Plunge milling, often referred to as Z-axis milling, is an effective machining method for high metal removal rates. It is particularly advantageous for machining curved surfaces, difficult materials, grooving, and situations where tools have large overhangs. Compared to conventional face milling, plunge milling is much more efficient in these cases. When there is a substantial amount of metal to be removed quickly, plunge milling can reduce machining time by more than half.
▉ Advantages
In addition, plunge milling has the following advantages:
① It can reduce the deformation of the workpiece;
② It reduces the radial cutting force on the milling machine, allowing a spindle with a worn shaft system to be used for plunge milling without compromising the quality of workpiece processing.;
③ The tool overhang length is large, which is very beneficial for milling grooves or surfaces of the workpiece;
④ Plunge milling is an effective technique for machining high-temperature alloy materials, such as Inconel. It is particularly suitable for rough machining mold cavities and is recommended for the efficient production of aviation parts. One notable application of plunge milling is in the machining of turbine blades, which can be performed on three-axis or four-axis milling machines. However, this often requires the use of specialized machine tools.
▉ Working Principle
When milling turbine blades, the workpiece can be machined from the top down to the root. By simply translating in the X-Y plane, it’s possible to create extremely complex surface geometries. In plunge milling, the cutting edge of the milling cutter is formed by overlapping the profiles of each blade. The plunge milling depth can reach up to 250 mm without causing vibration or distortion.
The cutting movement of the tool can be directed either downward or upward, though downward cutting is generally more common. When milling an inclined surface, the plunge milling cutter moves in a compound manner along both the Z-axis and X-axis. Additionally, for various processes such as milling grooves, profiles, inclined surfaces, and concave cavities, other types of milling cutters like spherical or face milling cutters may also be employed.
▉ Scope of application
Plunge milling cutters are specialized tools primarily used for roughing or semi-finishing operations. They are designed to cut into the concave areas of a workpiece or along its edges and can also be utilized to mill complex geometric shapes, including root profiles. To maintain a consistent cutting temperature, all shank plunge milling cutters are equipped with internal cooling features.
The design of the cutter body and blades allows plunge milling cutters to engage the workpiece at an optimal angle. Typically, the cutting edge angle of these tools is either 87° or 90°, with a feed rate range of 0.08 to 0.25 mm per tooth. The number of blades attached to each plunge milling cutter varies based on the cutter’s diameter. For instance, a cutter with a diameter of 20 mm is typically fitted with two blades, while a 125 mm cutter can have up to eight blades.
When determining if plunge milling is suitable for processing particular CNC components, it is important to consider the specific requirements of the task and the characteristics of the milling machine being used. If the task demands a high metal removal rate, plunge milling can significantly reduce processing time.
Plunge milling is particularly suitable for tasks that require a tool with a large axial length, such as machining deep cavities or grooves. This method effectively reduces radial cutting forces, leading to greater machining stability compared to side milling. Additionally, plunge milling can be advantageous when machining parts on a workpiece that are hard to reach with conventional milling techniques. The plunge milling cutter’s ability to cut upward allows for the machining of complex geometric shapes.
From the perspective of machine tool capability, plunge milling is a good option when the processing machine’s power is limited. This is because plunge milling requires less power than spiral milling, making it feasible to use older or underpowered machine tools to achieve higher machining efficiency. For instance, deep slots can be processed using a level 40 machine tool; however, these machines may struggle with long-edge spiral milling cutters due to the large radial cutting forces involved, which can lead to cutter vibration.
Since plunge milling generates lower radial cutting forces, it is well-suited for older machines with worn spindle bearings. This method is primarily used for rough machining or semi-finishing, as the minimal axial deviation caused by wear in the machine’s shaft system will not significantly affect the quality of machining. As a new CNC machining approach, plunge milling also introduces new requirements for CNC machining software.
If you want to know more or have an inquiry, please feel free to contact info@anebon.com.
Anebon depends on sturdy technical force and continually creates sophisticated technologies to meet the demand for CNC lathe machining parts, 5-axis CNC milling, and aluminum die casting parts. The good cooperation could improve both of us into better development!
Post time: Jan-13-2025