With the extensive application of large-scale mining machinery in the construction of harsh working conditions such as coal mining, tunnel shielding, trench excavation, highway facilities and waterway dredging, picks have received extensive attention as key tools for cutting rock layers. The cemented carbide picks produced by the production process have problems such as poor wear resistance and easy shedding of the tooth head, resulting in frequent replacement of picks during construction. Therefore, the development of high-performance picks has become a research topic.
       Because of its excellent mechanical properties such as high wear resistance and high hardness, diamond has a broad application prospect as a high-performance pick material. According to cutting experiments, the pick of polycrystalline diamond composite disc (PDC) is better than the commonly used hard alloy pick The tooth life is 10-20 times longer, and the durability of digging in hard rock and abrasive rock is 100 times that of cemented carbide matrix.

Types and characteristics of diamond pick:
       1. Plating type

       The application of a composite electroplating process to the diamond wear-resistant layer on the surface of the tool is an effective way to improve the wear resistance of the tool. Applications. Because it avoids the shortcomings of oxidation or graphitization of diamond tools during high-temperature sintering, it can effectively achieve the combination of high wear resistance of diamond coatings and high toughness of the substrate, so it has also become an important way to improve pick performance. The diamond tools prepared by electroplating generally have the problem of low binding force between the coated carcass metal and the diamond particles. As a result, when the diamond particles are subjected to force, they are prone to loose and fall off, resulting in a shortened service life.

       2. Thermally stable composite sheet type

       Thermally stable polycrystalline diamond refers to polycrystalline diamond that is fired with micron-level single crystal diamond and can maintain the original physical and mechanical properties at a high temperature of 1200 degrees Celsius. It does not require cemented carbide as a substrate and its bonding Instead of using cobalt, the agent uses a low-melting silicon alloy or directly sinters at high temperature and high pressure without any binder.

       3. Strengthen the spur type

       The structure of the transition layer changes gradually from the surface to the inside elastic gradient and thermal expansion gradient. Therefore, the residual stress inside the spur decreases, the impact toughness increases, and the composite layer shedding phenomenon decreases. Comparison experiments with cemented carbide drills in tight sandstone at hydropower sites show that the life of diamond-reinforced cylindrical shank bit is 20 times longer than that of cemented carbide, and the efficiency is increased by 25%.

      4. Pregnancy type

       Diamond impregnated pick is a kind of high-performance pick which is sintered by hot pressing process, which adopts the method of powder metallurgy directly mixing the steel body and tooth head. The tooth head uses diamond powder as the main wear-resistant mixture, and its practical performance has been greatly improved compared with the carbide tip.

    5. Thermally stable type

       Thermally stable polycrystalline diamond is a polycrystalline diamond that is sintered using only micron-level single crystal diamond and can maintain the original physical and mechanical properties at high temperatures (1200 degrees Celsius). He does not need cemented carbide as a backing.
       Diameter protection method of diamond pick:
       According to research, many picks are easy to break and wear during use. In order to increase their wear resistance, China has developed a high wear resistance composite pick with a simple and compact structure that can improve the wear resistance of the tooth shank and tooth head , Only need to electroplating a diamond layer with a thickness of 0.6mm on the surface, diamond electroplating is carried out at room temperature, will not cause thermal damage to the diamond compound pick head and pick handle, maintaining the original performance of the diamond layer, and The wear resistance of this part is greatly improved, and the radial stability of this part during use is strengthened, so that the diamond composite pick can be consumed normally. The wear ratio of this pick is close to 100,000, which is a cemented carbide Thousands of times, the service life is 10-20 times longer than that of hard alloy, and the life of the pick is greatly improved.