Raytron Technical Review RESEARCH ARTICLE WP-01-06

Clad Welding Process: Core Technology for Bimetallic Bonding

Q: What are the main steps of clad welding process?

Main steps include: 1) Material preparation (cleaning copper strip and core); 2) Copper strip wrapping and forming; 3) Longitudinal seam welding; 4) Multi-pass drawing; 5) Intermediate annealing; 6) Final dimension drawing; 7) Quality inspection. Each step requires precise parameter control.

Q: How to avoid common defects in clad welding?

Delamination: increase welding temperature and pressure; Cracking: add intermediate annealing, control work hardening; Eccentricity: adjust cladding alignment, ensure uniform copper wrapping; Interface defects: control atmosphere, prevent oxidation. Regular equipment maintenance and raw material inspection.

RAYTRON技术团队¹ *

¹RAYTRON集团技术研究中心, 中国

^*Corresponding author

Received: 2025年12月 Accepted: 2026年2月 Published: 2026年3月

DOI: 10.1234/raytron.2026.WP-01-06

Abstract

包覆焊接是生产高质量双金属导体的关键制造技术。本Whitepapers详细研究包覆焊接工艺，包括材料准备、焊接参数、拉拔工艺和界面形成机制。我们分析工艺参数对结合质量的影响，提出优化策略，并提供常见缺陷的故障排除指南。

Key Findings

Clad Welding is Core Technology Clad welding produces high-quality bimetallic conductors by wrapping copper strip around the core material and creating metallurgical bonding. Unlike electroplating, clad welding produces permanent metallurgical bonding.
Process Parameters Determine Bond Quality Welding temperature, pressure, and speed are key parameters affecting bond quality. Optimal welding temperature for CCA is 300-400°C, welding speed 5-20m/min, and pressure must ensure tight contact between copper strip and core.
Drawing Process Achieves Precision Forming Multi-pass drawing process forms the clad-welded composite rod into final dimensions, with single-pass reduction rate of 15-25% and total reduction rate up to 85-95%. Intermediate annealing controls work hardening.
Quality Control Throughout Process From raw material inspection to finished product testing, quality control spans the entire production process. Key indicators include interface bond strength, conductivity, dimensional tolerance, and surface quality.

Keywords

包覆焊接;双金属结合;CCA制造;工艺参数;界面质量;拉拔工艺

1. 引言

包覆焊接是生产双金属导体的核心技术，通过将铜带包覆在芯材周围并进行冶金结合，实现两种金属的永久连接。

创建包覆焊接过程动画

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Video 1 包覆焊接过程动画

2. 材料准备

2.1 芯材准备

芯材Surface必须清洁、无氧化，以确保良好的结合。

2.2 包覆材料准备

铜带需要经过清洗、脱脂和Surface活化处理。

3. 焊接工艺

3.1 焊接参数

焊接温度、压力和速度是影响结合质量的关键参数。

3.2 焊接方式

主要采用氩弧焊或激光焊进行铜带纵缝焊接。

4. 拉拔工艺

4.1 拉拔道次设计

4.2 加工硬化控制

需要通过中间退火控制加工硬化程度。

5. 界面形成

界面形成包括：初始接触、扩散开始、金属间化合物形成、稳定结合。

6. 工艺优化

通过实验设计（DOE）方法优化工艺参数。

7. 故障排除

8. 结论

包覆焊接工艺是双金属导体生产的核心技术，通过优化工艺参数可以获得高质量的冶金结合。

Frequently Asked Questions

What is the fundamental difference between clad welding and electroplating?

Clad welding produces metallurgical bonding with bond strength >150MPa, layer thickness 20-200μm, and excellent high-temperature performance. Electroplating is mechanical adhesion with bond strength <50MPa, layer thickness typically <10μm, and easy delamination under thermal cycling. Clad welding products have permanent bonding.

What are the main steps of clad welding process?

Main steps include: 1) Material preparation (cleaning copper strip and core); 2) Copper strip wrapping and forming; 3) Longitudinal seam welding; 4) Multi-pass drawing; 5) Intermediate annealing; 6) Final dimension drawing; 7) Quality inspection. Each step requires precise parameter control.

How to avoid common defects in clad welding?

Delamination: increase welding temperature and pressure; Cracking: add intermediate annealing, control work hardening; Eccentricity: adjust cladding alignment, ensure uniform copper wrapping; Interface defects: control atmosphere, prevent oxidation. Regular equipment maintenance and raw material inspection.

Figures

创建包覆焊接工艺流程图

Fig. 1 包覆焊接工艺流程图

创建铜带包覆铝杆横Cross-Section示意图

Fig. 2 铜带包覆铝杆横Cross-Section示意图

创建焊接温度对结合强度的影响曲线

Fig. 3 焊接温度对结合强度的影响曲线

创建拉拔道次设计示意图

Fig. 4 拉拔道次设计示意图

创建界面形成过程示意图

Fig. 5 界面形成过程示意图

常见缺陷SEM照片

Fig. 6 常见缺陷SEM照片

Tables

Table 1 工艺参数范围

参数	CCA	CCS	NCC
焊接温度 (°C)	300-400	400-500	350-450
焊接速度 (m/min)	5-20	3-15	5-15
拉拔减径率 (%)	15-25	10-20	15-22

Table 2 原材料要求

材料	纯度	Surface要求	Dimensional Tolerance
铜带	≥99.9%	无氧化、无油污	±0.02 mm
铝杆	≥99.5%	清洁、干燥	±0.1 mm
钢杆	低碳钢	除锈、清洁	±0.1 mm

Table 3 焊接参数优化

参数	低值	最优	高值
温度 (°C)	280	350	420
压力 (MPa)	150	250	350
速度 (m/min)	5	12	20

Table 4 拉拔道次设计

道次	入口直径 (mm)	出口直径 (mm)	减径率 (%)
1	10.0	8.5	28
2	8.5	7.2	28
3	7.2	6.1	28
4	6.1	5.2	27

Table 5 常见缺陷及解决方案

缺陷	原因	解决方案
分层	结合不良	提高焊接温度
裂纹	过度加工硬化	增加退火
偏心	包覆不均匀	调整对中

References

ASTM International ASTM B566-04: Standard Specification for Copper-Clad Aluminum Wire ASTM (2020)
ASM International Welding Handbook ASM International (2021)
Raytron Technical Report Clad Welding Process Optimization Internal Report TR-2025-032 (2025)

Authoritative References

ASTM International IEC (International Electrotechnical Commission) ISO (International Organization for Standardization) SAE International IEEE