The Characteristics Of PCD Cutters And How To Use Them
In the past, high price has always been a major obstacle to the widespread acceptance of PCD (polycrystalline diamond) cutters by users, but now the situation has changed a lot. The industry estimates that in the past two to three years, the price of PCD cutters has dropped by 40–60. One of the reasons for the “diving” of PCD tool prices is that the supply of market exceeds demand. In the early 1990s, the development momentum of PCD cutters began to surpass that of traditional cemented carbide cutters, and in the following ten years, the market demand for PCD cutters continued to increase. However, as PCD cutter manufacturing technology matured, its sales growth momentum began to slow down. In addition, new competitors entering the PCD tool manufacturing industry have also shaken the original market price system. Another reason for the decline in the price of PCD cutters is the continuous reduction of cutter manufacturing costs, and the continuous improvement of tool manufacturing processes (such as EDM technology for rough machining of diamond blanks, cutting edge precision machining processes, etc.). In addition, compared with ten years ago, the quality of diamond grinding wheels for processing PCD cutters has been significantly improved, and the cost has been greatly reduced. my country’s demand for PCD cutters is increasing.
Features of PCD cutters
Using PCD cutters to process aluminum workpieces has the advantages of long tool life and high metal removal rate. The disadvantage is that the cutters are expensive and the processing costs are high. This point has reached a consensus in the machinery manufacturing industry. However, many changes have taken place in the development and application of PCD cutters in recent years. Today’s aluminum materials are different in performance. When processing various newly developed aluminum alloy materials (especially high silicon content composite materials), in order to achieve the optimization of productivity and processing quality, you must carefully choose PCD cutters Brand and geometric parameters to adapt to different processing requirements. Another change of PCD cutters is the continuous reduction of processing costs. Under the combined effect of market competition pressure and tool manufacturing process improvements, the price of PCD cutters has dropped by more than 50%. The above trend has led to the increasing application of PCD cutters in aluminum processing, and the applicability of the cutters is restricted by different processed materials.
Use correctly
When cutting aluminum alloy materials, the rough cutting speed of cemented carbide cutters is about 120m/min, while the cutting speed of PCD cutters can reach about 360m/min even when roughing high silicon aluminum alloys. Tool manufacturers recommend the use of fine-grained (or medium-grained) PCD grades to process silicon-free and low-silicon aluminum alloy materials. Use coarse-grain PCD grades to process high-silicon aluminum alloy materials. If the surface finish of the milled workpiece fails to meet the requirements, a wiper blade with a smaller grain size can be used to trim the surface of the workpiece to obtain a satisfactory surface finish.
The correct application of PCD cutters is a prerequisite for obtaining satisfactory processing results. Although the specific reasons for tool failure are different, it is usually caused by incorrect use of objects or methods. When ordering a PCD tool, the user should correctly grasp the scope of the cutter.
Generally speaking, in order to reduce the cutting force and prevent the build-up of edge, PCD cutters should use a positive cutting angle. However, when processing high silicon aluminum alloys (especially when PCD cutters are used instead of cemented carbide cutters for processing), the clearance angle of PCD cutters is better to be slightly smaller than the clearance angle used by the original cemented carbide cutters (such as 250). Improve the cutting performance of PCD cutter cutting edge on high silicon aluminum alloy. The positive rake angle of the PCD tool should not be too large, because the larger the rake angle of the tool, the lower the strength of the cutting edge. In other words, the smaller the relief angle of the PCD cutter, the higher the strength of the cutting edge. In order to increase the cutting edge strength as much as possible while ensuring that the tool has a positive cutting angle, a company in the United States welded a CNMX blade with a negative rake angle to the PCD tool tip and formed a positive cutting angle. In this way, the negative rake angle of the blade is both Provides a higher cutting edge strength without affecting the normal cutting of the tool. When preparing the cutting edge of PCD cutter, there is no need to do too much processing on the diamond tip. For PCD milling cutters, the cutting edge can be slightly sharpened. In addition, a certain axial inclination of the cutting edge will also help improve the PCD cutter cutting performance.
The successful application of PCD inserts not only depends on the reasonable selection of tool geometry and cutting parameters, but sometimes also requires PCD cutters suppliers to provide solutions to problems encountered in the use of cutters.