Surreal illustration of sodium interacting with a magnesium alloy.

Unlock Stronger Metals: The Surprising Secret of Magnesium Alloys

Soraya Malik in Tech & Innovation June 2025 • 3 min read.

"Discover how a tiny addition of sodium can dramatically improve the strength and durability of magnesium alloys, revolutionizing industries from aerospace to automotive."

In the world of materials science, the quest for stronger, lighter, and more durable materials is never-ending. Precipitation hardening, a technique used to strengthen cast products, relies on elements like aluminum, tin, zinc, calcium, and neodymium. Among these, tin stands out due to its significant solubility difference between high and low temperatures, offering substantial hardening potential.

Magnesium alloys, known for their lightweight properties, have become increasingly popular in various industries. Researchers have been exploring ways to enhance their strength and durability through various alloying techniques. One promising avenue involves the addition of tin (Sn) to magnesium-aluminum (Mg-Al) alloys. However, the precipitation behavior of these complex alloys is not fully understood, particularly concerning the role of sodium (Na).

New research sheds light on how a small amount of sodium can dramatically improve the properties of magnesium-aluminum-tin-zinc alloys. This discovery could pave the way for stronger, lighter materials in aerospace, automotive, and other industries.

The Magic of Sodium: Refining Magnesium Alloys

Surreal illustration of sodium interacting with a magnesium alloy.

The study, dives into the effects of sodium on the microstructure and hardening response of Mg-Al-Sn-Zn alloys. The team investigated alloys with varying compositions, including ATZ821 (Mg-8Al-2Sn-0.7Zn-0.2Mn) and ATZ651 (Mg-6Al-5Sn-0.7Zn-0.2Mn), with and without sodium.

The researchers found that adding a small amount of sodium (0.03 wt%) to these alloys led to a remarkable increase in hardness and a significant decrease in the time it takes to reach peak hardness during artificial aging. This means the materials not only become stronger but also reach their maximum strength faster.

Here's how sodium makes a difference:

Refined Microstructure: Sodium refines the size and distribution of Mg17Al12 and Mg2Sn precipitates within the alloy matrix.
Faster Hardening: It accelerates the precipitation kinetics, allowing the alloy to reach peak hardness quicker.
Increased Strength: The overall hardness and strength of the alloy are significantly improved.

The study revealed that sodium refines both Mg17Al12 and Mg2Sn precipitates. These precipitates play a crucial role in hardening the alloy. Mg17Al12 precipitates form first, and then Mg2Sn precipitates nucleate at the edges of the Mg17Al12 precipitates. Sodium helps to create smaller, more evenly distributed precipitates, leading to enhanced strength.

A Brighter Future for Magnesium Alloys

This research opens up new possibilities for designing high-performance magnesium alloys with enhanced strength and durability. By understanding the role of sodium in refining the microstructure and accelerating precipitation kinetics, engineers can tailor these materials for specific applications in aerospace, automotive, and other industries where lightweight and strong materials are essential. Future studies will delve deeper into the mechanisms behind sodium's influence on precipitate formation, paving the way for even more advanced magnesium alloys.

About this Article -

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This article is based on research published under:

DOI-LINK: 10.1007/978-3-319-52392-7_31, Alternate LINK

Title: Precipitation Behavior Of Mg–Al–Sn–Zn–(Na) Alloy

Journal: The Minerals, Metals & Materials Series

Publisher: Springer International Publishing

Authors: Su Mi Jo, Yohan Go, Bong Sun You, Young Min Kim

Published: 2017-01-01

Everything You Need To Know

How does adding sodium impact the strength and hardness of magnesium alloys?

The addition of just 0.03 wt% of sodium to Mg-Al-Sn-Zn alloys, like ATZ821 (Mg-8Al-2Sn-0.7Zn-0.2Mn) and ATZ651 (Mg-6Al-5Sn-0.7Zn-0.2Mn), results in a refined microstructure with smaller and more evenly distributed Mg17Al12 and Mg2Sn precipitates. This leads to accelerated precipitation kinetics and a significant increase in the alloy's overall hardness and strength.

In what way does sodium refine the microstructure of magnesium alloys, and why is this refinement important?

Sodium refines the microstructure of magnesium alloys by influencing the size and distribution of Mg17Al12 and Mg2Sn precipitates. Specifically, it helps create smaller, more evenly dispersed precipitates within the alloy matrix. This enhanced distribution is crucial because these precipitates hinder dislocation movement, the primary mechanism of plastic deformation, thereby strengthening the material.

Does this research explore the impact of sodium on magnesium alloys containing elements like calcium or neodymium, or does it primarily focus on Mg-Al-Sn-Zn alloys?

The study focuses on the effects of sodium on Mg-Al-Sn-Zn alloys, specifically ATZ821 (Mg-8Al-2Sn-0.7Zn-0.2Mn) and ATZ651 (Mg-6Al-5Sn-0.7Zn-0.2Mn). While the research highlights significant improvements with the addition of sodium, it primarily explores the relationships between magnesium, aluminum, tin and zinc. Other alloying elements, such as calcium and neodymium, are not explicitly investigated in the context of sodium's influence in this particular study. These other elements might offer alternative or complementary strengthening mechanisms, but their interaction with sodium in magnesium alloys would require further research.

What are the potential implications of using sodium-enhanced magnesium alloys in industries like aerospace and automotive?

The enhanced strength and durability of magnesium alloys, achieved through the addition of sodium and the refinement of Mg17Al12 and Mg2Sn precipitates, have profound implications for industries where lightweight yet strong materials are critical. In the aerospace industry, this could lead to lighter aircraft components, resulting in improved fuel efficiency. Similarly, in the automotive industry, lighter vehicles could improve gas mileage and reduce emissions. The use of stronger magnesium alloys could also extend the lifespan of components, reducing maintenance costs and improving overall product reliability.

How does precipitation hardening, specifically involving Mg17Al12 and Mg2Sn precipitates, contribute to the overall strength of magnesium alloys?

Precipitation hardening strengthens magnesium alloys by introducing secondary phases, such as Mg17Al12 and Mg2Sn precipitates, within the magnesium matrix. These precipitates act as obstacles to dislocation movement, which is how metals deform. When a force is applied, these dislocations encounter the precipitates and must either cut through them or bypass them. Both processes require additional energy, thus increasing the strength and hardness of the alloy. The even distribution and fine size of these precipitates, facilitated by the addition of sodium, are crucial for maximizing this strengthening effect.