The selection and matching principles of diamond burr are crucial to ensure drilling efficiency and drill bit life.
The selection of diamond burr should first consider the hardness of the rock formation to be drilled. For soft to medium-hard rock formations (grades 1-6 in the diamond core drilling rock drillability classification table), it is generally advisable to use natural surface-set drill bits, composite drill bits or polycrystalline drill bits. These drill bit types have good cutting performance and wear resistance in soft to medium-hard rock formations. For hard to hard and dense rock formations (grades 7-12 in the classification table), it is advisable to use impregnated drill bits, such as concentric circles with pointed ring grooves or staggered pointed ring grooves, or fine-grained surface-set diamond burr. These drill bits can better meet the drilling needs of hard rock formations and improve drilling efficiency.
The abrasiveness and crushing degree of the rock formation are also important factors in selecting diamond burr. A diamond burr with a high wear resistance should be used for highly abrasive rock formations, a medium wear resistance should be used for medium abrasive rock formations, and a low wear resistance should be used for weakly abrasive rock formations. For complex rock formations, the stronger the abrasiveness and the harder the rock, the better the diamond grade and the finer the particle size should be. In addition, in highly abrasive and broken rock formations, diamond burrs with higher diamond concentrations should be selected to ensure the wear resistance and service life of the drill bit.
The structure of the diamond burr should also be selected according to the characteristics of the rock formation. In broken, soft and hard interlayers, cracks or highly abrasive rock formations, such as coal formations, it is advisable to use sharp-toothed broad-spectrum drill bits or reinforced electroplated impregnated drill bits with good wear resistance. These drill bit structures can better meet the drilling needs of complex rock formations and reduce the risk of drill bit wear and breakage.
When selecting a diamond burr, it is also necessary to consider the reasonable matching of the drill bit and the drill tool. The outer diameter of the reamer should be 0.3mm-0.5mm larger than the outer diameter of the drill bit (not more than 0.3mm for hard rock formations) to ensure the reaming effect and reduce wear. At the same time, the inner diameter of the diamond burr and the free inner diameter of the retaining ring must be reasonably matched to prevent core blockage. In addition, the diameter difference between the drill bit and the drill tool should be small so that they can be used in order according to the size of the inner and outer diameters of the drill bit to improve drilling efficiency.
The selection and matching of diamond burr also needs to consider the influence of drilling process parameters. During the drilling process, parameters such as drilling pressure, rotation speed and pump volume should be reasonably controlled to meet the drilling needs of different rock formations. For example, when drilling hard to hard rock formations, the rotation speed is the main factor in improving the drilling speed of the impregnated drill bit; when drilling hard rock formations, the main focus should be on increasing the drilling pressure. Reasonable drilling process parameters can give full play to the performance of diamond burr and improve drilling efficiency.
The quality and brand of diamond burr are also factors that cannot be ignored when choosing. High-quality brands and manufacturers usually have stricter quality control systems and technical strengths, and can provide more reliable and durable diamond burrs. Therefore, when choosing diamond burr, you should pay attention to brand selection and give priority to manufacturers with good reputation and credibility.
Finally, when choosing a diamond burr, you also need to consider economy and practicality. Diamond burrs of different types and specifications have different prices and service lives. Therefore, when choosing, you need to weigh the drilling needs and budget and choose the diamond burr with the best cost performance. At the same time, you also need to consider the practicality and operability of the drill bit to ensure the smooth progress of the drilling operation.
The selection and matching principles of diamond burr involve many aspects, including rock hardness, abrasiveness and crushing degree, drill bit structure, matching of drill bit and drilling tools, drilling process parameters, drill bit quality and brand selection, and economy and practicality. Only by comprehensively considering these factors can you choose the most suitable diamond burr to ensure drilling efficiency and drill bit service life.
