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Business SummaryAluminum characteristics

Aluminum's excellent properties are utilized in many fields.

Aluminum: 10 features

Aluminum is a metal featuring many outstanding properties. Here are 10 of them.

Lightweight

The specific gravity (density) of aluminum is 2.7 g/cm3 at 20°C. Compared to iron’s 7.8 g/cm3 and copper’s 8.9/cm3, the mass of aluminum for the same volume is about 1/3. This lightness can be used to improve product performance by reducing the weight of various parts, housings, and bodies. Aluminum is used in the field of transportation equipment such as automobiles, railcars, aircraft, and ships for the purpose of improving performance and conserving energy.

High corrosion resistance

Aluminum combines with atmospheric oxygen to form a dense and stable oxide film on its surface. This oxide film blocks moisture and thus enables excellent corrosion resistance. Aluminum alloys with enhanced corrosion resistance are used in construction, automobiles, ships, and other marine applications. However, corrosion will occur if part of the oxide film is destroyed. In such cases, surface treatment such as anodizing can be used to provide higher corrosion resistance.

Easy to form

Aluminum is easy to form into the desired shape. Aluminum foil can be rolled down to a few microns, and extruded aluminum can be freely designed into complex cross-sectional shapes.

High strength and toughness

Although the strength of pure aluminum is not high, it can be greatly increased by adding copper, manganese, silicon, magnesium, zinc, etc., to make an alloy, or by combining plastic working and heat treatment. Depending on the alloy and quality, tensile strength can be selected from 70 to 600 MPa.

High electrical conductivity

Aluminum is a very economical metal as a conductive material. Relative to copper, aluminum has an electrical conductivity of about 60%, but since its specific gravity is 1/3, it can conduct about twice as much current for the same weight. Because of this property, aluminum is used in almost all high-voltage transmission lines and its use is expected to grow in the fields of energy and electronics in the future.

High thermal conductivity

The thermal conductivity of aluminum is about three times that of iron. This property of aluminum allows it to be used in air conditioning and heating equipment, engine parts, various heat exchangers, beverage cans, etc., because of its ability to transfer heat well and cool quickly.

Excellent recyclability

Aluminum has a melting point of 660°C, lower than those of iron (1534°C) and copper (1083°C), and this property makes it highly valuable as scrap because it can be melted and recycled at low temperatures. Recycled ingots can be produced using only 3% of the energy of new ingots, and the beverage can recovery rate in Japan is over 90%. Our group has its own aluminum can recycling system, which contributes to the effective use of resources and reduction of waste.

Harmless, odorless, and hygienic

Aluminum is harmless, odorless, and hygienic. Even if aluminum is leached or forms compounds through some chemical reaction, it does not affect the human body or damage soil as heavy metals do. Because of this property, aluminum is widely used in food and pharmaceutical packaging, beverage cans, medical equipment, and household containers.

Reflects light and heat

Aluminum with a well-polished surface reflects visible light, as well as infrared and ultraviolet light, microwave radiation, and the electromagnetic waves in the radio band used for communication and radar, and thus it reflects heat. This property is used in reflectors, lighting fixtures, and other applications.

Non-magnetic

Aluminum is non-magnetic and thus is unaffected by magnetic fields. Combined with its other properties, its applications are expanding to include measuring instruments, electronic medical equipment, mechatronics equipment, and superconductivity-related equipment.