Why do aluminum alloy turning parameters need special treatment?

The reason why aluminum alloy turning cannot simply copy the parameter template of steel processing is due to its three major physical characteristics:

Good thermal conductivity and low melting point: The thermal conductivity of aluminum is about 3-4 times that of steel, and cutting heat quickly enters the tool and chips, but the melting point of aluminum itself is only 660 ℃. Once the temperature in the cutting area is too high, aluminum chips will "cold weld" to the front cutting surface of the tool, forming chip lumps. This hard block repeatedly contacts the surface of the workpiece during the cutting process, pulling out irregular marks on the surface, making the surface of the part look like it has been scraped.

High plasticity and viscosity: Aluminum has a high elongation rate, and during cutting, the chips are in a continuous strip shape. If the chip is not discharged smoothly, it will entangle the workpiece and tool. At the same time, aluminum has affinity for many tool coatings and is prone to sticking to the tool.

High coefficient of linear expansion: The thermal expansion coefficient of aluminum is about 23.6 μ m/℃, which is more than twice that of steel. During processing, temperature rise can cause dimensional drift, which is particularly fatal during precision machining - a temperature difference of 5 ℃ between day and night can cause a difference of 0.1mm in 400mm long parts.

The optimization goal of aluminum alloy turning is not to blindly pursue "fast cutting", but to "cut quickly and steadily while suppressing chip accumulation". This determines that our parameter selection logic is completely different from steel processing.