Before you begin to machine aluminum, you should know a few important facts about the material. Learn about its non-ferrous nature, malleability, and machining characteristics. Next, learn how to choose the proper cutting tool. The right tool should have the right helix angle, carbide grade, and number of flutes.
Material’s malleability
The degree to which a material can be shaped or deformed depends on its malleability. This property is related to its atoms, which are arranged in a way that makes them more pliable under compression. A good example is copper, which can be easily stretched into wires or sheets. Most malleable metals are also ductile. These properties are not mutually exclusive, as lead and tin are both ductile and pliable when cold. However, as they approach their melting points, they become increasingly brittle and less malleable.
The amount of plasticity a metal has depends on how it has been shaped. The finer the grain, the better the plasticity. A uniform structure also increases malleability.
Its nonferrous nature
Aluminum is a nonferrous metal, and this makes it particularly versatile for machine applications. The metal has excellent strength-to-weight ratios, some resistance to corrosion, and is relatively easy to machine. Other nonferrous metals include brass and copper alloys, which are commonly used because of their decorative properties. Copper is also used in turbine engines due to its electrical conductivity, but it is only useful in hot sections.
Aluminum is available in different alloys, each with its own unique properties. Some grades have higher levels of aluminum than others, so it is important to understand the type of alloy you are using before machining it. Pure aluminum is soft, corrosion resistant, and has a high electrical conductivity. It is often used in foils and as a conductor for electricity and heat. Aluminum alloys are made by mixing the metal with other elements to increase their strength.
Its machinability
Aluminum is a versatile metal that is lightweight and easy to machinate. It is more machinable than ferrous metals such as steel and stainless steel, and this property makes it suitable for a wide range of applications. In addition, aluminum is cheaper to machine than other metals and is a lighter metal than steel and stainless steel. All these qualities make aluminum a better choice for machining.
There are three grades of aluminum. The highest strength aluminum rod is 7075, with a machinability of 2017 to 2024. This metal is not recommended for screw machine use, as it is unable to meet straightness tolerances. It also has average corrosion resistance and is often used for aircraft parts.
Its machining characteristics
The machining characteristics of aluminum are influenced by the alloy. Different alloys have different machinability characteristics, which are important to consider when designing a metal part. For instance, aluminum in the form of Mg17Al12 has a high cutting speed and produces discontinuous chips. These features contribute to the machining characteristics of aluminum and promote higher cutting forces.
Aluminum’s machining characteristics can also be affected by the tools used. The tooling geometry needs to be suitable for the materials and the material being machined. The proper tooling geometry helps you get a good surface finish and reduce the buildup of metal. The rake angle should be between 0 and 40 degrees. A negative rake angle should not be used in any case.
Tool design
Optimal tool design for aluminum machining begins with understanding the material being cut. Not all aluminum grades are equal, and not all types of tools will cut the same. For example, a general-purpose cutter for steel won’t cut aluminum because of the material’s gumminess. Aluminum is also different from steel due to the friction and heat involved in cutting it. If you’re considering purchasing a new machine for aluminum work, it’s important to choose the proper tool design for the job.
For many years, two-flute end mills have been the standard choice for aluminum machining, but three-flute tools have shown superior results in many finishing operations and are also effective roughers. However, the type of tool you choose depends on several factors, including the type of operation, rigidity, and the desired material removal rate.