What are architectural aluminum profiles?

Building products fabricated from aluminum and aluminum alloy materials are generally manufactured via a series of processes. Raw aluminum is first processed into castings, forgings, foils, sheets, strips, tubes, rods and profiles, followed by cold bending, sawing, drilling, assembly, surface coating and other procedures to form finished products.

Pure aluminum features low tensile strength, which limits its application scope. By adding small amounts of one or multiple alloying elements such as magnesium, silicon, manganese, copper, zinc, iron, chromium and titanium, aluminum alloys with differentiated performance can be produced. Subjected to cold working and heat treatment, aluminum alloys gain further strengthening and hardening with drastically elevated tensile strength.

The standard electrode potential of aluminum stands at -1.67 V. With highly active chemical properties, aluminum readily reacts with oxygen in the air to form a firm, dense oxide film, granting it excellent corrosion resistance under normal atmospheric conditions and clean water. However, galvanic corrosion will occur when aluminum comes into contact with steel or other metallic materials. Corrosion also takes place in humid environments when aluminum touches alkaline substances including concrete, cement mortar and lime, as well as wood and soil. Appropriate anti-corrosion treatment is therefore mandatory.

Aluminum alloys are categorized into cast aluminum alloys and wrought aluminum alloys by manufacturing processes. Wrought aluminum alloys are predominantly adopted in the construction sector, which can be rolled into sheets, foils and strips, or extruded into rods, tubes and profiles with various complex cross-sections. Wrought aluminum alloys are further divided into anti-rust aluminum alloys, duralumin, super duralumin and special aluminum alloys based on performance and application requirements. Construction applications mainly cover commercially pure aluminum (L1–L6), anti-rust aluminum alloys (LF2, LF21, etc.) and forged aluminum alloys (LD2).

The most prominent merit of aluminum and its alloys lies in their density, approximately one-third that of steel, while their specific strength (ratio of ultimate tensile strength to density) can match or exceed that of structural steel. In addition, aluminum and aluminum alloys can be easily machined into diverse shapes and adapt to various connection techniques, enabling the adoption of the most economical and rational cross-section forms for building structures.

The application of aluminum alloys greatly reduces building dead load and material consumption, cuts down transportation and installation workload of components, and accelerates construction progress. The economic benefits are particularly remarkable in seismic zones, mountainous areas and remote regions with poor transportation access. Aluminum and aluminum alloys boast attractive appearance, superior corrosion resistance, high reflectivity to light and heat, and favorable sound absorption performance. A wide range of color finishes can be achieved through chemical and electrochemical treatments. For these reasons, aluminum materials are widely used in industrial and civil buildings for roofing, wall cladding, doors and windows, structural frames, interior and exterior decorative panels, ceilings, balustrades and handrails, indoor furniture, retail display cabinets, construction formwork and more.

The construction industry ranks among the three largest markets for aluminum materials, consuming roughly 20% of the global total aluminum output. In some industrialized developed countries, construction aluminum consumption accounts for over 30% of national aluminum production. In recent years, construction aluminum products have undergone continuous upgrades, with rising annual adoption of innovative building products including color-coated aluminum sheets, composite aluminum panels, composite door and window frames, and aluminum alloy formwork. In China, aluminum alloys have been widely applied to roofing, wall surfaces, doors and windows in industrial and civil construction, and their utilization has gradually expanded to interior & exterior decoration and construction formwork, yielding satisfactory practical results.