How to Harden Aluminum
Aluminum is widely valued for its excellent strength-to-weight ratio, corrosion resistance, and ease of fabrication. However, in many structural or high-load-bearing applications, its naturally soft and ductile state is insufficient. To meet demanding mechanical requirements, various hardening techniques can be applied depending on the alloy series and end-use application. These methods enhance aluminum’s strength, wear resistance, and performance in critical environments.
In this article, we explore three primary methods to harden aluminum — work hardening, precipitation hardening, and solid solution strengthening.
Work Hardening (Strain Hardening)
Best for: Non-heat-treatable alloys such as 1xxx, 3xxx, and 5xxx series
Work hardening involves mechanically deforming the aluminum, such as through cold rolling, drawing, bending, or pressing. This plastic deformation increases dislocation density within the aluminum’s microstructure, impeding further dislocation movement and thereby improving hardness and yield strength. While this method is cost-effective and straightforward, it also reduces ductility, and overworking may cause cracking.
Alloys hardened through this method are classified with “H” tempers, such as H32 (strain hardened and stabilized) or H112 (strain hardened without specific control).
Precipitation Hardening (Heat Treatment)
Best for: Heat-treatable alloys such as 2xxx, 6xxx, and 7xxx series
Precipitation hardening, also called age hardening, is a thermal process involving solution heat treatment, rapid quenching, and controlled aging. During aging, fine particles (precipitates) form and block dislocation motion, greatly enhancing mechanical strength. This is the most effective hardening method for high-performance aluminum applications.
AMSpec offers in-house heat treatment including precision T6, T651, T73, and T76 tempers. We specialize in processing high-strength alloys like 6061, 6082, 7050, and 7075 for aerospace, defense, and industrial applications requiring superior strength, dimensional stability, and stress corrosion resistance.
Solid Solution Strengthening
Best for: Alloys requiring balanced strength and corrosion resistance
This method introduces alloying elements such as magnesium, zinc, or copper into the aluminum matrix, where they remain dissolved. These atoms distort the lattice structure and hinder dislocation movement. Though this method does not achieve the same strength as precipitation hardening, it offers a good trade-off between strength, corrosion resistance, and formability.
Why Choose AMSpec?
At AMSpec, we combine decades of technical experience with full in-house production capabilities — including extrusion, tube drawing, heat treatment, and precision finishing. Whether you need aircraft-grade structural tubes or custom profiles tailored to mechanical performance, we provide material solutions that meet your exact specifications. Let our team help you select the right alloy and hardening method to ensure long-term reliability and optimal strength.
