1 Introduction
Hard and brittle materials refer to materials that have high hardness and high brittleness, and are generally non-conductive or semi-conductive, such as various kinds of stone, glass, silicon crystals, quartz crystals, hard alloys, ceramics, and the like. With the development of science and technology and modern industry, the application fields of hard and brittle materials are expanding, and the processing technology of hard and brittle materials is also constantly developing. In various hard and brittle materials processing methods, cutting processing plays an important role. For example, in the processing of building decorative plates and precision parts of rock materials, sawing is the first process of machining, and the cost of sawing accounts for more than 50% of the total processing cost. Currently, various diamond cutting tools are used for cutting and processing hard and brittle materials such as stone. As diamond is the hardest material known in nature, its excellent properties determine its broad prospects for development in the field of cutting and processing of hard and brittle materials such as stone.
The processing methods for sawing hard and brittle materials by using diamond tools mainly include: circular saw blade cutting, diamond band saw cutting, diamond frame saw cutting, and diamond bead saw cutting. Although each method has its own different characteristics and application range, its cutting mechanism and diamond wear mechanism are roughly the same. As rock cutting is the most important use of diamond cutting tools, it is of great significance to deeply study the mechanism of stone sawing and the wear mechanism of diamond cutting tools for the rational manufacture and correct use of diamond cutting tools. For a long time, experts and scholars at home and abroad have conducted extensive experiments and research on the processing mechanism of diamond tool sawing granite, the wear mechanism of diamond tools, and the sawing power in the sawing process, and have achieved remarkable results. The research and development of processing and diamond tools have played an active theoretical guiding role.
2 Diamond cutting stone sawing mechanism
Diamond abrasives are usually made into cutting tools by sintering or plating. The cutting process of diamond tools is similar to that of grinding. However, due to the influence of materials, the processing mechanism of hard and brittle materials such as rocks and ceramics is different from the metal processing mechanism, and the processing process is more complicated. Since the diamond cutting tool was first applied to stone cutting, there are many researches on the mechanism of diamond cutting stone. Domestic and foreign scholars have conducted long-term research on the processing mechanism of diamond tools sawing granites. From the early application of rock fracture theory under the intrusion of the indenter, single-grain diamond scratch surface morphology observation method has gradually developed to comprehensive application of polarizing microscope and scanning electron microscope. Observe the morphology of rock processing surface and the generation and propagation of cracks, and use acoustic emission signals to evaluate the cutting status of rocks. However, due to the complex cutting and cutting processes of hard and brittle materials such as rocks, the study of its cutting mechanism has not yet formed a unified understanding.
Similar to the grinding process, people first studied the mechanism of action between single diamond particles and stone during cutting. Early experimental studies have shown that: When single-grained diamonds cut granites under different conditions, the main failure modes of the rock are brittle collapse; at the same time, according to different mineral compositions, there are still plastic deformations in the rock.
It is well-known that in modern metal cutting, tooling costs account for only a fraction of the entire manufacturing cost, but the overall processing cost occupies a crucial part. Therefore, in addition to controlling the cost of the tool itself, the tool can be used more rationally, the production efficiency can be fully improved, the processing time can be shortened, and the cost can be ultimately reduced by reducing the processing cost.
From our machine tool sales process, we often discuss with customers, why do you want to buy Walter company cnc tool grinder? Usually we get the answer: the end-user's requirements for cutting tools are getting higher and higher. In the past, tools that were simply made and machined by hand have been unable to meet the end user's processing requirements in terms of accuracy and shape.
Therefore, in our experience of selling more than 140 machine tools in China, we have summarized the following general requirements for our customers:
The runout of the tool requires control. With the deep use of high-speed milling, the circumference of the tool, the end surface, and the runout at the arc are all expected to be controlled within 0.005mm. Because we all know that when the tool is actually used, its runout will change due to the accuracy of the clamping system and the runout of the machine's own spindle, which will usually increase. Therefore, the jitter can be easily controlled within the required range on the CNC tool grinder. The jerk is guaranteed, and the adjustment of the geometric parameters of the tool can be rationally used in any situation. For example, when processing non-ferrous metals in the metallurgical industry, it is possible to use a large rake angle to make the cutting more brisk, and to use the auxiliary rake angle when machining hard metals such as cast iron. As the stability of the tool is improved, the cutting speed and feed rate can also be improved. The user no longer has to reduce the rotational speed and feed rate simply because of the vibration during processing. The production efficiency can also be greatly improved.
Tool geometry requirements. With the continuous improvement of modern machining requirements, more and more people use composite tools to replace the previous multi-step processing. In order to improve the processing efficiency, the processing requirements for complex parts require multiple machining processes in one setup. And gradually dilute the traditional milling, drilling, hinge, expansion and other different cutting process boundaries, is currently the most limited way to improve processing efficiency. For this reason, people demand that the tool can complete multi-process processing of the product, reduce the number of tool changes, save the time of tool change, and greatly save the amount of tool inventory, which is followed by the reduction of management costs.
Therefore, with the development of the tool market, Walter Machine Tool Co., Ltd. has successively introduced molding tool packages that are more adaptable to market requirements over the years: from composite milling cutters, composite drill bits to toroidal (spherical) milling cutters, and dovetail slot milling. The versatility and flexibility of the software, such as knife and ladder type slot milling cutters until Christmas tree milling cutters, are increasingly recognized and accepted by the market. The processed knives are also widely used in aircraft manufacturing, metallurgical industry, mold processing and steam turbines. industry.
Strong technical support and follow-up machine tool technology development. Walter, as an internationally renowned company, has always been regarded as the company's goals and objectives. Our subsidiary in Jiangsu Wuxi is responsible for the after-sales service and technical support for machine tools across the country. At the same time, we will launch our self-love China Customer Demonstration Center in Taicang, Jiangsu in May 2006 to sub-regional sales and service organizations. The customer got our help the first time.
We joined the Schleifring Group in September 2004. We have a strong backing from this group company with absolute authority in the field of international grinding. We are more confident in the development and optimization of machine tools. In line with the needs of customers and the market, we will share in research, development, manufacturing, materials, sales, and services, the enormous potential generated by our successful experience. This is exactly the best prerequisite for Walter Machine Tool to continue to expand its achievements and develop new products.
The development of cutting technology must be closely integrated with machine tools and tools, and foreign advanced developed countries are taking such a development path. We have introduced world-class machine tools, and we will help our customers gradually move from the simple "sales knife" to the end user to improve the "complete processing program" mode of thinking. From the perspective of end-user tools, it will also fully tap the potential of cutting technology, and use its own professional strength to improve the company's market competitiveness.