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Contact: Shao man
1. Cutting parameters.
(1) saw blade linear speed: in actual work, the linear velocity of diamond circular saw blade is limited by the equipment condition, the quality of the saw blade and the nature of the sawing stone. In terms of the service life and sawing efficiency of the best saw blade, the linear velocity of the saw blade should be selected according to the quality of the stone. Saw blade linear velocity can be selected within 25m ~ 35m/s. For granite with high quartz content and difficult to cut, the speed of sawblade linear velocity is the best. In the production of granite face brick, the diameter of diamond circular saw blade is relatively small, and the linear velocity can reach 35m/s.
(2) sawing depth: the cutting depth is an important parameter that not only involves diamond grinding, effective sawing, force of saw blade, and the nature of cutting stone. Generally speaking, when the linear velocity of diamond circular saw blade is relatively high, small cutting depth should be selected. From present technology, the depth of cutting diamond can be selected between 1mm ~ 10mm. The cutting depth can be controlled between 1mm ~ 2mm, and the cutting speed should be reduced at the same time. When the linear velocity of diamond circular saw blade is relatively large, large cutting depth should be selected. However, as far as the overall performance of the sawing machine and the scope of the tool strength permit, the larger cutting concentration should be used for cutting, so as to improve the cutting efficiency. When there is a requirement on the machining surface, small depth cutting should be adopted.
(3) feed speed: the feed speed is the feed speed of cutting stone. Its size affects the cutting rate, the force of the saw blade and the heat dissipation of the sawing area. Its value should be selected according to the nature of cut stone. Generally speaking, sawing more soft stone, such as marble, can increase the speed of the feed, if the speed of the knife is too low, it is better to improve the sawing rate. It can be used to improve the speed of feed. If the cutting speed is too low, the diamond blade can be easily polished. However, the cutting speed should be reduced when the coarse grain structure is uneven, or the cutting rate will be reduced due to the vibration of the saw blade. The feed speed of sawing granite is generally selected in the range of 9m ~ 12m/min.
2. Other influencing factors.
(1) diamond granularity: frequently used diamond particle size is within the range of 30/35 ~ 60/80. The harder the rock, the finer grain size. Because under the same pressure conditions, the diamond is finer and sharper, which helps to cut into the hard rock. In addition, generally large diameter saw blades require high cutting efficiency, which should be selected with coarser grain size, such as 30/40, 40/50; The small diameter saw blade has a low efficiency, which requires a smooth cutting section of the rock, which is suitable for fine particle size, such as 50/60,60/80.
(2) head concentration: the so-called diamond concentration refers to the density of the diamond in the working layer (i.e. the weight of the diamond in the relevant unit area). The "specification" stipulates that the concentration of diamonds containing 4.4 carats per cubic centimeter is about 100 percentage points, and the concentration is 75 percentage points. The volume concentration clearly indicates the volume of the diamond in the lumps, and stipulates that when the volume of diamond is 1/4 of the total volume, the concentration is 100 percentage points. Increasing the concentration of diamond can prolong the life of the saw blade, because the increase of the concentration is to reduce the average cutting force of each diamond. But enhance the depth of blades must enhance the cost of raw materials, thus the concentration of one of the most economic, and the concentration Cheng cut rate increases.
(3) the hardness of the combination of blade and head: in general, the higher the hardness of the binder, the stronger the resistance to wear. As a result, when sawing and grinding large rocks, the bond hardness is high; When sawing material soft rock, the bond hardness is low; When sawing and grinding large and hard rock, the bond hardness is appropriate.
(4) force effect, temperature effect and wear damage: diamond circular saw blade is affected by centrifugal force, sawing force, sawing heat and other alternating loads when cutting stone material.
Because of the force effect and temperature effect, the diamond circular saw blade is worn.
Force effect: when cutting, the saw blade should be positive to axial force and tangential force. Because of the positive effect of the force on the circumferential direction and radial force, the saw blade is wavy in the axial direction. These two kinds of deformation will result in the uneven surface of the rock, the waste of stone, the loud noise and vibration of the sawing, resulting in the early damage of the diamond and the reduced life of the saw blade.
Temperature effect: the traditional theory holds that the influence of temperature on the sawblade process is mainly reflected in two aspects: first, the diamond graphitization in the block; The second is to cause the heat of the diamond and the body heat and lead to the premature loss of diamond particles. New research shows that the heat generated when cutting is mainly passed into clumps. The arc zone is not very hot, usually between 40 and 120 degrees Celsius. The grinding point temperature is higher, usually between 250 and 700 degrees Celsius. The cooling liquid only reduces the average temperature of the arc zone, but it has little effect on the grinding temperature. That not make the graphite carbonization temperature, however, can make the friction between abrasive grain and workpiece change overall performance, and thermal stress occurred between diamond and additives, and to have led to the failure mechanism of diamond radically bending. The study shows that the temperature effect is the most important factor that causes the blade breakage.
Abrasion: because of force effect and temperature, the use of sawblade for a period of time often produces wear and tear. There are several types of abrasion: abrasive wear, local crushing, large range crushing, falling off, and mechanical abrasion along the cutting speed. Abrasive wear: constant friction between diamond particles and components, the edge passivating into a plane, losing the overall performance of cutting and increasing friction. Cutting heat can make the diamond particle surface graphitization thin layer, high hardness, aggravate wear: diamond particles surface under alternating thermal stress, as well as cutting under alternating stress, fatigue cracks will occur and local breakage and show new sharp edge, is the ideal wear form; Large range crushing: the diamond particles bear the impact load when cutting, and the prominent grains and grains are consumed prematurely. Shedding: the alternating cutting force causes the diamond particles to be shaken continuously in the binder. At the same time, the wear and sawing heat of the binder itself soften the binding agent. This reduces the control power of the binder, and when the cutting force on the particle is greater than the control force, the diamond particles will fall off. Any kind of wear is closely related to the load and temperature of the diamond particles. Both depend on the cutting process and the cooling and lubrication conditions.