Best feeds and speeds for milling aluminum: How to set key parameters?

Aluminum is widely used in the aviation, automotive, mold, electronics and other industries due to its light weight, moderate strength, good corrosion resistance and easy processing. However, when processing, how to set the best feeds and speeds for milling aluminum is crucial.

If the parameters are not set properly, it will not only affect the processing efficiency, but also lead to reduced surface quality, increased tool wear, and even damage to the workpiece. This article will explore in depth the best feeds and speeds for milling aluminum, as well as the factors affecting feed and speed and the corresponding solutions.

1. Key factors affecting the best feeds and speeds for milling aluminum

(1) Aluminum type

There are many types of aluminum alloys, the most common of which are pure aluminum (such as 1xxx series) and aluminum alloys (such as 6xxx, 7xxx series). The mechanical properties of different aluminum materials vary greatly, which directly affects the setting of processing parameters. For example:

1xxx series (such as 1050, 1100): pure aluminum, low hardness, easy to process, but strong adhesion and easy to form built-up edge.

6xxx series (such as 6061, 6082): medium strength, good machinability, suitable for conventional milling.

7xxx series (such as 7075): high-strength aluminum alloy, more difficult to machine, but suitable for high-load applications.

(2) Tool type

Choosing the right tool is an important part of optimizing the best feed and cutting speed for milling aluminum.

Carbide tools: suitable for high-speed and high-feed processing methods, with strong wear resistance.

High-speed steel (HSS) tools: suitable for low-speed processing, low cost, but poor wear resistance.

Coated tools (such as TiN, TiAlN): reduce tool adhesion and increase service life.

(3) Tool geometry parameters

The geometric design of the tool directly affects the stability and efficiency of the cutting process:

Rake angle (usually 10°-20°): a larger rake angle can reduce cutting force and improve cutting efficiency.

Back angle (usually 10°-15°): prevent friction behind the tool and improve surface finish.

Helix angle (30°-45°): Improve chip removal capability and reduce built-up edge.

(4) Importance of machine tool rigidity

● High-rigidity machine tools help reduce vibration and improve machining accuracy.

● Insufficient machine tool rigidity may lead to increased vibration, affect surface quality, and accelerate tool wear.

● The accuracy of the machine tool guide and spindle system plays a decisive role in the stability of aluminum milling.

(5) Influence of spindle speed

● High-speed spindles (such as above 15,000 RPM) are suitable for aluminum processing and can improve processing efficiency.

● Under high speed conditions, cutting heat increases, which may affect the processing effect.

● It is necessary to combine suitable tools, feed speeds and effective cooling systems to prevent dimensional deviations and tool damage caused by heat accumulation.

2. Best feeds and speeds for milling aluminum: recommended cutting parameters

The cutting depth and cutting width usually depend on the specific process requirements. Generally, it is recommended:

Roughing: cutting depth 2-5mm, cutting width 50-70% tool diameter.

Finishing: cutting depth 0.5-1mm, cutting width 20-40% tool diameter.

3. Best feeds and speeds for milling aluminum: optimization strategies in practice

(1) Applicability of high speed & high feed

High speed combined with high feed can improve efficiency, but attention should be paid to tool durability and heat dissipation. Reasonable selection of tools and coolants can reduce tool wear.

(2) Solve the problem of built-up edge

Built-up edge affects surface finish. Optimization methods include:

● Use sharp blades to reduce cutting force.

● Use high helix angle tools to improve chip fluidity.

● Select appropriate cutting fluid to improve cooling effect.

(3) Use of coolant

Reasonable coolant can reduce tool overheating and built-up edge. Recommended use:

Emulsion (water-based coolant): Suitable for most aluminum processing.

Oil-based coolant: Suitable for high-precision processing and reduces tool adhesion.

(4) Application of High-Speed ​​Milling (HSM) in Aluminum Processing

HSM (High-Speed ​​Machining) can significantly improve aluminum milling efficiency. The main advantages include:

● Reduce cutting force and increase tool life.

● Improve surface quality and reduce the need for subsequent polishing.

● Adopt a processing strategy with a smaller cutting depth but a high feed rate to increase material removal rate.

4. Common problems and solutions in aluminum milling

Various problems may be encountered during aluminum milling. It is crucial to understand the root causes of these problems and take appropriate solutions.

(1) Rough cutting surface

1) Possible reasons:

● Feed speed is too high.

● Tool wear.

● Insufficient cutting fluid.

● Unstable tool installation or insufficient tool holder rigidity.

2) Solutions:

● Reduce feed speed and optimize cutting parameters.

● Replace tool or adjust tool angle.

● Use appropriate amount of cutting fluid.

● Ensure that the tool is firmly installed and improve machine rigidity.

(2) Tool wear is too fast

1) Possible reasons:

● Cutting speed is too high or too low.

● Aluminum chips adhere to the tool.

● The tool coating is not suitable for the type of aluminum being processed.

2) Solution:

● Use a suitable tool coating, such as TiAlN.

● Increase the cutting speed to reduce the adhesion between the tool and the material.

● Choose a more wear-resistant tool material, such as a nano-coated tool.

(3) Poor chip removal

1) Possible reasons:

● The tool helix angle is not suitable.

● Insufficient coolant supply.

● The chips are too long and easily entangled with the tool.

2) Solution:

● Use a high helix angle tool.

● Increase the flow of cutting fluid to improve chip removal capacity.

● Use high-pressure gas or coolant to flush the chips to prevent entanglement.

5. Conclusion

The best feeds and speeds for milling aluminum are the core factors that determine the processing quality and production efficiency. Reasonable selection of tool type, optimization of cutting parameters, correct use of coolant, and combination of efficient milling technology can effectively improve the stability and accuracy of aluminum processing.

In the actual production process, the machine tool performance, tool life and material properties should be comprehensively considered, and the feed speed and cutting speed should be flexibly adjusted to achieve the best processing effect.