ_s/(J·(kg·K)⁻¹)	液相比热容 γ_l/(J·(kg·K)⁻¹)	固相热导率 c_s/(W·(m·K)⁻¹)	液相热导率 c_l/(W·(m·K)⁻¹)	固相线温度 T_s/K	液相线温度 T_l/K	熔化潜热 ΔH_s/(kJ·kg⁻¹)
385	469	380	150	1380	1250	209

蒸发潜热 ΔH_l/(kJ·kg⁻¹)	液相线表面张力 σ₁/(N·m⁻¹)	表面张力梯度 (dσ/dT)/(N·(m·k)⁻¹)	动力粘度 μ/(Pa·s)	饱和蒸气压 P_v/MPa	蒸发温度 T_v/K	初始温度 T₀/K
4730	1.257	0.0002	0.004	0.1013	2835	300

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表 3 试验方案及对应的响应值

Table 3 Experimental design and corresponding response values

编号	扫描幅度 A/mm	比例 S	扫描圈数 f	机械剥离力 F/N
1	1	1	4	464.7
2	3	1	4	365.8
3	1	3	4	465.8
4	3	3	4	602.0
5	1	2	3	531.2
6	3	2	3	478.5
7	1	2	5	555.9
8	3	2	5	431.6
9	2	1	3	492.3
10	2	3	3	768.5
11	2	1	5	501.1
12	2	3	5	619.6
13	2	2	4	645.9
14	2	2	4	657.8
15	2	2	4	689.4
16	2	2	4	704.1
17	2	2	4	616.8

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表 4 模型方差分析

Table 4 Model analysis of variance

来源	平方和 S_S(10⁻⁹)	自由度 D_F	均方 M_S(10⁻⁹)	组内差异 F	差异显著性 P
拟合模型	2203.000	9	2203.000	22.16	0.0002
A	84.380	1	84.380	7.64	0.0279
S	598.900	1	598.900	54.22	0.0002
f	22.100	1	22.100	2.00	0.2001
AS	284.900	1	284.900	25.79	0.0014
Af	24.180	1	24.180	2.19	0.1825
Sf	30.340	1	30.340	2.75	0.1414
A²	945.200	1	945.200	85.58	< 0.0001
S²	147.900	1	147.900	13.39	0.0081
f²	5.451	1	5.451	0.49	0.5051
	R²			0.9661
	Adj.R²			0.9225

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