PDC cutter is also called diamond composite sheet (PDC-Polycrystalline Diamond Compact). Because PDC cutter has excellent anti-abrasion and impact resistance, it is widely used in geological drilling and  oil. 

PDC cutter is a composite superhard material sintered by diamond micropowder and cemented carbide substrate under ultra-high pressure and high temperature conditions. It has both the high hardness, high wear resistance and thermal conductivity of diamond and the strength and impact toughness of cemented carbide. It is an excellent cutting tool and wear-resistant tool material. It is now widely used in many fields such as metal and non-metal cutting tools, wood processing tools, oil and gas drill bits, etc.

The strength of PDC cutter is mainly determined by the strength of polycrystalline diamond composite teeth. Different application scenarios have different performance requirements for polycrystalline diamond composite teeth. Different structural designs can be selected according to specific application requirements and working conditions to achieve the best use effect.

What are the shapes of PDC cutter:

Flat shape PDC cutter, Domed shape PDC cutter, Roof shape PDC cutter, Helmet shape PDC cutter

Advantages of flat PDC cutter: high strength, wear resistance, fast drilling speed, suitable for uncomplicated geological exploration at a depth of 2000-3000 meters.

Advantages of Domed shape PDC cutter: high impact resistance, slow drilling speed, suitable for medium to hard and complex, inhomogeneous rock formations.

In geological drilling, coal drilling and oil and gas drilling, PDC composite drill bits have become one of the most commonly used rock-breaking tools due to their excellent rock cutting speed and long service life.

What are the advantages of diamond composite (PDC) drill bits:

1. The force balance design makes the drill bit have good guidance, suitable for downhole motors for directional drilling, and has small radial vibration;

2. The reasonable arrangement of patented PDC composite pieces of different structures at different positions of the drill bit makes the drill bit have strong aggressiveness and abrasive resistance;

3. The strong aggressive design can make the drill bit achieve a higher mechanical drilling speed;

4. The drilling ability in the rock formation is 10-30 times that of ordinary alloy drill bits, which improves the operation efficiency;

At the same time, diamond composite (PDC) C) The drill bit also has its indispensable shortcomings. Conventional PDC drill bits have several shortcomings:

1. Due to the large difference in the linear expansion coefficients of polycrystalline diamond and cemented carbide, the thermodynamic properties of polycrystalline diamond and cemented carbide at the interface between the two are not well matched, and there is a large residual thermal stress, which can easily lead to the delamination of diamond and cemented carbide;

2. The surface of PDC is mostly flat. In order to reduce the phenomenon of chip adhesion and the number of quality inspections, it is generally polished into a mirror surface to improve the surface finish, but the cost is high and the anti-sticking effect is not obvious;

3. With the continuous wear of the working edge of the PDC drill bit, its surface forms a plane or arc surface, the contact area with the rock increases sharply, the pressure on the rock drops sharply, the rock breaking speed decreases, and the wear accelerates. Especially for deep wells and ultra-deep wells, frequent replacement of drill bits will increase the drilling cycle and drilling costs.

PDC composite sheets have stronger pressure resistance, excellent rock breaking ability, excellent grinding resistance and impact resistance. The latest synthesis technology makes it have a longer service life, stronger anti-attack and higher temperature resistance. It can effectively maintain its original characteristics in high temperature environment, which greatly improves the efficiency of customers' drilling.

PDC composite sheets are products developed to meet the needs of drilling in complex formations. They are mainly suitable for oil and gas drilling under harsh geological conditions. PDC uses high-quality diamond and cemented carbide as raw materials and adopts advanced synthesis technology. Its products combine the advantages of diamond and cemented carbide. It has extremely high wear resistance, good impact strength and thermal stability, which greatly improves the drilling speed when drilling hard rocks.

Performance characteristics of PCD composite sheets for tools

(1) Compared with single crystal diamond, PCD composite sheets as tool materials have the following advantages:

* The grains are disordered, isotropic, and have no cleavage planes. Therefore, it does not have large differences in strength, hardness and wear resistance on different surfaces like large single-piece diamonds, and is brittle due to the presence of cleavage planes.

* It has high strength, especially PDC material has high impact resistance due to the support of cemented carbide matrix. When it is hit hard, only small particles will be broken, instead of large pieces of iron like single diamond. Therefore, PCOD or PDC tool can be used not only for precision cutting and ordinary semi-precision machining, but also for rough machining and intermittent machining (such as milling), which greatly expands the application range of diamond tool materials.

* Large PDC diamond composite sheet tool blanks can be prepared to meet the needs of large processing tools such as milling cutters.

(It can be made into a specific shape to suit the needs of different processing. Due to the large-scale PDC tools and the improvement of processing technologies such as EDM and laser cutting technology, triangles, herringbone shapes and other special-shaped tools can also be processed and formed)

The performance and cutting characteristics of PCD composite sheets as cutting tools are as follows:

①PCD has a high hardness, second only to natural diamond, and its hardness and wear resistance are isotropic, that is, various physical properties remain consistent in all directions

②It has extremely high wear resistance, and its wear resistance is generally 60~80 times that of cemented carbide. (It has a lower friction coefficient. Therefore, when processing the same material with the same processing parameters, the use of PCD tools can significantly reduce the cutting force and reduce the cutting temperature. At the same time, due to the reduction of the friction coefficient, the surface finish of the workpiece is also greatly improved. ④It has a very high thermal conductivity, which is 1.5~7 times that of cemented carbide, which can greatly reduce the temperature of the cutting area and improve the durability of the tool.

⑤The linear expansion coefficient of diamond is very small, so the processing accuracy is good.

How to choose grinding wheel for PDC cutter?

Moresuperhard can provide vitrified and resin diamond grinding wheel for PDC cutter, 1A1 vitrified diamond cylindrical grinding wheel have good self-sharpening with pores and little damage to the spindle of the grinding machine, sharp and the grinding efficiency is high. When grinding, the cutter is not back-off and the size of PDC is a good consistency.

Resin bond cylindrical grinding wheel has good self-sharpness, and good surface finish, customer usually  use larger size resin grinding wheel. 1A1 wheels are used for cylindrical grinding in manufacturing and dressing PDC drill bits, and most resin diamond grinding wheel for PDC cutter with diameter size above 350mm.

---EDITOR: Doris Hu

---POST: Doris Hu