Cutting Application of PCD Cutting Tools

Due to the limitations of CBN itself (anisotropy) and its manufacturing technology, it is still difficult to produce large-grain CBN single crystals directly used for cutting tools. The size of CBN particle is an important factor affecting PCD toughness. The larger the particle size is, the weaker its resistance to destruction is, and the sharpness of the cutting edge of the tool is worse. The organization of PCD tool is composed of unordered arrangement of various micro-grains, uniform hardness and no directionality, and has consistent wear resistance and impact resistance, overcoming the shortcomings of CBN anisotropy. Because of the comprehensive properties of PCD tool such as red hardness, thermal stability, wear resistance and anti-adhesion, PCD tool has been widely used in the cutting of quenched steel and cast iron.

1. Cutting Application of PCD Cutter in Hardened Steel

For example, a cold stamping core cavity component with an irregular curve shape, the surface-related dimensions and roughness must be strictly processed according to the drawing. The material of the workpiece is molud steel, and the material is Cr12MoV, with a hardness of 58±2HRC. The processing process is as follows: blanking (φ186mm×66mm)-rough lathe-milling (processing hole)-heat treatment-flat grinding-fine lathe-clamping (removal of burrs, engraving).

The difficulty of processing this part is that the hardness of the workpiece is high, and the curved surface can only be processed by turning. The machining surface must be smooth. Based on the outer circle, the curve angle and related dimensions must be ensured to be consistent, and there must be no over-cutting or tool marks.

In the selection of cutting tools, we should choose a symmetrical angle tool holder, CBN blade (the angle is 35°), and ensure that the turning is not over-cutting. The selection of PCD blade is very important. The PCD blade must have stable cutting performance. During the cutting process, the thermal conductivity performance of the blade should be good. The heat at the tip of the blade can be quickly transferred out during processing, and there should be no residual layer or debris on the machining surface.

2. Cutting Application of PCD Cutter in Wear-resistant Cast Iron Parts

In the production and manufacturing process, manufacturing enterprises are most concerned about how to improve cutting efficiency. Mechanical manufacturing process and mechanical design engineers have been working hard to think. We summarize the most important considerations from six aspects: tools, improved process solutions, improved fixture, optimized cutting parameters, reducing auxiliary time or selecting high-power machine tools. The last five items are easy to understand. Here, the tools we are talking about are composite multi-functional tools, which are specially designed and manufactured to complete two or more machining processes for a specific part, and can achieve the quality requirements of single-functional tool machining parts.

According to the conventional processing method, at least three processes, including drilling, boring holes, and chamfering, are required to complete the stepped hole machining. During the machining process, tool change and boring tool diameter adjustment are required, and the chamfering tool programming method needs to be optimized. It is time-consuming and laborious, and there are too many processes, which can easily cause mistakes during the machining process. However, using composite multi-functional tools can complete rough and finish machining, chamfering process at one time. The PCD cutting tools used in the machining process are specially designed with strong reliability, effectively optimizing the production process, and reducing the machining cost.

3.Cutting Application of PCD Cutter in Non-ferrous Metals and Non-metallic Materials

Diamond has excellent properties such as high hardness, good wear resistance, high strength, good thermal conductivity, and anti-adhesion. It is considered to be the most ideal material for cutting precision tools. Diamond is divided into natural diamond, synthetic diamond, and polycrystalline diamond according to material.

At present, the composite sheets used by many PCD cutting tools in China mainly come from foreign countries, and there is still a big gap compared with foreign countries, mainly showing unstable cutting performance, short service life, and low cost-effectiveness.

However, PCD cutting tools are gradually recognized and put into use by large-scale well-known enterprises, and are used to process non-ferrous metals (such as Cu, Al, Ag and their alloys) and non-metallic materials (ceramics, wood, and reinforced plastics). At the same time, some enterprises also use natural diamonds and synthetic diamond tools to process parts. Here we mainly talk about how to choose PCD cutting tools correctly for cutting applications of electrical materials contacts.