Forming Challenges of Replacing Copper with Aluminum in Heat Exchangers
Why is replacing copper with aluminum gradually a trend in the air conditioning industry?
In 2026, the price of raw material copper has risen to about 18%, which brought enormous stress to the traditional air conditioner manufacturing regarding copper in the core position.
Advantages in manufacturing with aluminum materials:
Lower Raw Material Costs: Copper is significantly more expensive than aluminum. Because raw materials will have a substantial influence on the production cost of an air conditioner, changing to aluminum lets manufacturers protect profit margins.
Lighter weight making up for air conditioners: Aluminum weights are far less than copper. It's easier to move, handle, and install air conditioners that are lighter, and they put less stress on buildings and mounting frames. More lightweight air conditioning systems facilitate transportation, handling, and installation while exerting reduced structural strain on structures and mounting brackets.
Resistance to Formicary Corrosion: Conventional copper piping in air conditioning systems is susceptible to early deterioration due to formicary corrosion (minute pinhole leaks triggered by organic acids and lubricants). Instead, aluminum is naturally resistant to this particular sort of corrosion.
Innovative Engineering Technology: Modern all-aluminum microchannel heat exchangers use flat tubes with short parallel pathways rather than spherical copper pipes. These designs achieve high heat transfer efficiency while employing less material by weight.
Difficulty in mechanical forming and processing:
a) Lack of accurate control of size. When there is bending or stamping, make it much easier to wrinkle, flatten, or produce micro-cracks because of the poor ductility of aluminum.
b) Cause damage to the structure. Thermal stress, the linear expansion coefficient of aluminum is large, and the thermal expansion and contraction are serious during the alternation of cold and heat, which can easily lead to structural deformation or loose joint surface.
c) High requirements for micro-channel forming. The porous thin-walled flat tube is extremely dependent on high-precision mold and process control when it is extruded, shaped, and assembled with fins.
Limits on the welding and connection process
1. The welding temperature place is quite narrow: Due to the low melting point of the aluminum and the high-level surface oxide film’s melting point, it can easily lead to overburning and collapse of the base metal or cold welding during brazing.
2. Difficult connection of dissimilar metals: Direct contact between copper and aluminum is easy to cause galvanic corrosion, which requires friction welding, flash butt welding, or special coating, and the process is complex and the defective rate is high.
Physical and service performance defects compensate for:
1. Inherently insufficient heat conduction efficiency: the thermal conductivity coefficient is only 60% of that of copper, which needs to be compensated by complex design such as strengthening internal teeth, optimizing fins, or increasing the windward side.
2. Poor corrosion resistance under harsh working conditions: pitting and perforation are easy to occur in salt spray or industrial environments, so surface treatment processes such as zinc spraying or anticorrosive coating must be added.
Cost‑saving and lightweight promote copper‑to‑aluminum replacement, while forming and reliability challenges restrict large‑scale popularization. Continuous process optimization is essential for wider industry adoption.
