Aluminum CNC Machining Service

Some Benefits and Drawbacks of Aluminum for CNC Machining

Benefits

Lightweight: Aluminum is a lightweight metal, making it an excellent choice for parts that require a low weight-to-strength ratio. This is particularly important in industries such as aerospace and automotive, where weight reduction can significantly improve fuel efficiency and performance.

Corrosion-resistant: Aluminum is highly resistant to corrosion, making it an ideal choice for outdoor and marine applications.

Easy to machine: Aluminum is relatively soft and easy to machine, allowing for high-speed machining and excellent surface finishes.

Good thermal conductivity: Aluminum has excellent thermal conductivity, making it an ideal choice for heat sinks and other heat dissipation applications.

Recyclable: Aluminum is fully recyclable, making it an environmentally friendly choice.

Drawbacks

Low strength: Aluminum has lower strength compared to other metals like steel or titanium, which can limit its use in applications where high strength is required.

High thermal expansion: Aluminum has a high coefficient of thermal expansion, which can lead to dimensional instability in parts with tight tolerances.

Softness: While aluminum’s softness makes it easy to machine, it also makes it more susceptible to scratching and wear.

Limited temperature range: Aluminum’s low melting point and thermal conductivity can limit its use in high-temperature applications.

More expensive: Aluminum can be more expensive compared to other metals like steel or copper, which can impact the overall cost of parts.

Steel Versus Aluminum CNC Machining

MACHINABILITY — Being less dense than steel means aluminum can be machined three or even four times faster. Aluminum also cools more quickly than steel; this reduces how long it takes to machine a part (cycle time) and the amount of coolant required.

COST — Mild steels and carbon steels are generally cheaper than aluminum alloy equivalents. Whereas stainless steel tends to be more expensive. However, the price of the metal varies depending on global demand and the cost of raw materials, energy, and shipping.

When looking at cost, it’s also important to consider a material’s durability. A decision that might save money in the short term could cost more in the long term.

WEIGHT — Aluminum is two to three times lighter than steel. Almost every company is looking to achieve the same or better product performance while incorporating lighter materials. This “lightweight” trend has seen manufacturers substituting many parts previously machined from steel for aluminum.

STRENGTH — Steel may be heavier than aluminum but this makes it a much more durable material. Steel is incredibly strong and is unlikely to warp, bend or otherwise deform under force, heat, or weight. Additionally, the surface of aluminum is more prone to scratches and dents compared to steel.

CORROSION RESISTANCE — Aluminum and stainless steel are both highly resistant to rust and corrosion. However, stainless steel is a more costly option. Manufacturers or end-users will need to paint, treat or coat every other type of steel to protect it, especially if they intend to expose the finished part to the elements. These coatings mean additional weight and cost, and they also need to be regularly reapplied at further expense.

What are the most common aluminum CNC machining processes?

1. CNC metal lathes, or CNC metal turning centers, firmly hold and rotate a workpiece while a tool head holds a cutting tool or drill against it. These machines allow for very precise removal of material and manufacturers use them in a broad range of industries.

Typical lathe operations include drilling, shaping, slot-making, tapping, threading, and tapering. CNC metal lathes are swiftly replacing older, more manual production models due to their ease of setting up, operation, repeatability and accuracy.

2.CNC milling machines are the most common and versatile way of machining aluminum parts. The machine uses rotating cutting tools to efficiently and precisely carve material from a stationary block of material.

Traditional milling machines transformed into “machining centers” in the 1960s thanks to the arrival of computer numerical control (CNC) systems, automatic tool changers, and tool carousels. These machines are available in 2- to 12-axis configurations, although 3 to 5-axis are the most widely used.

3. CNC plasma cutters heat compressed air to a very high temperature to create a “plasma arc” capable of melting metal up to six inches thick. The sheet material is held flat against a cutting table and a computer controls the path of the torch head. The compressed air blows away the hot molten metal, thereby cutting through the material. Plasma cutters are fast, precise, relatively easy to use, and affordable, and manufacturers use them in many industries.

4. CNC water cutters use extremely high-pressure jets of water forced through a narrow nozzle to cut through the material. Water on its own is enough to cut through soft materials like wood or rubber. To cut through hard materials such as metal or stone, operators usually mix an abrasive substance with water.

5. CNC laser machines either melt, burn, or vaporize material away to create a cut edge. Similar to a plasma cutter, sheet material is held flat against a cutting table and a computer controls the path of the high-power laser beam.

Laser cutters use less energy than plasma cutters and are more precise, particularly when cutting thin sheets. However, only the most powerful and expensive laser cutters are capable of cutting through thick or dense materials.

Conclusion

CNC aluminum machining is the ideal CNC machining material. Manufacturers can machine it three or even four times faster than other common machined materials such as steel and titanium. Aluminum has the advantages of low light-to-weight ratio, corrosion resistance, and ease of machining and recycling, but it has low strength, high coefficient of thermal expansion, high softness, limited temperature range, and is more expensive.