Skip to content 
Aluminum is a staple in modern manufacturing. It’s strong for its weight, and it’s used in everything from aerospace to consumer electronics. But machining aluminum has its own unique challenges, such as part deformation. This can affect the precision and quality of your final product, making it critical to manage when you’re running a CNC machine.
Table of Contents
Before we get into how to effectively prevent the deformation of aluminum parts during CNC machining, we need to understand why it happens in the first place. Aluminum is popular because of its light weight and strength, but it is also notorious for deforming during machining. If you don’t use the right machining techniques, not only will the quality of your finished product be compromised, but you will also waste a lot of time and material. Below, we will discuss some of the key operating parameters and techniques that you need to know in order to overcome these processing challenges and optimize your production process.
Optimal Cutting Parameters
Low Feed Rate: Slowing down the feed rate during machining reduces the force exerted on the aluminum, which decreases the stress and minimizes deformation. This is critical to keeping the part’s dimensions intact.
High Cutting Speeds: Using high cutting speeds helps to keep the heat down, which is essential for keeping the aluminum from getting soft during the machining process. Soft aluminum deforms easily, so it’s important to keep things cool.
Proper Depth of Cut: Instead of making deep cuts that put a lot of stress on the material, making multiple shallow cuts spreads the mechanical load more evenly. This not only keeps the aluminum from deforming but also extends the life of your cutting tools.
Tool Selection and Design
Sharp Tools: It is important that you use sharp tools and keep them sharp. Dull tools will pull and distort the material, causing it to move in a way you don’t want it to move.
Tool Materials and Coatings: Using tools with carbide or diamond coatings will help you cut faster and more accurately. These materials stay sharp longer, so you get consistent results and are less likely to distort the workpiece.
Clamping and Support Techniques
Even Clamping Pressure: A well-designed fixture that applies even clamping pressure will hold the workpiece without deforming it. Deformation is often caused by uneven clamping pressure, especially with softer metals like aluminum.
Additional Support Points: For large parts or parts with thin walls, adding additional support points around the workpiece can keep the part from bending or twisting due to cutting forces. This is critical to maintain part integrity throughout the machining process.
Controlling Machining Temperatures
Use Coolant: Coolant is critical for managing the heat generated during cutting. It helps carry away the heat generated during cutting to keep the aluminum from reaching temperatures that can soften and deform it.
Cool Down Periods and Not Cutting Continuously: If you are doing a lot of cutting, letting the aluminum cool down periodically or not cutting continuously will drastically reduce the heat generated. This is especially important on complex parts or when you are machining for a long time.
Advanced CNC Machines
Multi-axis CNC machines are advanced CNC machines that have the ability to machine complex parts without the need to reposition the workpiece multiple times. By allowing the cutting to occur from multiple angles, these machines reduce the need to move the workpiece, which helps to ensure that the workpiece remains stable and that there is less chance for the workpiece to deform.
Heat Treatments and Stress Relief
Annealing: One heat treatment that can be used to relieve internal stresses in the aluminum is annealing. This is useful because it can help to relieve the internal stresses that would otherwise cause the aluminum to deform during later stages of machining or when the part is in use.
Finishing: The final finishing processes are critical for achieving the desired dimensional accuracy and surface quality. By performing these processes after the material has stabilized, you can help to ensure that the part retains its shape and meets the requirements of the specification.
In conclusion, if you use these six strategies you can dramatically reduce part deformation in aluminum CNC machining, which will lead to better parts and more efficient production. By paying attention to cutting parameters, tooling, support mechanisms, and temperatures, you can overcome one of the biggest challenges of working with aluminum and make your overall machining life a lot easier.temperatures, manufacturers can overcome one of the primary challenges of working with aluminum and enhance their overall machining success.
