Diamond rope saw comprehensive analysis

1 Introduction

As a cutting tool for flexible superhard materials, diamond wire saw has been developed for more than 40 years since its inception. From the initial electroplating technology, it has developed into a manufacturing technology with sintering and brazing as the mainstream technology; The application of stone materials to the mining of blocks, the reinforcement of concrete or metal structural parts, which are widely used in granite mines, has resulted in a new era of manufacturing technology and a wider range of applications. At present, the comprehensive performance of domestic diamond wire saws is close to the international advanced level, and the cost is low. It can fully meet the needs of the domestic stone mining and sheet metal processing industries. There are even many companies that have begun to export a large number of wire saw products to Western countries such as Europe and the United States. With the rapid promotion of the use of diamond wire sawing machines and diamond wire saws cutting technology, China's stone block mining has entered the era of diamond wire saws, and diamond wire saw manufacturers have achieved unprecedented development. Domestic diamond wire saw manufacturing enterprises have promoted the rapid progress of domestic diamond wire saw technology through independent innovation, which has laid a solid foundation for the further promotion and application of diamond wire saws.

2. New process for making diamond wire saw

With the increase in the use of diamond wire saws and the continuous expansion of the application surface, the production technology of diamond wire saws is also continuously improving. In order to comply with the rapid development of domestic and foreign markets, and to catch up with the international advanced level, some domestic companies in recent years With the continuous introduction of new equipment and research and application of new technologies, while the scale of production continues to expand, product quality and production efficiency have also been greatly improved.
(1)Granulating and volumetric automatic cold pressing process
At present, domestic wire saw manufacturers generally use non-granulated powders for manual cold-pressing and beading production. The production efficiency is low, the product quality is easily affected by human factors, and the working environment has more dust and is not conducive to human health.
In view of the many disadvantages of using non-granulated powder for cold pressing, some domestic companies first applied the powder granulation technology and related equipment to the production practice. Powder granulation process is to add powder into the container by the high-speed rotation of the agitator and the cutting knife and spray the atomized solvent to make the powder form granules. The granulation powder of 10kg can be finished in 20 minutes. The granulation powder is dried and sieved. , Made of 30 to 80 mesh spherical particles, molding rate of 85% or more. The powder produced by this method has better fluidity. After the diamond is mixed with the granulated powder, the distribution of the diamond on the working lip is more uniform; the coated diamond surface is covered by the powder and avoided during the pressing process. Direct contact with the mold surface, reducing the loss of the mold.
With the powder granulation technology and diamond coating technology, some domestic companies introduced foreign automatic cold presses to produce beaded products. The equipment is based on the volumetric method (the amount of fixed powder) from the charge to the substrate and the carcass. Cold forming with a high degree of automation, saving manpower, which greatly increased production efficiency and reduce production costs.
(2)Hot isostatic pressing
Diamond bead sintering is an important link in the production of wire saws and directly affects the sawing performance of wire saws. Beads are cylindrical thin-walled structures, requiring high sintering density. The usual hot-press sintering methods are too thin for upper and lower pressure heads and poor pressure resistance, which directly limits the sintered density of beading, and has a large loss of head and cost. high. The traditional method of pre-cold pressing and non-pressure sintering, the bead sintered has lower density and seriously affects the performance of the wire saw. At present, the most effective sintering method is the use of hot isostatic pressing (HIP) technology. The application in beading production is to place the sintered beads in a glass sleeve (other companies do not put glass sleeves directly into hot isostatic pressing. In a sintering furnace), it is placed in a hot isostatic press, and inert gas Ar gas is used as a pressure transmission medium, and the temperature is raised to 800° C. to 900° C. for isostatic pressure treatment, and then the glass sleeve is removed by drum treatment or shot peening. . The beads produced by this technology have less porosity and high density, can increase the hardness, strength, abrasion resistance and working life of the beads, and can also improve the bonding strength between the matrix and the carcass; due to the large cavity, one-time With thousands of beads, it is good for mass production.

3 the new technology of diamond wire saw

(1) Brazing technology
The impregnated diamond tool is a special composite material made by mixing diamond particles and metal powder and sintering them. The diamond particles are generally distributed randomly in the carcass. As the carcass wears continuously during the working of the tool, the layers of diamond particles continuously expose and act as a micro-cutting edge to cut the cut material. Fall off, continuous work in the form of relay, cycled to consume. The distribution of sintered beaded diamonds in the carcass is random, the intervals between the abrasive particles are uneven, and the carcass is mainly controlled by the mechanical force of the diamond, the diamond cutting edge value is low, and the cutting efficiency is low. It is difficult to solve the issue of self-sharpening, and it is not possible to exert the effect of grinding each diamond, resulting in waste of raw materials. The principle of diamond brazing "brazing" is the use of brazing fillers containing active elements (such as Ti, Cr, W, etc.) to make the reactive elements chemically react with the diamond surface and form a layer of carbides during the brazing process. The role of layer carbide, diamond, matrix (brazing), and matrix can achieve a solid chemical metallurgical combination. Domestic brazing beads are mainly nickel-based or titanium-based brazing materials, and then sintered under vacuum conditions or argon atmosphere. At present, domestic enterprises mainly produce single-layer diamond brazing beads, and multi-layer diamond brazing beads have yet to be studied.
(2) Diamond Directional Arrangement Technology
In accordance with certain rules, diamonds are arranged in an orderly manner on the working lip surface. The arrangement distance between diamonds and diamonds and the arrangement rules are all controllable to meet the cutting requirements of different cutting objects. We will call this technique Directional arrangement for diamond technology. The methods for realizing the ordered diamond arrangement include template method, dispensing method and laser method. The latest practical method is to form the required regular arrangement of holes in the cold forming process of the carcass. The diameter of the hole is designed according to the coarsest grain size of the diamond coating, and it is automatically cold-pressed by an automatic cold press, and then the special shape is used. The special equipment will fill the diamond into the hole, and then cold pressing and then hot-press sintering. After the diamonds are arranged in an orderly manner on the working surface of the beading, the cutting efficiency and cutting life of the diamonds are greatly improved compared with the conventional beading, and the utilization rate of the diamonds is also greatly improved.
(3) comprehensive technology application
To sum up, the use of high-temperature brazing and diamond ordered arrangement of integrated manufacturing technology of beaded and pregnant inlaid sintering, electroplating bead comparison, has unparalleled advantages, especially in the application of small diameter beaded rope. The main advantages are as follows: 1 The diamond has a high exposed level, and the normal beaded diamond cutting edge height is limited to 1/3 of the abrasive grain height, while the brazed beading edge can reach a height of 2/3, with as high as 70% to 80%. The bare height of the diamond greatly expands the chip space and does not easily lead to chip failure and tool failure. 2 High cutting efficiency, the cutting efficiency of brazing type beads is 4 times that of ordinary sintered beads, and its strong chemical metallurgical combination is suitable for efficient grinding. 3 The utilization rate of diamond is high, the amount of diamond is reduced by half, and the cost is reduced, and the sawing life is equivalent to conventional beading. The application of brazing technology on small diameter beading can produce very good results. If the diameter of the carcass of the immersed sintered bead is reduced, it loses the characteristics of its multi-layered diamond, and the brazing technology can produce superior performance. The specifications are relatively small diamond beaded.

4 New series of diamond wire saws and new application extensions

(1) New Series of Diamond Wire Saw
Compared with the traditional diamond series wire saws (diameter is generally 58-512mm), the application of small diameter diamond wire saws (bead diameter is generally 55.5-57.5mm) forms a new series of diamond wire saws, which are mainly applied The area where the size of the slit is strictly required.
At the same time, the reduction of the bead diameter is of great significance to the cutting of precious stones. The application of small-diameter diamond wire saws in stone processing saves stone resources on the one hand, and reduces processing energy consumption on the other, making the processing methods more environmentally friendly. In order to meet the market demand, some domestic companies have now produced a variety of beaded ropes, and the smallest diameter has been able to achieve 56.0. To reduce the size of the rope saw, the diameter of the steel wire rope and the diamond bead must be reduced. The diameter of the wire rope used is generally only 53.5 to 53.8mm. Due to the reduction of cutting resistance, the small-diameter diamond wire saw can cut a large area (4m2) and thickness ( 5mm) Very thin granite plate, sawing efficiency increased by 3 times. The cutting force and energy consumption of the small-diameter wire saw is reduced by about 20% to 30% compared with the 59mm wire saw, and the cutting time per square meter is reduced by about 25%. Smaller diameter wire saws produce smaller dimensional deviations than large-diameter diamond wire saws, so they have some special properties. Currently, small-diameter beads are best produced by hot isostatic pressing (first cold pressing followed by hot isostatic pressing) or by brazing diamond. Reducing the diamond bead diameter is beneficial to increase productivity, reduce production costs, and has low noise, less pollution, and low energy consumption during use.
(2) new application of reinforced concrete cutting wire saw
At present, the domestic reinforced concrete rope saw technology has developed to a relatively mature stage, and the scope of practical use is continuously expanding. In addition to the traditional cutting of reinforced concrete structures, it also has large-scale applications in such fields as cutting of submarine cables, cutting of oil pipelines, cutting of large-scale steel and other metal structures, and transformation of boilers and smelting furnaces. The Harbin Engineering University and a domestic company have jointly developed submarine oil pipelines and cable pipe cutting wire saws and related equipment that have been used on a small scale; the transformation works of smelting furnaces in domestic large and medium-sized steel companies such as Shanghai Baosteel and Guangxi Liugang also A large number of diamond wire saws are used, which have the advantages of small kerfs, simple operation, environmental protection, and strong cutting ability of parts and the like, which can save a large number of transformation costs for enterprises.

5 Conclusion

Compared to other diamond tools, diamond wire saws are flexible tools. They not only can be used to cut straight plates, but also can cut special shaped plates. They are not restricted by the shape of the surface of the object. They require a simple work site and can be cut in large areas. The use of diamond wire saws can be used. Improve resource utilization and reduce environmental pollution. Due to these advantages, its market size is getting larger and larger and its application range is becoming wider and wider. With the advancement of technology, the use of powder granulation technology and automatic cold-pressing technology can greatly increase the production efficiency of diamond wire saws; adopting new technologies such as hot isostatic pressing technology, diamond orientation and brazing technology, and new technologies. The diamond wire saw produced by the method can greatly improve the overall performance of the wire saw, and the large-scale use of the high-performance diamond wire saw has very important significance for increasing the utilization rate of the stone resources, reducing the cutting cost per unit area and protecting the ecological environment.