Diamond is composed of carbon atoms and is a crystalline material formed under high temperature and pressure. It is rated as 10 on the Mohs hardness scale. Diamond has not only high hardness and strength, but also high thermal conductivity. It can absorb heat easily and dissipate it quickly. Small-diameter diamond drilling is currently one of the main methods for rock drilling in water conservancy projects. However, abnormal wear such as burning and malfunction during drilling often occurs, which affects the normal drilling process. In order to improve the drilling efficiency and reduce the cost of diamond drilling, it is necessary to have a better understanding of the performance of diamond drill bits and master the correct usage methods to reduce abnormal wear of the drill bit and increase its lifespan. Below we will briefly introduce the characteristics of coreless diamond pressurized roller drill bit.
The strength and thermal stability of coreless diamond pressurized roller drill bits
Diamonds have high hardness, strength, and thermal conductivity, but also disadvantages such as brittleness and poor thermal stability. They are easily broken by impact and can easily oxidize and graphitize under high temperature conditions. Temperature has a significant impact on the strength of diamonds, which decreases as the temperature rises. When heated to 300°C in the air, diamond drill bits begin to oxidize, and their weight starts to decrease at 800°C, causing a change in crystal color. At 900°C, diamond quality changes significantly, becoming porous and brittle. At 1000°C, diamonds burn cleanly, forming carbon dioxide afterwards.
The adaptability of coreless diamond pressurized roller drill bits
Coreless diamond pressurized roller drill bits have strong adaptability to different geological formations. By selecting the appropriate drill bit according to the different geological formations, diamond drill bits can achieve long service life and high efficiency. When the rock is at level 8-9, it is more suitable to use matrix hardness HRC34-42, diamond grain size of 60-100 mesh embedment or electroplated diamond drill bits. However, when encountering harder granite veins or quartz veins, this type of drill bit is not suitable and softer matrix hardness and finer diamond grain size should be used.
