*Applications of Polycrystalline Diamond (PCD) Materials in Oil and Gas Industry DOI: http://dx.doi.org/10.5772/intechopen.107355*

levels, the performance of synthetic or man-made diamonds is more controllable and consistent. Therefore, synthetic diamonds (grit or bulk) are the first choice for most industrial applications. Another reason is that they cost relatively little. One of the most successful tools for using synthetic diamond is the PDC cutter for oil and gas drill bits, which significantly improves drilling economy by increasing drilling speed (ROP) and tool life, as shown in **Figure 4**. Although PCDs have been successfully used in oil and gas drilling tools, they still suffer from catastrophic failures from time to time due to their inherent low fracture toughness compared to other cutting materials such as cemented carbide. In the course of oil and gas exploration, many different rock formations may be encountered. Some will be coarser than others, while others will consist of a mixture of hard and softer phases, which will have a significant impact on the tool when drilling. These shocks can cause micro-cracks, fragmentation, or spalling, which can seriously impair the drilling schedule. It is also thermally unstable at high temperatures, which is likely to occur during drilling, especially in hard formations. When the PDC cutter heats up due to strong rock/cutter friction during the drilling process, the expansion of the metal Co far exceeds that of the diamond grain, resulting in extensive thermal stress and further cracking.
