Essential difference between copper-aluminum composite and cast iron radiator

Copper-aluminum composite radiator is the composite technology of copper tube and aluminum plate, and the connection technology of header and waterway. A radiator is made of two kinds of materials: deoxidized copper tube, and the radiating part is a new aluminum alloy. After hydraulic tube expanding, the copper tube and aluminum fin are closely combined, which fully combines the corrosion resistance of copper tube and the good heat dissipation effect of aluminum fin. What we see is that these residents ignore that the expansion coefficients of different metals are different, so all composite gold radiators have thermal attenuation. The principle of mechanical expansion joint is to use an expansion core with a diameter slightly larger than the inner diameter of the copper tube, generally 0.3-0.6 mm in diameter. Under the drag of the oil cylinder or chain, the copper tube will undergo radial plastic deformation through the whole length of the copper tube, and then it will have an interference fit with the aluminum wing. In actual production, mechanical expansion joint highlights two major disadvantages: the front and inner wall of copper tube are scratched by expansion core, even a slight scratch may cause great damage to copper tube. Secondly, the radial springback of the copper tube causes the copper tube and aluminum wing to fall off. This is the reason why the copper-aluminum composite radiator does not feel as hot as before after several years of use. Different from cast iron radiator, copper-aluminum composite radiator is light, but copper is expensive, which is not convenient for large-scale promotion and production. Aluminum is afraid of alkali corrosion, its expansion coefficient is relatively small, and it is not easy to stick after internal anti-corrosion treatment. Moreover, the thin copper tube directly affects the heat dissipation effect and is easy to block. Cast iron radiator adopts rare earth cast iron, which is economical and practical. The single piece is made of resin sand core, the inner cavity is smooth and sand-free, and the outer surface is electrostatically sprayed with plastic, which is corrosion-resistant. It can be applied to any water quality and external environment, and the bearing capacity reaches 2.0Mpa, which meets the requirements of high-rise buildings for high bearing capacity. Large water storage capacity, large water flow, good heat dissipation effect and strong thermal insulation, which is more cost-effective than copper-aluminum composite radiator. There will be no safety problems caused by different expansion coefficients of metals and different adhesion of two metals.