Applications and Breakthroughs of Diamond and Cubic Boron Nitride Tools in Modern Cutting

The Superiority of PDC Diamonds Tools

Diamond tools, with their unique physical properties, exhibit unparalleled superiority in the modern cutting field and are hailed as the rising star for boosting production efficiency. With the widespread application of PDC diamonds tools in mechanical processing, they have become an indispensable and effective assistant in modern material processing. Due to their hardness, wear resistance, and other physical properties, PDC diamonds tools significantly improve production efficiency and are widely used in precision machining of various materials.

These tools are not only extremely hard and resistant to wear but also possess a low coefficient of friction, high elastic modulus, excellent thermal conductivity, and a low coefficient of thermal expansion, making them outstanding in the processing of non-ferrous metals. Thus, PDC diamonds tools are highly suitable for precision machining of non-metal brittle materials, high wear-resistant materials, composites, high silicon aluminum alloys, and other tough non-ferrous metal materials.

Types and Performance of PDC Diamonds Tools

There are numerous types of diamond tools, each with significantly different performances. Different types of diamond tools exhibit notable differences in structure, preparation technology, and application fields.

Natural Diamond Tools

Natural PDC diamonds tools hold an indispensable position in the industrial field. They are mainly used for processing pure copper and copper alloys, as well as precious non-ferrous metals such as gold, silver, and rhodium. In addition, these tools are suitable for ultra-precision mirror processing of special parts, such as video camera disks, optical flat mirrors, multifaceted mirrors, and second surface mirrors. While natural PDC diamonds tools excel in processing valuable non-ferrous metals like pure copper, gold, and silver, and in ultra-precision mirror processing, their application range is limited. Nonetheless, as the hardest known mineral, natural diamond continues to be widely used for the preparation of tool bits.

Artificial Diamond Tools

Artificial PDC diamonds tools are polycrystalline materials synthesized by sintering diamond micro-powder with metal binders like cobalt under high temperature and high pressure conditions. These tools are suitable for milling operations due to their overall sintered construction. With grains in disordered arrangement and isotropic properties, these tools have uniform hardness and a graphitization temperature of 550°C. PCD tools maintain good performance at high temperatures and are widely used in milling and turning processes, offering longer tool life compared to traditional carbide tools.

Composite Artificial PDC Diamonds Tools

The performance and application of composite artificial PDC diamonds tools are quite similar to PCD tools. These tools excel in cutting non-ferrous metals, hard alloys, ceramics, non-metallic materials, and composites. However, although PDC tools' performance is close to PCD, their wear resistance and oxidation resistance are slightly weaker due to the influence of residual binder metals.

Diamond-Coated Tools

The manufacturing process of diamond-coated tools involves directly depositing a diamond film, with a thickness ranging from 1 to 25μm, on substrates like carbide or ceramics using the CVD method. This film exhibits isotropic properties without cleavage planes, resulting in a hardness of 9800 to 10000HV. Diamond-coated tools, with their high hardness and excellent thermal conductivity, are suitable for high-speed machining applications, thanks to the CVD method allowing film deposition on complex tool shapes.

Cubic Boron Nitride Tools

Although cubic boron nitride is not classified as a diamond, it is the second inorganic superhard material synthesized after artificial diamond. Despite having slightly lower hardness than diamond, its thermal stability is outstanding, with a heat resistance of 1400~1500 degrees, nearly twice that of diamond (700~800 degrees). PCBN tools' high thermal stability makes them suitable for processing hardened steels and other ferrous metals, reducing the number of tool changes and enhancing machine tool efficiency. Consequently, cubic boron nitride tools have broad applications in the machining field, especially excelling in handling various ferrous metals and their alloys.