CLADDING TECHNOLOGY SHANXI CO., LTDMIG Welding of Profile Radiators and Conducting Busbars
Literature Overview
This 1991 publication by Sheng Changyuan, Gao Yongyue, and Zhao Min from the Tianjin Welding Research Institute, published in Welding Technology, addresses the practical challenges of MIG welding for profile radiators and electrical conducting busbars. These components serve dual functions in electrical power systems, combining thermal management with high-current electrical conduction, making weld quality critical for both mechanical integrity and electrical performance.
Core Technical Points
The study examines the welding process development for aluminum alloy profile radiators and copper or copper-alloy conducting busbars using MIG (GMAW) welding. The unique challenge lies in achieving joints that provide both adequate mechanical strength and low electrical resistance, as weld quality directly affects the thermal and electrical performance of the assembled component.
Welding Process Parameters
| Parameter | Profile Radiator Welding | Conducting Busbar Welding |
|---|---|---|
| Wire diameter | 1.0-1.2 mm | 1.2-1.6 mm |
| Welding current | 180-250 A | 250-350 A |
| Travel speed | 300-500 mm/min | 200-400 mm/min |
| Shielding gas | Ar or Ar-5%CO2 | Pure Ar |
| Heat input range | 0.8-1.5 kJ/mm | 1.5-3.0 kJ/mm |
| Typical joint design | Lap or fillet | Butt or lap |
Key Welding Challenges
For profile radiators, the primary challenges include maintaining fin alignment during welding, preventing thermal distortion of thin fins, and ensuring complete fusion without burn-through. The thin aluminum alloy fins (typically 0.3-0.8 mm) are highly susceptible to warpage and distortion from welding heat input. For conducting busbars, the critical requirements are minimum electrical resistance at the weld joint and maximum current-carrying capacity without local overheating.
Defect Analysis and Countermeasures
| Defect Type | Root Cause | Countermeasure |
|---|---|---|
| Porosity | Moisture in shielding gas or wire | Dry storage, gas flow control |
| Burn-through | Excessive heat input on thin fins | Reduce current, increase speed |
| Distortion | Asymmetric thermal input | Balanced weld sequence, fixturing |
| High resistance joint | Incomplete fusion, oxide inclusion | Pre-cleaning, proper gas coverage |
| Cracking | Residual stress in high-strength alloys | Lower heat input, post-weld stress relief |
Engineering Practice Implications
The welding of electrical components requires a different quality focus compared to structural welding. While structural welds are evaluated primarily on mechanical strength and dimensional accuracy, electrical welds must also meet electrical resistance specifications. Engineers should incorporate electrical resistance testing into the acceptance criteria for busbar joints, typically requiring weld resistance to be within 10-20% of the base metal resistance.
Quality Control Requirements
- Visual inspection for complete fusion and absence of surface defects
- Electrical resistance measurement across weld joints using four-wire (Kelvin) method
- Mechanical pull testing for lap joints to verify bond strength
- Dimensional inspection of fin alignment and profile geometry
- Thermal cycling testing to verify joint integrity under operating temperature variations
Key Reflections
This study highlights an important aspect of welding engineering that is often underemphasized in general welding literature: the multiplicity of performance requirements that can apply to a single weld joint. In electrical component welding, the weld must simultaneously satisfy mechanical, electrical, and thermal performance criteria. The MIG welding process offers the flexibility to adjust parameters for different joint configurations and material combinations, but requires careful process optimization for each specific application. The experience documented in this 1991 publication remains relevant for modern electrical component manufacturing, demonstrating that fundamental welding principles and process optimization methodologies have enduring value regardless of technological advancement. Engineers working on electrical busbar and radiator assemblies should approach process development with a systematic FMEA methodology to identify and mitigate risks across all performance domains.