7. Some Common Questions and Solutions to Issues
1. How to Get Awesome Surface Finishes on Aluminum?
First, you should choose the type of finishing that suits the purposes of the component being manufactured. Typically, options are mechanical finishes, pretreatment, bright dipping, anodizing, liquid paint, powder coating, and sublimation.
Some of the finishing may not suit a particular aluminum component because they may not meet your specifications.
You should consider all the minor nuances that accompany every type of finishing. Pay attention to the sharpness of a cutting tool. It should not be dull, so always monitor the state of your CNC machine tooling. Choose the appropriate cutting tool geometry, which suits a particular CNC machine and a component being manufactured.
In case you have chosen the correct finishing, all that’s left is to conduct the process with all the safety precautions.
Pay attention to the sharpness of a cutting tool. It should not be dull, so always monitor the state of your CNC machine tooling. Another item is the burr sticky on the part, don’t forget to remove the burr in the process.
2. Why Does Aluminum Turn Brown When Milling?
Frequently, aluminum turns brown or even black when machined. The typical cause is oxidation, as aluminum is prone to reacting with the surroundings.
You should ensure that the metal is not exposed to extra moisture. Additionally, we recommend you replace the coolant. Cleaning machined parts with hot soapy water may also help to reduce the probability of oxidation.
3. What is Coating for Milling Aluminum?
A manufacturer may choose from several options to mill aluminum. First, it is uncoated tolling. It may still provide solid performance but can quickly deteriorate over time.
Then, it is gold-colored ZrN (Zirconium Nitride) tooling, which is considered non-expensive but enhances the properties of tooling significantly.
Finally, there are various titanium nitride (TiN) based coatings. Examples are titanium carbo-nitride (TiCN), titanium aluminum nitride (TiAIN), and others. They are better overall and offer to improve tooling with various extra features and properties. Such as wear, temperature, and oxidation resistance, improved sharpness or hardness, etc.
4. Should You Use Oil When Milling Aluminum?
The term “oil” in CNC machining refers to aluminum alloy cutting fluid, in a broad sense. It enhances the precision of cutting tools and improves the finishing outcomes.
Considering that the fluid is not expensive and significantly increases the quality of milling, you definitely should use it.
5. How Do You Fixture Mill Thin Wall Aluminum?
The significant concern associated with milling is that thin sheet metals would be cut through if milled. Common fixtures do not work well in this case, as they do not solve the problem.
If you do not want the surface of the worktable to be partly milled as well, you need to take precautions. Here are two tips:
- Support a sheet metal with a few more layers. So, they can be milled simultaneously. It may slightly deteriorate dimensions, but the thing is that you may use regular fixtures. And surfaces will not be cut. Then, just put the under milled workpiece on the top of the next stack, and you are good to go.
- Use MDF or plywood. Just fix a workpiece on a wooden block so it is milled instead of your precious surfaces. In a few attempts, you will know how many parts can be processed without changing a block. MDF is also an option, but it may reduce tool life, in case a cutting tool is not sustainable to abrasives.
- Use the tape. If the problem is to fix a part, just use double-sided tape to hold the part to a block of wood or raw aluminum.
6. How Thin Can Aluminum Be Machined?
Machining thin aluminum can be a challenging process, but with the right tools and techniques, it’s possible to produce high-quality parts with extremely thin walls. Using methods such as casting, fabrication, and CNC machining, aluminum parts can be created with walls as thin as 0.001 inches. Achieving this level of precision requires careful control of the machining process to prevent deformation and ensure the integrity of the final product.
7. What is the Easiest Aluminum to Machine?
One of the easiest aluminum alloys to machine is Aluminum 6061-T6. This alloy is widely recognized for its versatility and is often the standard grade offered by most manufacturing companies for CNC machining. Aluminum 6061-T6 is not only easy to machine but also highly adaptable, allowing for different heat treatments to enhance its properties further. Its excellent mechanical properties, combined with good corrosion resistance and a high strength-to-weight ratio, make it an ideal choice for a wide range of applications. Whether you are working on a small-scale project or industrial manufacturing, Aluminum 6061-T6 provides reliable performance and ease of machining.