The key difference between heat-treatable and non-heat-treatable alloys is that heat-treatable alloys are made by heat treatment followed by the addition of alloying elements, whereas non-heat-treatable alloys are made by the addition of alloying elements followed by heat treatment processes.
Heat-treatable alloys are mixtures of metallic and nonmetallic components consisting of pure aluminum that is heated up to a certain point. Non-heat-treatable alloys are aluminum alloys that are combined with alloying elements before any heat treatment.
CONTENTS
1. Overview and Key Difference
2. What are Heat-treatable Alloys
3. What are Non-heat-treatable Alloys
4. Heat-treatable vs Non-heat-treatable Alloys in Tabular Form
5. Summary – Heat-treatable vs Non-heat-treatable Alloys
What are Heat-treatable Alloys?
Heat-treatable alloys are mixtures of metallic and nonmetallic components consisting of pure aluminum that is heated up to a certain point, followed by the addition of alloying elements homogenously. The addition of the alloying material makes the aluminum become solid. However, this mixture is still at a high temperature which is then quenched through rapid cooling. The rapid cooling can cause atoms of the alloy elements to freeze in place.
Usually, heat-treatable aluminum alloys form when the aluminum atoms and alloy element atoms tend to combine during a natural aging process at room temperature. Sometimes, this is achieved by artificial aging in a furnace set at a low temperature.
According to the Aluminum Association Administers, heat-treatable alloy materials are made with different alloying elements. This makes them classified into different specific groups. These classifications are named using 4-digit numbers. The alloying material used for the alloy is indicated by the first digit. The second digit gives the modifications made to the base alloy material while forming this alloy. The last two digits indicate the minimum aluminum content in the alloy. The most common groups come as 2xxx, 6xxx, and 7xxx.
For heat-treatable 2xxx aluminum alloys, copper is used as the alloying material. In 6xxx heat-treatable aluminum alloys, the alloying material used is silicon or magnesium, or both. Moreover, in 7xxx heat-treatable aluminum alloy, we use zinc as the alloying element.
What are Non-heat-treatable Alloys?
Non-heat-treatable alloys are aluminum alloys that are combined with alloying elements before any heat treatment. Initially, the strength of these alloys is achieved by the addition of other elements. There are different types of non-heat-treatable alloys, including pure aluminum alloys, manganese alloys, silicon alloys, and magnesium alloys. The further increase in the strength of this type of alloy is obtained by various types of cold working and strain hardening processes.
The most common cold working and strain hardening methods include rolling, drawing through dies, stretching, or similar operations that we can obtain an area reduction. The final properties of the alloy are determined by the total reduction in the area of the material. Moreover, “stabilizing” is an elevated temperature process that can ensure that final mechanical properties do not change over time.
What is the Difference Between Heat-treatable and Non-heat-treatable Alloys?
Heat-treatable alloys are mixtures of metallic and nonmetallic components consisting of pure aluminum that is heated up to a certain point. Non-heat-treatable alloys are aluminum alloys that are combined with alloying elements before any heat treatment. The key difference between heat-treatable and non-heat-treatable alloys is that heat-treatable alloys are made through heat treatment followed by the addition of alloying elements, whereas non-heat-treatable alloys are made through the addition of alloying elements followed by heat treatment processes.
The below infographic presents the differences between heat-treatable and non-heat-treatable alloys in tabular form for side by side comparison.
Summary – Heat-treatable vs Non-heat-treatable Alloys
Heat-treatable alloys are mixtures of metallic and nonmetallic components consisting of pure aluminum that is heated up to a certain point. Non-heat-treatable alloys are aluminum alloys that are combined with alloying elements before any heat treatment. The key difference between heat-treatable and non-heat-treatable alloys is that heat-treatable alloys are made through heat treatment followed by the addition of alloying elements, whereas non-heat-treatable alloys are made through the addition of alloying elements followed by heat treatment processes.
Reference:
1. “Heat Treatable Aluminum Alloy Series.” Belmont Metals, 11 Jan. 2018.
Image Courtesy:
1. “Alloy, rim, aluminum, tire, machine, wheel, vehicle, car, steel, chrome” (CC0) via Pixino
2. “MITRPAK aluminum alloy housing” By Whoisjohngalt (CC BY-SA 4.0) via Commons Wikimedia
