What are the requirements for material hardness in CNC machining

1、 The adaptability of different processing techniques to material hardness

Cutting Processing

For cutting machining, it is easier to process when the material hardness is moderate. If the material is too hard, tool wear will accelerate, cutting force will increase, which may lead to a decrease in machining accuracy, deterioration of surface quality, and even damage to the tool and machine tool.

For example, when processing alloy steel with higher hardness, it is necessary to choose tools with higher hardness and reduce cutting speed and feed rate to reduce tool wear. For materials such as aluminum alloys with lower hardness, cutting is relatively easy, and higher cutting speeds and feed rates can be used to improve processing efficiency.

Milling processing

The requirements for material hardness in milling processing are similar to those in cutting processing. Harder materials will increase the wear of milling cutters and also increase the load on the machine tool.

For example, when milling die steel with high hardness, it is necessary to choose high-quality milling cutters and adopt appropriate cooling methods to ensure machining quality and tool life. For materials such as plastics with lower hardness, milling can be faster and more efficient.

Drilling processing

When drilling, excessive hardness of the material may cause the drill bit to break. Therefore, when selecting drill bits and determining machining parameters, it is necessary to consider the hardness of the material.

For example, when processing stainless steel with high hardness, it is necessary to choose high-strength drill bits and reduce drilling speed and feed rate. For materials such as wood with lower hardness, drilling is relatively easy.

2、 Suitable hardness range for different material types

Metallic materials

Steel: Generally speaking, steel with a hardness between HRC20 and HRC60 is more suitable for CNC machining. Steel with lower hardness is easy to process, but may not have sufficient strength; Steel with higher hardness requires higher processing techniques and better cutting tools.

Aluminum alloy: The hardness of aluminum alloy is relatively low, generally between HB50-HB150. Due to its lightweight and good thermal conductivity, it has been widely used in fields such as aerospace and automotive manufacturing. For CNC machining of aluminum alloys, it is necessary to choose appropriate cutting tools and machining parameters to avoid sticking and surface quality issues.

Copper alloy: The hardness of copper alloy is relatively low, generally between HB50-HB200. Copper alloys have good conductivity and thermal conductivity, and are commonly used in electrical, electronic, and other fields. When processing copper alloys, attention should be paid to tool wear and surface quality issues.

Non metallic materials

Plastic: The hardness of plastic varies greatly, generally between Shore A hardness A20-D80. Plastics with lower hardness are easy to process, but may not have sufficient strength; Plastics with higher hardness require higher processing techniques and better cutting tools.

Composite materials: The hardness of composite materials depends on their constituent materials and manufacturing processes. Generally speaking, composite materials have higher hardness and greater processing difficulty. When processing composite materials, it is necessary to choose appropriate cutting tools and processing parameters to avoid problems such as delamination and cracking.

3、 The influence of hardness on machining accuracy and surface quality

Processing accuracy

The hardness of the material will affect the machining accuracy. If the material is too hard, it is prone to vibration and deformation during the processing, thereby reducing the machining accuracy.

For example, when machining high-precision parts, it is necessary to choose materials with moderate hardness and use appropriate machining processes and tools to ensure machining accuracy.

surface quality

The hardness of materials can also affect surface quality. If the material is hard, scratches and burrs are prone to occur during the processing, thereby reducing the surface quality.

For example, when processing parts with high surface quality requirements, it is necessary to choose materials with moderate hardness and use appropriate processing techniques and cutting tools to ensure surface quality.