Current Status and Application of Aluminum Alloy Building Materials

Aluminum alloy, as a high-quality, high specific strength lightweight structural material, has developed over more than a century to become the second largest metal material globally after steel in terms of usage. Especially since the mid-20th century, aluminum alloy has shifted massively from military to civilian use, widely applied in various fields of national production, becoming an indispensable important material in the foundation of the national economy. Traditional building materials such as concrete and steel are greatly limited in some fields due to their heavy weight, poor durability, and inferior mechanical properties. As a new type of building material with multiple excellent properties, aluminum alloy plays an increasingly important role in today's economic and social development.

1 Concept

Aluminum alloy refers to a class of alloys with aluminum as the base metal. The main alloying elements include copper, silicon, magnesium, zinc, and manganese, while minor alloying elements include nickel, iron, titanium, chromium, lithium, etc. Aluminum alloy is the most widely used non-ferrous metal structural material in industry, extensively applied in construction, aviation, aerospace, automotive, machinery manufacturing, shipbuilding, and chemical industries.

2 Performance Characteristics

Compared with steel and concrete materials, aluminum alloy as a new type of building material has many excellent properties that traditional building materials do not possess. It is lightweight, has high specific strength, good corrosion resistance, and low-temperature resistance. Replacing steel or concrete with aluminum alloy can greatly reduce the structural self-weight. Due to the lighter upper structure, it not only reduces construction intensity and shortens the construction period but also lowers foundation requirements and reduces the construction cost of the lower structure. Zhang Xinming et al. [1] studied the composition design, smelting, homogenization, solution treatment, quenching, pre-stretching, and aging processes of large-size high-strength aluminum alloy materials. Modern aluminum alloy materials are developing towards lightweight, high strength, large size, high uniformity, and material/structure integration, which is also a hot topic in high-strength aluminum alloy science and engineering research. Under atmospheric influence, aluminum alloy surfaces can naturally form an oxide layer that largely prevents corrosion. Analysis of aluminum alloy corrosion under marine microorganism SRB action shows that protective measures such as polyurethane or polyurea coatings are necessary when aluminum alloy is used in marine engineering. Studies have found that as temperature decreases, both tensile strength and yield strength increase, with tensile strength increasing more significantly, and no brittle-ductile transition occurs due to yield strength approaching tensile strength. With decreasing temperature, strength and elongation do not decrease but increase, making it suitable for manufacturing building structures in cold northern regions [4].

3 Architectural Applications

Aluminum alloy building materials are mainly used for building doors and windows, curtain walls, interior and exterior decoration, thermal insulation aluminum profiles, and structural purposes.

3.1 Aluminum Alloy Profiles for Glass Curtain Walls

With the increasing popularity of curtain walls in China's construction sector, various materials for curtain walls have attracted attention from all sectors of society. Among them, glass curtain walls currently dominate the market in China due to their integrity, elastic connections, lightweight, and ease of construction, making them widely used. Aluminum alloy profiles are one of the main materials used in the construction of glass curtain walls.

3.2 Aluminum Alloy Decorative Panels

As a rapidly emerging new type of interior and exterior wall decoration material in China, aluminum alloy decorative panels combine the advantages of aluminum alloy sheets, high-quality insulation materials, and thermal spray plastic technology. Since the decorative panels are processed from aluminum alloy thin sheets through thermal spray plastic embossing, forming, and cutting, they have great applicability and can be customized according to site requirements, greatly saving profiles and reducing waste of edge materials.

3.3 Thermal Insulation Aluminum Profiles

Thermal insulation strip aluminum profiles are composed of aluminum alloy profiles combined with thermoplastic composite insulation strips; roll-pressed thermal insulation aluminum alloy profiles use high-density polyamide 6788 strips or rigid PVC plastic strips with good insulation properties, processed by strip insertion and rolling; foam thermal insulation aluminum profiles connect inner and outer aluminum profiles with insulation strips to form an integrated unit, filling the formed insulation cavity with polyurethane foam, creating a "cold bridge" for thermal insulation and energy saving. Thermal insulation aluminum alloy profiles are a new type of insulation material with great development potential.

3.4 Structural Aluminum Profiles

Steel is one of the widely used structural materials in civil engineering, but steel bridges have long been troubled by durability issues caused by poor corrosion resistance [8]. In contrast, aluminum alloy has many advantages such as low density, high strength-to-weight ratio, corrosion resistance, good weldability, low maintenance costs, and recyclability, attracting increasing interest and attention in structural engineering.

4 Development Direction

Adjusting product structure and increasing the output of high-performance products are key development directions for China's aluminum processing materials. In the future, the aluminum alloy building materials industry will see a gradual reduction in the number of small enterprises, intensified mergers and acquisitions, achieving group and large-scale operations. The comprehensive competitiveness of enterprises focusing on scale, technology, brand, management, and service will become increasingly important; product structure adjustment will increase the proportion of industrial profiles and high-end energy-saving building profiles; the advantages of the industrial chain will increasingly influence the market, with extrusion enterprises accelerating development upstream or downstream. On one hand, they will integrate the upstream industrial chain to reduce costs; on the other hand, they will actively cooperate with downstream aluminum product enterprises to manufacture finished products based on aluminum alloy building materials through deep processing, implementing an aluminum product value-added strategy.

5 Summary

Aluminum alloy has excellent mechanical properties, low-temperature resistance, durability, and excellent processing performance, with wide applications. Whether as decorative or structural materials, it plays an irreplaceable role. China's aluminum alloy building materials have entered a new period of rapid development, and the application of aluminum alloy building materials is becoming increasingly widespread globally. At present, aluminum alloy remains the primary consumer industry for building materials in China, which aligns with China's national conditions. With the continuous development of China's economic and social construction and the deepening research on aluminum alloy building materials by researchers, aluminum alloy will play a greater role in broader fields.