At present, the CNC tool materials widely used mainly include diamond tools, cubic boron nitride tools, ceramic tools, coating tools, carbide tools and high speed steel tools. The tool materials used for NC machining must be selected according to the workpiece and processing properties. The selection of tool materials should be reasonably matched with the objects to obtain the longest tool life and maximum cutting productivity.
The mechanical properties of the cutting tool material and the machined object are matched.
The matching problem of mechanical properties between cutting tool and machining object mainly refers to the matching of mechanical properties parameters such as strength, toughness and hardness of cutting tool and workpiece material. Cutting tool materials with different mechanical properties are suitable for different workpiece materials.
The hardness order of tool material is: diamond tool > cubic boron nitride tool > ceramic tool > carbide > high speed steel.
The order of bending strength of cutting tool materials is: high speed steel > carbide > ceramic cutting tool > diamond and cubic boron nitride cutting tool.
The toughness of the cutter material size order: high speed steel > carbide > cubic boron nitride, diamond and ceramic tools.
High hardness of the workpiece material, must be processed with a higher hardness of the tool, the hardness of the tool material must be higher than the hardness of the workpiece material, generally required in more than 60HRC. The higher the hardness of the tool material, the better its wear resistance. For example, when the amount of cobalt in cemented carbide increases, its strength and toughness increase, its hardness decreases, and it is suitable for rough machining; When the cobalt content decreases, its hardness and wear resistance increase, and it is suitable for finishing.
Cutting tools with excellent high temperature mechanical properties are especially suitable for high speed cutting. The excellent high temperature performance of ceramic tools enables them to cut at a high speed, the allowable cutting speed is 2 ~ 10 times higher than that of cemented carbide.