Aluminum alloy is an important industrial material, which is made by fusing aluminum with other elements. Its excellent properties, such as low density, high thermal conductivity and electrical conductivity, and good processing adaptability, have laid the foundation for its wide application. In order to give full play to its advantages in the production process, accurately grasping the melting point of aluminum alloy is the core prerequisite for formulating reasonable processes and selecting appropriate equipment.

What is Aluminum Alloy？

Aluminum alloy is a material made by mixing aluminum with other elements—like copper, magnesium, silicon, zinc, or manganese—to improve its strength, durability, and performance.

While pure aluminum is soft and flexible, aluminum alloys are designed to be much stronger and more suitable for engineering, construction, and manufacturing applications.

Composition & Classification of Aluminum Alloys

1 Series Aluminum Alloy: Copper is the main alloying element, and the copper content is generally between 3%-5%. It has high strength and good conductivity.

2 Series Aluminum Alloy: Copper is the main alloying element, and the copper content is generally between 3%-5%. It has high strength and good conductivity.

3 Series Aluminum Alloy: Manganese is the main alloying element, and the manganese content is generally between 1.0%-1.5%. It has good rust resistance and processability.

4 Series Aluminum Alloy: Silicon is the main alloying element, and the silicon content is usually between 4.5%-13.5%. It has high strength and good welding performance.

5 Series Aluminum Alloy: Magnesium content is the main feature, and the magnesium content is usually between 3%-5%. It has good formability, weldability and medium strength.

6 Series Aluminum Alloy: Magnesium and silicon are the main alloying elements, which can be strengthened by heat treatment and have good processability and corrosion resistance.

7 Series Aluminum Alloy: Zinc, magnesium, copper and other elements are the main components, and it is one of the strongest series in aluminum alloy.

8 series aluminum alloy: includes other alloy systems except 1 to 7 series, usually containing special elements such as lithium and iron, and the performance can be customized.

What is the melting point of aluminum alloy?

Aluminum melts at 660 °C (1,220 °F). This relatively low melting point (compared to steels) makes aluminum easy to cast and weld for industrial processes. The metal is lightweight (density ~2.7 g/cm³, about one-third that of steel), highly corrosion-resistant (it forms a protective oxide film), and an excellent conductor of heat and electricity.

Key Properties:

Lightweight: ~2.7 g/cm³ (≈1/3 the weight of steel).

Corrosion-Resistant: Natural oxide layer prevents rust.

Thermal/Electrical Conductivity: High thermal conductivity (~237 W/m·K) and low electrical resistivity.

Aluminum Alloy Surface Finishing Options

Sandblasting finish

Sandblasting uses high-speed sand flow to impact the surface of aluminum alloy to achieve cleaning and roughening. When sandblasting is applied to aluminum parts, it can effectively improve the surface cleanliness of the workpiece and form the required roughness, thereby improving its mechanical properties. This not only enhances the fatigue resistance of the workpiece, but also significantly improves the adhesion between the substrate and the coating, thereby extending the service life of the coating.

Brushed Finish

Aluminum wire drawing is a process that forms lines on the surface by directional sandpaper grinding. According to the texture effect, it can be divided into straight lines, random lines, spiral lines and threaded wire drawing. This process can accurately present a delicate and uniform silk texture, making the metal surface present a matte texture and a unique hair-like luster, giving the product a visual effect that combines modernity and technological aesthetics.

Anodizing

It is an electrochemical oxidation process for metals or alloys, which refers to the process of forming an oxide film on the surface of aluminum products (anodes) by using external current under specific electrolyte and process parameters. This process can not only improve the shortcomings of low hardness and easy wear of aluminum surface, but also significantly extend its service life and improve its appearance. It has become the core link of aluminum surface treatment and is also the most widely used and effective process.

Aluminum alloy Comparative with other materials

Aluminum alloy vs stainless steel:

Density: Aluminum ≈2.7 g/cm³ vs steel ≈7.8 g/cm³ (aluminum is much lighter).

Strength: High-strength aluminum alloys can reach 500-700MPa, and ultra-high-strength steel can reach >1000MPa or even 2000MPa (steel is usually stronger, but has an advantage over aluminum in strength).

Stiffness: The elastic modulus of steel (≈200GPa) is about three times that of aluminum (≈70GPa).

Corrosion resistance: Stainless steel (especially austenite) is usually much better than aluminum alloy (depending on surface treatment and alloy system), and aluminum alloy needs protection in specific environments.

Thermal and electrical conductivity: Aluminum is much better than stainless steel (especially austenite).

Thermal expansion: The CTE of aluminum is higher than that of stainless steel.

Cost: The raw material cost of aluminum is usually higher than that of carbon steel, but lower than that of stainless steel; the processing cost (such as forming and cutting) of aluminum may be lower; the reduction of system cost brought by lightweighting is the key.

Processability: Aluminum alloys are usually easier to form (extrusion, stamping), while stainless steel is more difficult to cut.

Weldability: Welding of aluminum alloys (especially high-strength alloys) is challenging (oxidation, hot cracking, softening), while stainless steel has better weldability (but austenite has a tendency to hot cracking).

Non-magnetic: All aluminum alloys are non-magnetic, austenite in stainless steel is non-magnetic, and ferrite/martensite is magnetic.

High temperature performance: Stainless steel (especially austenitic and ferritic heat-resistant steel) is far superior to conventional aluminum alloys.

Appearance: Both can be diversified (polishing, coloring, coating).

Aluminum alloy vs. magnesium alloy

Magnesium is lighter (≈1.74g/cm³), has equivalent or slightly lower strength, lower stiffness, generally worse corrosion resistance (requires strict protection), higher cost, good processability (especially casting), better damping, and poor high temperature performance.

Aluminum alloys vs. titanium alloys

Titanium has high strength (≈ high-strength steel levels), medium density (≈4.5g/cm³), excellent corrosion resistance, and good high-temperature performance, but is extremely expensive and difficult to process.

Aluminum alloys vs. engineering plastics/composites

Plastics/composites can be lighter (partially), have greater design freedom, good corrosion resistance, and are insulators, but are generally lower in strength/stiffness (except for high-performance composites), have poor heat resistance, are prone to aging, and are more complicated to recycle. Research hybrid structures (aluminum + composites).

Aluminum Alloy Application

Aluminum alloys are widely used in architectural decoration and daily life due to their unique properties, such as light weight, strong corrosion resistance and excellent strength-to-weight ratio. With the development of advanced aluminum alloys and new manufacturing technologies, the application fields of aluminum alloys are constantly expanding, becoming the most widely used type of non-ferrous metal structural materials.

Structural materials for building facades, windows, doors, and curtain walls are often required to maintain stable properties in complex working environments, such as rain, wind, and sunlight. Because a protective oxide layer forms on the surface of aluminum alloys, they are lighter and more corrosion-resistant than ordinary carbon steel; one of the most significant advantages of using aluminum alloys in buildings is that they can be easily molded into complex designs while maintaining a certain degree of strength, making them ideal materials for building exterior walls, bridges, and hard shells.

(aluminium alloy sections)

(aluminum alloy dome)

(Aluminum alloy pedestrian bridge)

(Aluminum alloy cover - Tesla Model S)

Summary

If you are looking for aluminum alloy products or you have a project related to aluminum alloy and stainless steel, contact Sucelsteel to meet your needs. We offer a variety of colors and finishes, a variety of material thicknesses to choose from, and custom sizes are also available. For more product information, or to get a free sample immediately, please send an email to contact@sucelsteel.com or call us at 0086 15017779517.

FAQ

What is the melting point of aluminum alloy?

Most aluminum alloys melt between 475°C to 660°C depending on their composition.

Is aluminum alloy better than stainless steel for windows?

Yes, aluminum is lighter and more corrosion-resistant, making it ideal for architectural use.

Does anodizing aluminum affect its melting point?

No, anodizing alters the surface but not the alloy's core melting temperature.

Can aluminum alloy be welded easily?

Some aluminum alloys are harder to weld due to oxidation and hot cracking; surface prep is key.