Diamond saw blade is a cutting tool, widely used in the processing of hard and brittle materials such as stone and ceramics. The diamond saw blade is mainly composed of two parts; the base body and the cutter head. The base body is the main support part of the bond cutter head, and the cutter head It is the part that cuts during use. The cutter head will continue to be consumed during use, but the matrix will not. The reason why the cutter head can play the role of cutting is because it contains diamond, diamond is currently the hardest The material, which rubs and cuts the object to be machined in the cutter head, while the diamond particles are wrapped in metal inside the cutter head.
In the process of use, the metal matrix is consumed together with the diamond. Generally, the ideal situation is that the metal matrix is consumed faster than the diamond, so that both the sharpness of the cutter head and the longer life of the cutter head can be ensured.
Classification of diamond saw blades
More and more industries use diamond saw blades in the production process. With the integration of the industry, the types of diamond saw blades have become more refined.
A. Manufacturing process classification:
1. Sintered diamond saw blades: divided into cold-pressed sintering and hot-pressed sintering, and pressed and sintered.
2, welding diamond saw blade: high-frequency welding and laser welding two, high-frequency welding through the high-temperature melting of the welding head and the substrate together, laser welding through the high-temperature laser beam to the edge of the blade and the substrate contact to form a metallurgical melting .
3. Electroplated diamond saw blade: The cutter head powder is attached to the substrate by electroplating.
II. Appearance classification:
1. Continuous Edge Saw Blades: Continuous sawtooth diamond saw blades are generally produced by sintering method. Commonly used bronze binders are used as basic carcass materials. Water must be added to ensure the cutting effect, and the type of the slits can be cut with a laser.
2. Blade-type saw blade: Sawtooth disconnection, cutting speed, suitable for dry and wet cutting methods.
3. Turbine-type saw blade: Combining the advantages of the first and second items, the serration continuously exhibits a turbine-like uniform bump, which improves the cutting speed and increases the service life.
Different materials use different types of diamond saw blades. Different powder formulations are suitable for different material properties and have a direct impact on the quality, effectiveness, qualification rate, and even cost and benefits of the material products.
The factors influencing the efficiency and life of the diamond saw saw include sawing process parameters, diamond particle size, concentration, and binder hardness. According to the number of energy saw blade speed, sawing concentration and feed speed.
First, sawing parameters
(1) Line speed of the saw blade: In actual work, the linear speed of the diamond saw blade is limited by the equipment condition, the saw blade quality and the nature of the sawn stone. From the perspective of the best saw blade life and sawing efficiency, the linear speed of the saw blade should be selected according to the nature of different stone materials. When sawing granite, the blade speed can be selected in the range of 25m to 35m/s. For granites with high quartz content and difficult to saw, the lower limit of the blade speed is appropriate. In the production of granite tiles, the diameter of the diamond saw blade used is small and the line speed can reach 35m/s.
(2) Sawing depth: The sawing depth is an important parameter concerning diamond abrasion, effective sawing, the force condition of the saw blade and the nature of the sawed stone. In general, when the linear speed of the diamond circular saw blade is high, a small depth of cut should be selected. From the present technology, the depth of sawing diamond can be selected between 1 mm and 10 mm. When sawing a granite block with a large-diameter saw blade, the sawing depth can be controlled between 1 mm and 2 mm, and at the same time, the feed speed should be reduced. When the linear speed of the diamond saw blade is large, a large depth of cut should be selected. However, within the allowable range of saw performance and tool strength, it is necessary to take as much cutting concentration as possible to improve cutting efficiency. When there are requirements on the machined surface, small depths of cut should be used.
(3) Feed speed: The feed speed is the feed speed of sawing stone. Its size affects the sawing rate, blade force, and heat dissipation in the sawing area. Its value should be chosen according to the nature of the sawed stone. In general, sawing softer stones, such as marble, can increase the feed speed appropriately. If the feed speed is too low, it is more conducive to improving the sawing rate. Sawing of fine-grained, relatively homogenous granites can be used to properly increase the feed rate. If the feed rate is too low, the diamond blade can be easily ground. However, when sawing coarse and uneven soft and hard granite, the feeding speed should be reduced, otherwise it will cause vibration of the saw blade to cause diamond chipping and reduce the sawing rate. The cutting speed of sawing granite is generally within the range of 9m ~ 12m/min.
Second, other factors
(1) Diamond particle size: The commonly used diamond particle size is in the range of 30/35 to 60/80. The harder the rock, choose a finer grain size. Because under the same pressure conditions, the finer the diamond, the more conducive to cutting into hard rock. In addition, the general large-diameter saw blade requires a high cutting efficiency, and a coarser particle size, such as 30/40, 40/50, should be selected; the sawing efficiency of a small-diameter saw blade is low, and the rock sawing section is required to be smooth. Use finer particles, such as 50/60, 60/80.
(2) Cone concentration: The so-called diamond concentration refers to the density of diamonds distributed in the carcass of the working layer (ie, the weight of diamond contained in a unit area). "Specification" stipulates that when there are 4.4 carats of diamond per cubic centimeter of work carcass, the concentration is 100%, and when it contains 3.3 carats of diamond, the concentration is 75%. The volume concentration indicates the volume of diamond in the agglomerate, and specifies that when the volume of diamond accounts for 1/4 of the total volume, the concentration is 100%. Increasing the diamond concentration is expected to extend the life of the saw blade because increasing the concentration reduces the average cutting force per diamond. However, increasing the depth will inevitably increase the cost of the saw blade, so that there is a most economical concentration, and the concentration increases as the helium cut-off rate increases.
(3) Hardness of cutter head bond: Generally speaking, the higher the hardness of the bond, the stronger its anti-wear ability. Therefore, the hardness of the bonding agent should be high when sawing the rock with high abrasiveness; the hardness of the bonding agent should be low when sawing the soft rock material; when sawing the hard and abrasive rock, the hardness of the binding agent should be moderate .
(4) Force effect, temperature effect and abrasion damage: During the process of cutting the stone, the diamond circular saw blade will be subjected to alternating loads such as centrifugal force, sawing force and sawing heat.
Due to the force effect and temperature effect, the worn diamond saw blade was damaged.
Force effect: In the sawing process, the saw blade is subjected to axial force and tangential force. Due to the force acting in the circumferential direction and in the radial direction, the saw blade is wavy in the axial direction and is dished in the radial direction. Both of these deformations will cause the rock face to be not straight, the stone to be wasted, the noise during sawing, and the vibration to increase, resulting in early damage to the diamond agglomerate, and reduced blade life.
Temperature effect: The traditional theory holds that the influence of temperature on the saw blade process mainly manifests itself in two aspects: one is the graphitization of diamond in the agglomeration, and the other is that the diamond and the carcass have a hot enthalpy and cause the diamond particles to fall off prematurely. . New research shows that heat generated during the cutting process is mainly introduced into the agglomerate. Arc zone temperature is not high, generally between 40 ~ 120 °C. However, the temperature of the abrasive grain grinding point is relatively high, generally between 250 and 700°C. The cooling fluid only reduces the average temperature of the arc zone, but has little effect on the temperature of the abrasive particles. Such a temperature does not cause carbonization of the graphite, but it changes the frictional properties between the abrasive particles and the workpiece, and causes thermal stress between the diamond and the additive, resulting in the fundamental bending of the diamond failure mechanism. Studies have shown that the temperature effect is the most influential factor in breaking the saw blade.
Grinding damage: Due to the force effect and temperature, the saw blade will wear out after a period of use. The main forms of wear damage are the following: abrasive wear, partial crushing, large area crushing, shedding, mechanical abrasion in the direction of the cutting speed of the bonding agent. Abrasive wear: The diamond particles and the parts are constantly rubbing, and the edges passivate into a plane, losing the cutting performance and increasing the friction. The heat of sawing will cause a thin graphitized layer on the surface of the diamond particles. The hardness will be greatly reduced and the wear will be aggravated: the surface of the diamond particles will undergo alternating thermal stress, and at the same time, it will withstand the alternating cutting stress, and fatigue cracks will occur and the parts will be broken. The sharp new edges are the ideal wear patterns; large areas are broken: the diamond particles are subjected to impact loads when cutting in and out, the more prominent particles and grains are consumed prematurely; shedding: alternating cutting forces make the diamond The particles are constantly shaken in the binding agent and loosen. At the same time, the wear of the binder itself during sawing and the heat of sawing soften the binder. This reduces the holding power of the binding agent. When the cutting force on the particles is greater than the holding force, the diamond particles will fall off. Either type of wear is closely related to the load and temperature experienced by the diamond particles. Both of these depend on the cutting process and cooling lubrication conditions.
