Manufacturing Process of PCD Cutter and Cutting Process of Composite Sheet

What is the manufacturing technology of PCD cutters? As far as we know, the PCD cutter is a new type of superhard material that has been studied and used internationally since the 1970s. It is formed by sintering at a high temperature of 1400°C and a high pressure of 6GPa. Then let's take a look at the process of PCD cutter manufacturing technology.

Ⅰ. Manufacturing process of PCD cutters: The manufacturing process of PCD cutters mainly includes two stages

1. Manufacturing of PCD composite sheets

PCD composite sheet is made of natural or synthetic diamond powder and binder (which contains cobalt, nickel and other metals) sintered under high temperature (1000-2000℃) and high pressure (5-100,000 atmospheres) in a certain proportion.

During the sintering process, due to the addition of the binder, a bonding bridge MyCIMT with TiC, SiC, Fe, Co, Ni, etc. as the main components is formed between the diamond crystals, and the diamond crystals are embedded in the bonding bridge skeleton in the form of covalent bonds. Usually, the composite sheet is made into a disc with a fixed diameter and thickness, and the sintered composite sheet needs to be ground, polished and other corresponding physical and chemical treatments.

2. PCD blade processing

PCD cutter blade processing mainly includes steps such as composite sheet cutting, blade welding, and blade sharpening.

Ⅱ. PCD composite sheet cutting process

Due to the high hardness and wear resistance of PCD composite sheets, special processing techniques must be adopted. At present, the processing of PCD composite sheets mainly adopts several process methods such as wire electric discharge cutting, laser processing, ultrasonic processing, and high-pressure water jet.

1. Comparison of PCD composite sheet cutting process

(1) Process method - process characteristics: EDM - highly concentrated pulse discharge energy, strong discharge explosion force melts the metal of PCD material, part of the diamond is graphitized and oxidized, and part of the diamond falls off, with good manufacturability and high efficiency.

(2) Ultrasonic processing - low processing efficiency, large consumption of diamond powder, and large dust pollution.

(3) Laser processing - non-contact processing, high efficiency, small processing deformation and poor manufacturability.

The above processing method, EDM has better effect. The presence of bond bridges in PCD makes it possible to EDM the compact. Under the condition of working fluid, the working fluid near the electrode metal is used to form a discharge channel, and a discharge spark is generated locally. The instantaneous high temperature can melt and fall off the polycrystalline diamond, thereby forming the required triangular, rectangular or square cutter head blank.

The efficiency and surface quality of EDM PCD composite sheets are affected by factors such as cutting speed, PCD particle size, layer thickness and electrode quality. If it is low, it will produce the phenomenon of "arching wire" and reduce the cutting efficiency. Increasing the thickness of the PCD cutter blade also reduces the cutting speed.