Parameter setting skills for CNC turning of copper alloy materials

When CNC turning copper alloy materials, parameter Settings need to comprehensively consider aspects such as the tool, cutting parameters, geometric parameters, and cooling and lubrication. The following are specific tips:

Tool selection

Material: It is recommended to use ultra-fine particle cemented carbide tools, especially suitable for tools with a diameter of less than 10 millimeters, to enhance wear resistance and cutting accuracy. For instance, for brass C27000, the use of ultra-fine-grained cemented carbide tools can effectively enhance tool life and processing quality.

Coating: It is recommended to use titanium nitride (TiN) coating or titanium aluminum nitride (TiAlN) coating. Titanium nitride coating can effectively reduce the friction between the tool and the material, and is suitable for medium to high-speed cutting. The nitrogen-aluminum-titanium coating shows better oxidation resistance in high-temperature cutting and is suitable for high-speed machining.

Geometric parameters:

Rake Angle: Generally set at 10° - 15°. For instance, for low-lead brass C33000, setting the rake Angle at 15° can ensure low cutting force and high precision.

Relief Angle: It is usually set at 5° - 10°, and can be adjusted specifically according to the tool diameter and processing requirements. For example, for medium lead brass C34000, setting the relief Angle at 8° helps to reduce cutting force and tool wear.

Cutting edge Angle: The cutting edge Angle of the tool is set within the range of 70° to 95°. For softer copper that is easily coated, a cutting edge Angle of approximately 90° is required to reduce the stress on the tool, increase tool life and cutting speed.

Cutting parameter setting

Cutting speed

For a tool with a diameter of 8 millimeters, the recommended cutting speed is 120 meters per minute. The 12-millimeter diameter tool is recommended to have a cutting speed of 150 meters per minute. It is suitable for materials such as brass C26000 and can ensure processing efficiency and surface quality.

For a tool with a diameter of 6 millimeters, the recommended cutting speed is 100 meters per minute. For a 10-millimeter diameter tool, it is recommended that the cutting speed be 130 meters per minute. For materials such as brass C27000, this can balance the cutting efficiency and tool life.

When rough turning, take v = 100m/min; when finish turning, take v = 300m/min. When selecting, the rigidity of the machine tool, workpiece, fixture, and tool process system should also be considered. If the rigidity is good, a larger value can be taken; if the rigidity is poor, it can be appropriately reduced.

Feed rate:

For an 8-millimeter tool, the recommended feed rate is 0.12 millimeters per revolution. 12mm tool, recommended feed rate of 0.18mm per turn, suitable for brass C26000, can improve processing efficiency while ensuring surface finish.

For a 6-millimeter tool, the recommended feed rate is 0.10 millimeters per revolution. For a 10-millimeter tool, the recommended feed rate is 0.15 millimeters per revolution. For brass C27000, it can ensure surface quality while achieving efficient processing.

Cutting depth:

The initial cutting depth is recommended to be 1.0 mm. For smaller diameter tools (such as 8 mm), it can be appropriately reduced to 0.8 mm to minimize tool load and heat accumulation. This is suitable for materials like brass C26000.

The initial cutting depth is recommended to be 0.8 millimeters. For larger diameter tools (such as 10 millimeters), it can be appropriately increased to 1.2 millimeters. For brass C27000, this can improve processing efficiency, but the cutting force and heat accumulation need to be controlled.

Other parameter Settings

Main deflection Angle: 75° can be taken during rough turning and 90° during finish turning to facilitate cutting.

The radius of the tool tip should be reduced as much as possible to prevent the application of softer metal and to lower the surface roughness. Compared with traditional tip radius tools, wiper inserts are the preferred tool because they can improve the surface finish without changing the feed rate.

Cooling and Lubrication

Coolant: Water-based or oil-based coolant can be used to help dissipate heat and extend tool life. For some precision processing scenarios, dry cutting can also be considered, but it is necessary to pay attention to controlling the cutting temperature.

Micro Lubrication (MQL) : By mixing compressed air with an extremely small amount of cutting oil and vaporizing it, it is sprayed into the processing area to effectively lubricate the machined parts between the tool and the workpiece. This can effectively reduce the friction between the tool and the workpiece, as well as between the tool and the chip, prevent adhesion, extend the tool life, and improve the quality of the machined surface.