(1) Composition and classification of diamond bits

1. Composition of diamond bit

Diamond drill is a tool for diamond drilling broken rock, it is composed of three parts, namely:

1 - Diamond; 2 - carcass; 3 - Drill body

2. Classification of diamond bits

According to the different parts of the diamond coated in the matrix, there are impregnated diamond bits and surface diamond bits. The bit which inserts the diamond inside the matrix is called impregnated diamond bit; A diamond coated bit exposed to the surface of the body is called a diamond coated bit.

Diamond bits can also be divided into coring diamond bits and rope coring diamond bits according to their different uses. According to the different production materials, it is divided into polycrystalline diamond (PCD) bit and diamond composite sheet (PDC) bit. According to the different processing technology and method, it is divided into hot pressing and electroplating drill bit.

(2) Structural parameters of diamond drill bit

The structural parameters of diamond bit include: bit body, diamond content, diamond particle size, matrix hardness, water mouth, bit lip shape and so on.

1. Drill body

The production requirements of the diamond bit body are as follows:

Generally made of medium carbon steel. The bit body of the two-pipe drill is longer, generally 115mm, the wall is thin, and the upper end is connected with the internal thread and the reamer.

The bit body of the single tube drill is short, generally 75mm, the wall is thicker, and the upper end is connected with the external thread and the reamer.

The amount of diamond embedded in a drill bit is called the diamond content and is measured in carat ct.

2. Diamond content

The content is determined based on the bit structure, diameter and the nature of the rock being drilled. The diameter of drill bit is large, the area of extracting rock is large, and the amount of diamond is large. On the contrary, less. With the same diameter and structure drill bit, drilling strong abrasive formation, the diamond content should be larger, to reduce the burden of single diamond, maintain the bit longer working time. Drilling small abrasive rock, the diamond content should be smaller, in order to facilitate the cutting edge. Generally, the diamond content of the same diameter impregnated diamond bit is slightly more than that of the same diameter table impregnated bit.

3. Diamond granularity

It is divided into particle grade and powder grade.

The particle size diameter of granular diamond is greater than 1mm, and its particle size is expressed in particle /ct. The particle size of powder grade diamond is less than 1mm, and the particle size is expressed as "mesh". The "mesh" is the mesh number, which is the number of mesh holes in each square inch of the screen.

The diamond size of the surface insert bit is expressed by particle /ct. The diamond size of impregnated bit is expressed as "mesh".

4. Diamond drill the first body

The drill head body is a ring of alloy encrusted with diamond at the bottom of the bit. It is mainly composed of two parts: skeleton material and bonded metal.

The quality of a diamond bit depends largely on the composition of the drill head and its performance. The body was prepared by powder metallurgy and electroplating.

The function of the head body of the diamond insert is to firmly encrusted with diamond and reliably welded with the rigid body. The matrix of impregnated bit not only has the function of the first matrix, but also ensures that the diamond has the role of self-sharpening during drilling.

The hardness grade of the diamond drill head is expressed by HRC plus hardness value respectively. Such as :HRC45,HRC40,HRC35,HRC30, etc.

5. Diamond bit orifice

The water orifice of the drill is composed of water tanks at the bottom, inside and outside.

The role of the bit nozzle: the same as the role of the cemented carbide bit; Dredge the washing liquid; Cooling drill bit; Discharge rock powder; Ensure safe drilling and construction.

6. Diamond bit lip shape

The lip shape of the diamond bit is determined by the properties of the rock. The purpose is to increase the drilling rate, improve the stability of the drill tool and extend the service life of the drill bit.

The common profile shapes of the lip are curved edge, semicircle, flat bottom, step, cone and sawtooth.