Aluminium tempering - strength through hardening

Heat treatment Aluminum tempering Nitrocarburizing Hardening and tempering, annealing Vacuum technology - soldering

Aluminum tempering

Aluminum is particularly popular in the aerospace and automotive industries due to its specific strength combined with its low volume.

Where low weight and good electrical and thermal conductivity are required, aluminum is the preferred choice.

Our employees have the necessary expertise to apply the various requirements in heat treatment processes.

Manufacturing temper "F" (undefined), "H" for work hardening, "O" soft annealed, or "T" are specifications for aluminum tempers. A component is always in temper T if it is not treated to temper F, H, or O. If you require strength data for your customers, we determine the mechanical values on our tensile testing machine and document this information in a 2.2 or 3.1 test certificate.

Is good formability or high strength in the hardened state important for your aluminum parts? We can produce these requirement profiles in our semi- and fully automated systems. A highly heated water basin for demanding components is also integrated into the automation process.

The process of aluminum tempering

1. Solution annealing

During solution annealing, the aluminum is heated to a specific temperature to fully incorporate the alloying elements into the metal lattice. This step ensures a homogeneous structure and forms the basis for the subsequent hardening steps.

2. Quenching

Immediately after solution annealing, the aluminum is rapidly cooled. Typically, a cold or hot water bath is used. The goal of this rapid quenching is to prevent the precipitation of alloying elements during cooling. Rapid cooling maintains the homogeneous solid solution achieved during solution annealing in a metastable state.

Unfortunately, undesirable vapor bubbles occur during quenching, impairing uniform cooling. These bubbles must be removed from the component surface by means of circulation.

3. Hardening

A) Artificial aging

Depending on the alloy, the material is held at a specific temperature between 90°C and 220°C for a specific time. This process, also known as "artificial aging," leads to a uniform precipitation of the alloying elements, which significantly improves the hardness and strength of the material. Compared to the cold aging process, artificial aging achieves higher strength values.

B) Cold aging

In addition to artificial ageing, some aluminum alloys use cold ageing, in which the material is stored below room temperature or slightly above. This process offers advantages in certain cases, such as increased toughness.

Aluminum tempering for compressor wheels

Shipping Turbocharger

Turbocharger aluminum tempering shipping

A special application for aluminum hardening and tempering is the treatment of compressor wheels in marine engine turbochargers. These components must withstand extreme mechanical and thermal stress without compromising performance. Targeted hardening of the aluminum alloys achieves high resistance to fatigue, corrosion, and wear, significantly increasing the service life and reliability of the turbochargers.

Increased strength and hardness

Tempering and hardening can significantly improve the mechanical properties of aluminum, making it ideal for use in components subject to extremely high stress.

Low weight with high load capacity

Despite being hardened, aluminum remains light and resilient – an important property for use in shipping, where weight savings are of great importance.

Corrosion resistance

The thermal treatment of aluminum alloys also improves their resistance to corrosion, which is essential in the maritime environment.

Adaptability to various aluminum alloys

Different alloys can be adapted to specific requirements through specific tempering processes. This allows both hardness and toughness to be precisely controlled.

Contact us!

Tel.: +41(0)58 588 5170

info@wbh-klingnau.ch

Wärmebehandlung Klingnau AG

Kanalstrasse 12
CH-5313 Klingnau

We advise you personally in our company and take time to address your individual requirements and questions.

Aluminium tempering: solution annealing, quenching and hardening