5-Axis Machining Case of Impeller Blade: Challenges and Tool Selection

Five-axis machining is an advanced Computer Numerical Control technology with high precision and dedication to machining complex surfaces. The impeller is a part that is usually produced using 5-axis machining, what challenges are there, and how to solve them?

Common Challenges in 5-Axis Machining

With the addition of the machine tool rotary axis, milling, drilling, boring, and another machining of all planes except the installation base plane can be easily completed; Since 5-axis CNC machining equipment has two more degrees of freedom of rotation than traditional three-axis equipment, it can quickly realize free machining in any direction, which is convenient to change and adjust the cutter axis direction and improve the machining conditions. However, due to the two additional degrees of freedom, path planning is difficult, and the possibility of tool and workpiece interference is greatly increased. Complex machining needs more stable and flexible tool combinations to complete.

(1) Tool interference. Since five-axis NC machining equipment has two more degrees of freedom of rotation than traditional three-axis equipment, which makes path planning difficult, and the possibility of tool and workpiece interference greatly increases, how to avoid interference has become the first problem to be solved by tools.

(2) Tool rigidity. In order to avoid interference, too large and too long tools are often used, but this brings the problem of insufficient tool rigidity. The tool vibration during processing is too large, which affects the processing accuracy and the tool is very easy to be damaged.

(3) Tool stability and flexibility. The essence of five-axis machining is to provide high efficiency and high precision products, which requires that the tools have high stability and flexible combination. The cutting tool combination can be quickly changed according to different machining to improve machining efficiency and cutting quality.

Impeller Machining Case

Among the numerous machined workpieces, the difficulty in machining the impeller blade is prominent. The impeller is the core component of an aero-engine, steam turbine, and also an important part of mixers in the food industry. In an aero-engine, the turbine blade is in the position with the highest temperature, the most complex stress, and the worst environment, so it is called the first key part. Because of its complex curved surface structure and nearly harsh application environment, impeller blades become the most typical difficult-to-machine structural parts.

Impeller diameter: 600mm

Workpiece material: titanium alloy

Processing method: rough, semi-finish, finish

Processing equipment: machining center

Cooling conditions: emulsion

(1) Tool selection for rough machining of workpieces:

Firstly, the plane milling cutter handles and UFO flying saucer self-rotation series are selected for roughing the workpiece.

Tool handle: BT40-FMB27-60

UFO cutter head: DR12-066-A27-07

UFO Frisbee Blade: DR12-8B3

(2) Tool selection for runner roughing:

For the curved surface and gap of the runner, the following combination is selected for efficient processing.