Heat Treating Aluminum Parts: Benefits and Methods

Heat treating is a process used to alter the physical and mechanical properties of metals. Aluminum is a popular material choice for many industries because it’s lightweight and corrosion resistant. Heat treating aluminum parts is a common practice to increase the strength, hardness, and ductility of the metal.

Heat treating aluminum parts involves heating the material and holding it at a specific temperature for a certain period of time. This process can achieve different results depending on the desired outcome.

For example, heat treating can be used to soften the metal for easier machining or to harden it for increased strength and durability.

Heat treating can significantly improve the properties of the metal and make it more suitable for a variety of applications. Proper heat treatment can also extend the lifespan of the parts and reduce the risk of failure. This article will help you understand the basics of heat treating aluminum parts.

Why Heat Treat Aluminum Parts

Aluminum parts are often heat treated to improve their strength, durability, and resistance to wear and tear.

Here are some of the benefits of heat treating:

• Improved strength: Heat treating can significantly increase the strength of aluminum parts, making them more resistant to bending and cracking. This is especially important in the aerospace, automotive, and construction industries, where parts need to withstand high stress and loads.
• Better wear resistance: Heat treating improves the wear resistance of aluminum parts, making them less prone to damage from friction, abrasion, and corrosion. This is important in applications where parts are exposed to harsh environments, such as marine and offshore industries.
• Enhanced machinability: Heat treating is typically a secondary process, done after machining. It can make aluminum parts easier to machine by reducing the hardness and improving the surface finish. This saves time and manufacturing costs, and also improves the accuracy and precision of the finished parts.
• Controlled distortion: Heat treating can also be used to control the distortion of aluminum parts, which happens due to uneven cooling or thermal stresses. By controlling the heating and cooling process, the distortion is minimized, resulting in parts that are more accurate and consistent in shape and size.

Heat Treating Process

The heat treatment process can be explained in several subsections: preparation, heating, soaking, quenching, and aging.

Preparation

Before the heat treatment process begins, the aluminum parts must be cleaned and prepped. This involves removing any surface contaminants, such as oil or grease, and ensuring that the parts are free from any defects or cracks. The parts are then placed in a furnace or heat treating oven.

Heating

Once the parts are in the furnace, they are heated to a specified temperature. The temperature and duration of the heating process will depend on the aluminum alloy and desired outcome. During the heating process, the aluminum parts will begin to soften and become more malleable.

Soaking

After the parts have been heated to the desired temperature, they’re “soaked” at that temperature for a specific amount of time. The heat penetrates the entire part and ensures that the desired properties are achieved. For smaller parts, this can take 10 minutes, and up to 12 hours for larger parts.

Quenching

After the soaking process, the parts are rapidly cooled by quenching them in a liquid or gas. This rapid cooling process is essential to lock in the desired properties and prevent the aluminum from returning to its original state.

Aging

Finally, the parts are “aged” by bringing them to a lower temperature for a specific amount of time. This aging process allows the aluminum to reach its final properties and improves its strength and hardness.

Applications of Heat Treated Aluminum Parts

Heat treating is an essential process for aluminum parts used in various industries, including aerospace, automotive, construction, and electronics. Heat treatment enhances the mechanical properties of aluminum, making the parts stronger, more durable, and resistant to wear. Here are some common applications of heat-treated aluminum parts:

Aerospace

Aluminum is commonly used in the aerospace industry for its lightweight, high strength, and corrosion resistance. Heat-treated aluminum parts are used in various aerospace applications, including:

• Structural components such as frames, wings, and fuselage
• Engine components such as fan blades, compressor blades, and turbine disks
• Interior components such as seats, overhead bins, and galleys

Heat-treated aluminum parts are critical for the safety and performance of aircraft, as they must withstand extreme temperature changes, pressures, and loads.

Automotive

Aluminum is increasingly used in the automotive industry because it’s lightweight and improves fuel efficiency. Heat-treated aluminum parts are used in various automotive applications, including:

• Engine components such as cylinder heads, pistons, and connecting rods
• Transmission components such as housings and gears
• Suspension components such as control arms, knuckles, and spindles

Using heat-treated aluminum parts in vehicles helps reduce weight, improve performance, and increase fuel efficiency.

Construction

Aluminum is also used in the construction industry for its lightweight, corrosion resistance, and aesthetic appeal. Heat-treated aluminum parts are used in various construction applications, including:

• Windows, doors, and curtain walls
• Roofing, siding, and decking
• Structural components such as beams, columns, and trusses

Heat-treated aluminum parts in construction provide durability, strength, and design flexibility.

Overall, heat-treated aluminum parts are essential for various industries and applications, providing strength, durability, and performance. The heat treating process ensures that aluminum parts meet the required mechanical properties and standards, enhancing their reliability and value.

Heat Treated vs Anodized Aluminum

Anodizing aluminum is a different finishing process that has similar benefits to heat treating. The anodizing process creates a thin layer of oxide on the part’s exterior. The oxide layer acts as a stronger, corrosion-resistant, and visually-appealing surface.

The primary difference between heat treating and anodizing parts is how the structure changes. Heat treating changes the entire structure of the part, while anodizing only adds a layer of protection to the outside of the part.

The treatment process that you choose depends on the purpose of the part and the environment it’s being used in.

Which aluminum finish should you choose?

Your choice of finish ultimately depends on how your part and product is going to be used. Heat treating, anodizing, and powder coating are both great finishing options for aluminum parts.

Heat treatment is often used for cast aluminum parts and cold rolled parts. This is ideal for increasing the strength of the parts, and benefits the entire part, rather than just treating the part’s surface.

Anodizing is ideal if you need to add a layer of protection while maintaining tight dimensions. You’ll get excellent corrosion and wear resistance, and have an attractive metallic look without increasing the size of your part too much. Anodizing is also the better choice when the part needs to dissipate heat, or if you’ll be using any glue or primer on it.

Powder coating is the better option when you want vibrant colors and unique textures that will last. The coating will last even when exposed to the outside elements. Powder coating also offers good protection at a lower cost than anodizing.

Spex is an ISO 9001:2015 certified precision machine shop in Rochester, NY.

We machine thousands of custom metal parts every month for different businesses around the world. Reach out to our team to see if we can help with your next project.