- Why use CNC milling for aluminum parts
- Characteristics of the aluminum alloy CNC milling process
- Solutions for machining aluminum alloys
- Aluminum vs. steel for CNC milling
- Summing up
Aluminum alloy parts are widely used in various industries due to their unique properties, such as low density, high strength, and good corrosion resistance. Aluminum and aluminum alloy processing can be classified as rolling, extrusion, drawing, forging, spinning, forming, and deep processing. This article will discuss the characteristics of CNC milling of aluminum alloy parts.
Why use CNC milling for aluminum parts
CNC aluminum parts are usually cheaper than other metals, such as steel, because they can be machined quickly. They also do not require additional polishing. Small amounts of zinc, magnesium, copper, and other materials are added to improve strength, as pure aluminum is usually softer. When exposed to the atmosphere, it forms a thin protective layer that makes it resistant to corrosion and reduces the chance of surface rust. It is chemical resistant, easy to work with, and strong compared to its weight.
Aluminum is one of the most commonly processed materials because of its excellent mechanical properties. Its properties include flexibility, tolerability, durability, and corrosion resistance. In recent years, CNC precision machining of aluminum parts has become commonplace, especially in military, medical, aerospace, and industrial engineering. Advanced technology and CNC machines are used for CNC aluminum parts because of the high precision they require.
One of the advantages of milling aluminum parts is that it is a versatile material that can be used in different fields. It has excellent features, such as lightness and durability. Aluminum also needs to be glorious. It can be used in various fields, such as aircraft manufacturing, power generation, and automobile manufacturing. In the automotive manufacturing industry, it manufactures reflectors commonly used in automotive lights.
Characteristics of the aluminum alloy CNC milling process
1、Low hardness of the aluminum alloy
Compared with titanium alloy and its hardened steel, the hardness of aluminum alloy is low; of course, the hardness of heat-treated or die-cast aluminum alloy is also high. The HRC hardness of ordinary aluminum plates is generally below HRC40 degrees. Therefore, when machining aluminum alloy, the tool load is small. And because of the better thermal conductivity of aluminum alloy, the cutting temperature of milling aluminum alloy is relatively low, which can improve its milling speed.
2、Aluminum alloy with low plasticity
The plasticity of aluminum alloy is low, and the melting point is also low. When machining aluminum alloy, its sticky tool problem is serious, the chip removal performance is poor, and the surface roughness is relatively high. Machining aluminum alloy is mainly about the sticky knife and bad roughness effect. As long as the two major problems of sticky tool and surface quality are solved, the problems of aluminum alloy machining will be solved.
3. High-speed machining
Aluminum alloys have a low melting point and excellent thermal conductivity, making them easier to machine at high cutting speed. High-speed machining uses high spindle speeds and feed rates to reduce machining time and increase productivity. High-speed machining also improves surface finish, accuracy, and longer tool life.
4. Low-cutting forces
Aluminum alloys have a low density, which means they have low cutting forces compared to other materials. This property reduces wear on cutting tools and allows smaller tools and higher cutting speeds, resulting in better surface finishes and increased productivity.
5. Tendency to adhere
Aluminum alloys adhere to cutting tools due to their softness and elasticity. This can lead to a buildup of material on the cutting edge, which affects the surface finish and causes tool wear. To minimize adhesion, it is important to use cutting tools with a low friction coefficient and appropriate cutting fluid to flush away chips.
6. Chip formation
Aluminum alloys produce long, continuous chips during milling, which can lead to chip buildup and affect surface finish. Appropriate chip removal methods must be used to prevent chip buildups, such as high-pressure coolant or air jets to remove chips from the cutting area.
7. Surface finish
Aluminum alloys have excellent surface finish characteristics, which means that the surface roughness of the finished part is smooth and free of defects. This is due to the material’s low cutting forces and excellent thermal conductivity. However, proper cutting tools and parameters must be used to achieve the desired surface finish.
8. Machinability
The machinability of aluminum alloys varies depending on the particular alloy being machined. Some alloys are easier to machine than others due to their composition and microstructure. For example, 6061 aluminum alloy is considered good machinability, while 7075 aluminum alloy is more difficult to machine due to its high strength and hardness. The machinability of the alloy must be considered when selecting the appropriate cutting tools and parameters.
Solutions for machining aluminum alloys
Due to the relatively low strength and hardness of the aluminum alloy, the plasticity is small. It is very difficult to machine aluminum alloy, but the melting point of aluminum alloy is low. The plasticity increases after the temperature rises, so the friction at the cutting interface is great under high temperatures and pressure. It is easy to stick to the knife, especially for the annealed aluminum alloy, and it is not easy to get low surface roughness. To obtain a smooth surface for the workpiece, rough and fine cutting is used as far as possible. Various qualified workpiece blanks always have some oxidation layer, resulting in considerable wear on the tool. It might be better to use polished sharp milling cutters for the final cutting process.
One of the ways is to add aluminum-silicon alloy, aluminum-silicon alloy according to the silicon content to choose the appropriate tool material; silicon content below 12% can be adopted ISO K10-K20 chip tumor once formed, it will replace the cutting edge, and the bottom of the chip tumor is relatively stable. At the same time, the top is very unstable and easy to rupture; part of the rupture with the chip discharge, and the other part of the machining surface, so that the machining surface. The unevenness of the part of the chip tumor that protrudes beyond the cutting edge will also directly make the machined surface roughness, and the friction between the chip tumor and the machined surface will also increase the surface roughness. Therefore, it is recommended to use special milling cutters for aluminum alloy, which are produced to solve this problem.
Aluminum vs. steel for CNC milling
Aluminum is about one-third the weight of steel. It can also conduct heat and electricity easily, which makes it an ideal material for making steel tanks. Aluminum reflects heat and light and is ductile and non-magnetic. Some companies specialize in producing custom CNC-milled aluminum parts. This is primarily because they are both economical and portable. Compared to other materials such as brass and steel, aluminum CNC-milled parts are often cheaper because they can be machined quickly. It also does not require a new polish.
Summing up
Thanks for reading the article; the above is a detailed introduction to the characteristics of CNC milling aluminum alloy machining, part of the content from the Internet, for reference only. If you want to know more about the specific matters related to aluminum alloy milling processing characteristics, welcome to contact ANPLLO, we will serve you with all our hearts.