Magnesium alloy structure undergoing T5 heat treatment

Unlock Stronger Magnesium: How Heat Treatment Can Revolutionize Metal Profiles

Lena Kashyap in Tech & Innovation September 2025 • 4 min read.

"Exploring T5 Heat Treatment Effects on AZ80 Hollow Profiles and the Future of Lightweight Materials"

In an era defined by the relentless pursuit of lightweight yet robust materials, magnesium alloys have emerged as frontrunners, captivating industries ranging from automotive to aerospace. Their appeal lies in a unique blend of low density, exceptional strength-to-weight ratios, and remarkable machinability. Among these alloys, the AZ80 stands out, offering a compelling balance of moderate strength and cost-effectiveness.

Hollow profiles, essential components in lightweight designs, are frequently manufactured through a process called porthole-die extrusion. This method involves dividing the metal into multiple streams, which are then rejoined in a welding chamber, inevitably creating extrusion welds. These welds have traditionally been considered the Achilles' heel of hollow profiles, often being the first point of failure under stress.

A recent study published in 'Materials and Manufacturing Processes' sheds new light on how T5 heat treatment can significantly enhance the properties of extrusion welds in AZ80 hollow profiles. This research paves the way for broader applications of magnesium alloys, particularly in scenarios demanding high structural integrity.

What is T5 Heat Treatment and Why Does It Matter for Magnesium Alloys?

Magnesium alloy structure undergoing T5 heat treatment

T5 heat treatment is a specific aging process applied to alloys to enhance their mechanical properties after extrusion. It involves heating the material to a specific temperature and holding it there for a set period, allowing microstructural changes to occur that increase strength and hardness. For AZ80 magnesium alloy, this process is crucial in optimizing its performance characteristics.

The study meticulously examined the impact of various T5 heat treatments on AZ80 hollow profiles, focusing on the behavior and microstructure of extrusion welds. Researchers observed a fascinating transformation in the morphology of β-Mg17Al12, a key strengthening phase, within the weld regions under different temperature conditions. Five distinct morphologies were identified, each influencing the material's overall properties.

Optimized Hardness: Contrary to common belief, extrusion welds are not necessarily the weakest link. The study found that the hardness of weld regions could equal or even surpass that of weld-free regions after T5 treatment.
Microstructural Control: The key lies in carefully controlling the heat treatment parameters. Aging at 200°C for 24 hours emerged as the most effective, achieving excellent mechanical properties while minimizing the formation of precipitate-free zones (PFZs).
PFZ Management: PFZs, areas depleted of strengthening precipitates, often form near weld interfaces during aging. These zones can compromise the material's strength. The optimized T5 treatment effectively reduces the width of PFZs, enhancing overall durability.

These findings challenge conventional assumptions about the vulnerability of extrusion welds and open up exciting possibilities for utilizing AZ80 alloy in more demanding applications. By fine-tuning the T5 heat treatment process, manufacturers can unlock the full potential of this lightweight material.

The Future of Magnesium Alloys: Stronger, Lighter, and More Reliable

This research marks a significant step forward in understanding and optimizing the properties of magnesium alloys. By demonstrating the effectiveness of T5 heat treatment in enhancing extrusion weld strength, it paves the way for wider adoption of AZ80 alloy in critical applications. As industries continue to seek lighter, stronger, and more sustainable materials, advancements in magnesium alloy technology will play a pivotal role in shaping the future of engineering and manufacturing.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1080/10426914.2016.1232816, Alternate LINK

Title: Effects Of T5 Heat Treatment On Extrusion Welds In Az80 Hollow Profile

Subject: Industrial and Manufacturing Engineering

Journal: Materials and Manufacturing Processes

Publisher: Informa UK Limited

Authors: Gaoyong Lin, Yuyong Wei, Ke Zhou, Hongyang Wang, Weiyuan Song

Published: 2016-12-05

Everything You Need To Know

What is T5 heat treatment, and how does it improve AZ80 magnesium alloy?

T5 heat treatment is an aging process applied to alloys like AZ80 to enhance their mechanical properties after extrusion. It involves heating the material to a specific temperature and holding it for a set period, which causes microstructural changes that increase strength and hardness. Specifically for AZ80 magnesium alloy, this process optimizes its performance characteristics. The study highlighted how T5 treatment significantly enhances the properties of extrusion welds in AZ80 hollow profiles by controlling the morphology of the strengthening phase β-Mg17Al12 within the weld regions.

Why are extrusion welds a critical area of focus when working with AZ80 hollow profiles?

Extrusion welds are a focal point because they have traditionally been considered the weakest points in hollow profiles. The process of porthole-die extrusion, used to create these profiles, involves rejoining multiple streams of metal in a welding chamber, leading to these welds. Under stress, these welds are often the first to fail. The research emphasizes that with proper T5 heat treatment, the hardness of weld regions can equal or even surpass that of weld-free regions, making them less of a vulnerability.

How does T5 heat treatment affect the microstructure of AZ80 magnesium alloy, particularly at the welds?

T5 heat treatment influences the microstructure by causing changes in the strengthening phase β-Mg17Al12 within the weld regions. The study identified five distinct morphologies of this phase, each impacting the material's overall properties. The key is to carefully control the heat treatment parameters, such as the temperature and duration. For example, aging at 200°C for 24 hours was found to be the most effective, leading to excellent mechanical properties. This process also helps manage the formation of precipitate-free zones (PFZs), which can compromise the material's strength.

What are precipitate-free zones (PFZs), and why is their management important in T5 heat treatment of AZ80?

PFZs are areas depleted of strengthening precipitates that often form near weld interfaces during the aging process. These zones can reduce the material's strength and durability. In the context of T5 heat treatment for AZ80, effective management of PFZs is crucial. The optimized T5 treatment, such as aging at 200°C for 24 hours, effectively reduces the width of PFZs, thereby enhancing the overall durability and performance of the material, particularly in critical applications.

How might the advancements in T5 heat treatment for AZ80 impact the future of industries like automotive and aerospace?

The advancements in T5 heat treatment for AZ80 magnesium alloy can significantly impact industries like automotive and aerospace by enabling the use of stronger, lighter, and more reliable materials. By enhancing the strength of extrusion welds, the research paves the way for wider adoption of AZ80 alloy in critical applications. This is particularly relevant as these industries continually seek to reduce weight while maintaining or improving strength and performance, which can lead to more fuel-efficient vehicles and lighter aircrafts, ultimately contributing to sustainability and efficiency goals.