In the field of modern machining, the selection of tools plays a vital role in machining efficiency and quality. Cubic boron nitride tools and carbide tools are two common cutting tools, in the processing of cast iron, cubic boron nitride tools show a number of unique advantages.

First, higher hardness and wear resistance

Cubic boron nitride (CBN) is a super-hard material, its hardness is second only to diamond. In the processing of cast iron, CBN tools can withstand higher cutting forces and temperatures, to maintain good cutting performance. In contrast, cemented carbide has a lower hardness and is prone to wear during machining, requiring frequent tool changes, which reduces machining efficiency.

Cast iron materials usually contain high hardness particles, such as silicon, manganese, etc. These particles cause serious wear to the tool during the cutting process. the high hardness and wear resistance of CBN tools enable them to effectively resist these abrasions and extend tool life. According to statistics, when machining cast iron, the life of CBN tools can be several times or even tens of times that of carbide tools.

Second, better thermal stability

Processing cast iron will produce a lot of heat, the tool's thermal stability for processing quality and tool life is critical. CBN tools have good thermal stability, can maintain its hardness and strength at high temperatures. When cutting cast iron at high speeds, CBN tools can withstand cutting temperatures up to 1200°C or more, whereas carbide tools begin to soften and lose their cutting ability at temperatures above 800°C. The good thermal stability of CBN tools makes them ideal for machining cast iron at high temperatures.

Good thermal stability allows CBN tools to maintain stable cutting performance when machining cast iron, reducing tool wear and chipping phenomenon. At the same time, it can also improve machining efficiency, allowing the use of higher cutting speeds and feeds.

Higher machining accuracy

CBN tools have sharp cutting edges and good cutting performance, and can process higher precision parts. When machining cast iron, CBN tools can obtain better surface quality and dimensional accuracy, reducing machining errors.

When machining cast iron, cemented carbide tools are prone to wear and deformation due to the limitations of their hardness and wear resistance, thus affecting machining accuracy. In addition, the cutting edge of cemented carbide tools is not sharp enough, which is easy to leave scratches and burrs on the machining surface, requiring subsequent processing.

Fourth, a wider range of applicability

CBN tools are not only suitable for processing a variety of cast iron materials, can also be used for processing other difficult to machine materials, such as hardened steel, high temperature alloys. In contrast, the scope of application of cemented carbide tools is relatively narrow, for some of the higher hardness of the material processing effect is not good.

In the processing of cast iron, different cast iron materials have different hardness and strength, CBN tools can be adjusted according to different processing requirements, choose the appropriate tool material and cutting parameters to obtain the best processing results.

In summary, cubic boron nitride tools have higher hardness and wear resistance, better thermal stability, higher machining accuracy and wider applicability than cemented carbide tools in machining cast iron. In modern machining, choosing the right tool is crucial for improving machining efficiency and quality. For machining cast iron and other difficult-to-machine materials, cubic boron nitride tool is undoubtedly a more ideal choice.

The following are some practical examples of CBN tools for machining cast iron:

Case 1: Automobile engine block machining

Automobile engine block is generally made of gray cast iron. In traditional machining, when using carbide tools, due to the complex structure of the cylinder block, the machining allowance is not uniform, the tool wear is fast, and frequent tool changes are required, resulting in low machining efficiency. With the use of CBN tools, the wear resistance and thermal stability of the tools are greatly improved. In high-speed cutting conditions, CBN tools can maintain stable cutting performance, not only greatly improve the machining efficiency, but also after machining the cylinder surface quality is higher, better dimensional accuracy. For example, an automobile manufacturer in the processing of engine block, the use of CBN tools, machining efficiency increased by more than 30%, tool life is about 5 times that of carbide tools.

Case 2: Brake drum machining

Brake drums are usually made of ductile cast iron, which requires high machining accuracy and surface quality. When machining with carbide tools, problems such as fast tool wear and rough machined surfaces are likely to occur. CBN tools can effectively solve these problems. In an automotive parts manufacturing enterprises, the use of CBN tools for machining brake drums, cutting speed doubled, while the tool life has been extended by more than 3 times. The machined brake drums have low surface roughness and high dimensional accuracy, meeting strict quality requirements.

Case 3: Machine bed machining

The machine bed is generally made of gray cast iron, which is large and heavy, and requires high machining accuracy and stability. In traditional machining, carbide tools are difficult to meet the requirements of high-precision machining, and tool wear is serious, affecting machining efficiency and cost. A machine tool manufacturer uses CBN tools to machine the bed of the machine tool, through optimizing the cutting parameters, to achieve high efficiency and high precision machining. After machining the bed surface quality is good, flatness and straightness error control in a very small range, improve the overall performance and stability of the machine tool. At the same time, tool life has been significantly extended, reducing production costs.