Differences of Aluminum-Plated Sheet, Aluminum-Zinc-Plated Sheet, and Galvanized Sheet

In the realm of coated steel materials, the distinctions among aluminum-plated sheets, aluminum-zinc-plated sheets, and galvanized sheets are quite evident.

Aluminum-Plated Sheet: An aluminum-plated sheet refers to a steel sheet with an aluminum-silicon alloy coating, comprising 90% aluminum and 10% silicon.

Aluminum-Zinc-Plated Sheet: An aluminum-zinc-plated sheet features a surface coating composed of 55% aluminum, 43.5% zinc, and trace amounts of other elements.

Galvanized Sheet: A galvanized sheet is characterized by a zinc coating on the steel surface.

Performance Comparison

DistinctionAtmospheric Corrosion ResistanceHigh-Temperature Oxidation ResistanceProcessing PerformanceWeldabilityCoating PerformanceEdge ProtectionCathodic Protection Effect
Galvanized Steel CoilBetterGoodGoodGoodGoodGoodStrong
Aluminum-Plated CoilExcellentExcellentExcellentPoorGoodPoorPoor
Aluminum-Zinc-Plated CoilExcellentExcellentGoodGoodGoodGoodStrong

Differences Between Galvanized Sheet and Aluminum-Zinc-Plated Sheet

When both sides of a 55% aluminum-zinc alloy-coated steel sheet are exposed to the same environment, it exhibits superior corrosion resistance compared to a galvanized steel sheet of the same thickness. The aluminum-zinc-coated sheet not only demonstrates excellent corrosion resistance but also offers outstanding adhesion and flexibility for color-coated products.

The primary distinction between galvanized sheets and aluminum-zinc-plated sheets lies in the composition of the coating. Galvanized sheets uniformly distribute a layer of zinc material on the surface, providing an anodic protective effect. In contrast, the surface coating of aluminum-zinc-plated sheets consists of 55% aluminum, 43.5% zinc, and other elements, forming a honeycomb structure. While the aluminum-zinc coating also provides an anodic protective effect, the reduced zinc content and the aluminum encapsulation make the anodic protection less effective. Therefore, when aluminum-zinc-plated sheets are cut, the exposed edges quickly corrode, emphasizing the importance of minimizing cutting and applying rust-resistant or zinc-rich paint to protect the edges.

Aluminum-Plated Steel Sheet

Known as “hot-dip aluminum-plated steel sheet,” it shares manufacturing similarities with hot-dip galvanized steel sheets. However, its heat resistance surpasses that of galvanized steel sheets.

Five Characteristics of Aluminum-Plated Sheet

  1. High-Temperature Resistance: Forming an iron-aluminum alloy with a specific combination of base material and coating structure, aluminum-plated sheets exhibit exceptional resistance at high temperatures, ensuring high reflectivity up to 450°C.
  2. Thermal Reflectivity: At 480°C, aluminum-plated sheets can reflect 80% of incident heat, making them suitable for efficient heat barriers or reflectors in high-temperature applications.
  3. Mechanical Strength: At room temperature, the mechanical strength of aluminum-plated sheets matches that of their base material. At the same high temperature of 480°C, the strength of aluminum-zinc-coated sheets is ten times that of aluminum sheets, allowing for a 30% reduction in sheet thickness.
  4. Corrosion Resistance: During hot-dip galvanizing, the molten aluminum immediately reacts with oxygen in the air to form a protective layer of Al2O3, ensuring rapid passivation of the steel sheet surface. This protective layer is stable, insoluble in water, and possesses self-healing properties even if the surface is scratched.
  5. Ecological Characteristics: Chemically untreated aluminum-plated sheets have no adverse effects on health, making them suitable for food processing. Numerous tests by professional organizations confirm their harmlessness to humans, making them environmentally friendly. Aluminum-plated sheets are fully recyclable, offering performance comparable to stainless steel at approximately one-third of the cost.

Applications

Aluminum-Plated Sheet

  1. Automotive and motorcycle mufflers, exhaust pipes, and fuel tanks.
  2. Combustion furnaces, heat exchangers, dryers, and air conditioning units.
  3. Household appliances such as water heaters, gas stoves, bread boxes, chimneys, microwaves, food processing machinery, electric ovens, and cookware.
  4. Building components like roof panels, walls, ceilings, and other heat-insulating parts.

Galvanized Sheet

  1. Construction industry: Light steel keels, corrugated sheets, ventilation ducts, floor load-bearing plates, prefabricated houses, roofing, and wall cladding for factory roofs and walls, and municipal engineering enclosure boards.
  2. Used as a substrate for downstream products.
  3. Home appliance industry: Shells and bottom plates for appliances such as air conditioners, refrigerators, washing machines, microwaves, water heaters, and computer casings.
  4. Automotive industry: Car bodies, exterior panels, interior panels, floor panels, and doors.
  5. Other industries: Storage and transportation, packaging, grain silos, chimneys, buckets, ship bulkheads, lithium-ion battery, etc.

Aluminum-Zinc-Plated Sheet

  1. Building: Roofing, walls, garages, soundproof walls, pipes, and prefabricated houses.
  2. Automotive: Mufflers, exhaust pipes, wiper accessories, fuel tanks, and more.
  3. Home appliances: Backplates for refrigerators, gas stoves, air conditioners, electronic microwaves, LCD frames, CRT explosion-proof belts, LED backlight sources, electrical cabinets, etc.
  4. Agriculture: Pigsties, chicken coops, grain silos, pipes for greenhouses, etc.
  5. Others: Heat-insulating covers, heat exchangers, dryers, water heaters, etc.

In conclusion, the distinctive properties of aluminum-plated sheets, galvanized sheets, and aluminum-zinc-plated sheets make each type suitable for specific applications. The choice depends on factors such as corrosion resistance, thermal conductivity, and intended use, emphasizing the importance of selecting the