Modern industry pursues efficient and stable parts processing to meet customers' dual needs for fast delivery and stable quality. In this context, aluminum, as a lightweight, strong, durable and corrosion-resistant alloy, has become an ideal material for widespread application. This has also led to the rapid development of a new milling aluminum technology - High-Speed Machining (HSM).
Compared with traditional milling methods, high-speed machining stands out for its extremely high cutting speed. Operators can take full advantage of this advantage by increasing the cutting feed. Therefore, in the processing of aluminum, the use of HSM strategy can bring many unexpected benefits compared to traditional milling. The following are the benefits of choosing aluminum HSM strategy instead of traditional milling.
1 Higher efficiency
By increasing the cutting speed to three times that of traditional aluminum milling, we can increase the feed rate to twice (especially for softer aluminum alloys). It is worth noting that the machining feed rate is a key factor in measuring the productivity of the entire milling process. Despite this, high-speed machining can still compete with traditional milling in terms of efficiency. Aluminum's high machinability allows spindle speeds to easily exceed 18,000 rpm or even higher, achieving amazing material removal rates.
Such material removal rates make aluminum machining services using HSM strategies very attractive in the automotive and aerospace industries. In the automotive manufacturing field, prototypes require a lot of material removal, so reducing milling settings is particularly important. In the aerospace field, many long and large parts have deep recesses and thin-walled structures (these parts are often machined into a set of intersecting ribs to reduce weight), and 80% of aircraft and rockets are made of aluminum alloys. Therefore, the application of HSM strategies in these fields is particularly profitable.
2 Cutting temperature
The relationship between cutting temperature and cutting speed shows an interesting change pattern. At first, as the cutting speed increases, the temperature also increases accordingly. However, when the cutting speed reaches a certain higher level, the temperature begins to drop sharply until it drops to a level that no longer has a significant impact on the machining process. At this point, even if the cutting speed is further increased, the temperature reduction becomes negligible. This temperature turning point is a significant feature of HSM technology.
Taking aluminum as an example, when the cutting speed is 300-500 m/min, the temperature of the cutting zone may be as high as 600-800 degrees Celsius. However, once the cutting speed is increased to 1200 m/min, the temperature will drop rapidly to less than 200 degrees Celsius; and when the cutting speed reaches 1800 m/min, the temperature is as low as only 150 degrees Celsius. From this speed, the effect of increasing the cutting speed on reducing the temperature is no longer obvious.
It is worth noting that in the low temperature range of 150-200 degrees Celsius, the material properties of the cutting zone remain unchanged, the metal particles will not increase due to high temperature, and the cooling demand is greatly reduced. This is undoubtedly a huge advantage.
3 Longer tool life
This may sound counterintuitive, because intuitively faster cutting speeds should lead to greater tool wear. However, when we compare the amount of material cut per unit time by aluminum cutting tools in HSM (high speed machining) and conventional milling, rather than simply the tool life in minutes, the difference becomes obvious, and HSM shows a clear advantage in aluminum processing. So what leads to longer tool life?
The first reason is the reduction in cutting temperature, which allows the strength of the tool material to be maintained. Secondly, in the HSM process, because the tool rotates very fast, even if the feed rate is increased, thinner chips can be cut, thus reducing the width of the chip.
In addition, a common problem when machining aluminum is that the aluminum is too soft and tends to adhere to the cutting edge of the tool during machining. This not only reduces the sharpness of the tool, but also increases the cutting force, which shortens the life of the tool. But in HSM, this situation rarely happens because the aluminum will quickly fall off the tool.
4 High-speed aluminum alloy processing
It is generally believed that an increase in feed rate is often accompanied by a decrease in the surface finish of aluminum, because the tool cutting edge has to move a longer distance, which requires more force and wider chips when cutting aluminum, thus affecting the smoothness of the surface.
However, in HSM (high-speed machining), the situation is different. Despite the high feed rates in HSM, the chips are actually cut thinner due to the extremely high rotation speed of the tool, and the chip width is greatly reduced compared to traditional milling. At the same time, due to the relatively low cutting forces, vibration during the process is also reduced. These two factors work together to enable HSM to maintain a good surface finish on aluminum while maintaining a high feed rate.
5 Constant tool engagement angle
In the process of milling part cavities with end mills, a core challenge is to create the groove angle. Specifically, when the end mill needs to rotate 90 degrees to form a groove, the amount of material it needs to cut will instantly double because it needs to cut from both sides of the groove at the same time. This change will cause a local surge in cutting forces, which will have an adverse effect on the life of the tool and the machining accuracy of the part.
However, HSM (High Speed Machining) aluminum milling technology provides us with a variety of preset tool path generation strategies, including a constant tool engagement angle strategy. This strategy ensures that the tool can gradually and steadily approach the target angle while machining the surrounding material along a circular trajectory. In this way, the cutting force can be kept constant, the machining accuracy can be guaranteed, and the life of the tool will be extended accordingly.
6 Use of coolant
Some HSM (high-speed machining) strategies for aluminum processing do not require coolant in actual operation. When the processing temperature only reaches 200 degrees, the material and the tool require almost no additional cooling. Of course, some customers explicitly require the use of coolant on the drawings in order to improve the quality of parts, but even so, the amount of coolant required is much lower than traditional processing methods. Some aluminum high-speed milling processes use the so-called "minimum lubrication" technology, that is, the amount of coolant applied is just enough to form a thin film on the contact surface to reduce friction and provide the necessary cooling effect.
In summary, high-speed aluminum milling is undoubtedly an innovative and efficient manufacturing method suitable for the production of customized parts, prototypes, small batch aluminum alloy kits and other products. By adopting high-speed machining technology, you can not only enjoy more favorable prices, but also significantly shorten the order completion time.(来源：UG学习堂小胥收徒)
