Force effect, temperature effect and wear damage of wet cutting diamond saw blade
In the process of cutting ceramic tile, the wet cutting diamond circular saw blade will be subjected to alternating loads such as centrifugal force, sawing force, and sawing heat, which will cause the wet cutting diamond circular saw blade to be damaged by grinding.
Force effect of diamond saw blade
In the process of sawing porcelain tile, the wet cutting diamond saw blade is subjected to the action of axial force and tangential force. Due to the presence of forces in the circumferential and radial directions, the saw blade is wavy in the axial direction and disc-shaped in the radial direction. These two kinds of deformation will cause uneven marble tile cutting surface, more ceramic tile waste, loud noise and increased vibration during sawing, resulting in early damage of diamond segments and reduced saw blade life.
Temperature effects during cutting
The traditional theory holds that the influence of temperature on the process of wet cutting diamond saw blade is mainly manifested in two aspects: one is to cause the stoneization of diamond in the segments. Second, the thermal stress between the diamond and the matrix causes the diamond particles to fall off prematurely. New research shows that the heat generated in the process of cutting porcelain tile is mainly transferred to the segments. The temperature of the arc zone is not high, generally between 40 and 120 °C. The abrasive grinding point temperature is relatively high, generally between 250 ~ 700 ℃. The coolant only reduces the average temperature of the arc zone, but has little effect on the temperature of the abrasive particles. Such a temperature will not cause carbonization of graphite, but will change the friction properties between the abrasive particles and the workpiece, and cause thermal stress between the diamond and the additive, resulting in fundamental bending of the failure mechanism of the diamond. Studies have shown that the temperature effect is the biggest factor affecting the breakage of wet cutting diamond saw blades.
wet cutting diamond saw blade wear and tear
Due to the force effect and temperature effect, the wet cutting diamond saw blade tends to be worn and damaged after a period of use. The main forms of abrasion damage are as follows: abrasive wear, local crushing, large-scale crushing, falling off, and mechanical abrasion of the binder in the direction of the sawing speed. Abrasive wear: The diamond particles are constantly rubbed against the marble tile, the edges are passivated into a flat surface, the cutting performance is lost, and the friction is increased; the heat of sawing will cause a graphitized thin layer on the surface of the diamond particles, which greatly reduces the hardness and aggravates the wear. Local breakage: The surface of diamond particles is subjected to alternating thermal stress and alternating cutting stress, and fatigue cracks will appear and local breakage will reveal sharp new edges, which is an ideal wear pattern. Large area crushing: The diamond particles are subjected to impact load when cutting in and out, and the more prominent particles and grains are consumed prematurely. Falling off: The alternating cutting force causes the diamond particles to be continuously shaken in the bond to loosen. At the same time, the abrasion of the binder itself and the heat of sawing during the process of sawing ceramic tile soften the binder. This reduces the holding force of the bond, and 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 to which the diamond particles are subjected. Both of these depend on the sawing process and cooling and lubrication conditions.
How to get the best cutting results with wet cutting diamond saw blades
When the wet cutting diamond saw blade cuts workpieces such as marble tile, concrete and ceramics, the diamond particles acting as a blade on the surface of the wet cutting diamond saw blade are firmly embedded in the matrix, and the diamond exposed on the surface of the saw blade continuously grinds the cutting surface of the workpiece so as to achieve high machining efficiency. Purpose. The surface diamond used for cutting will continue to wear during processing, and at the same time the wear of the matrix allows new diamond particles to be gradually exposed. In order to obtain the best cutting process conditions, the balance between tool life and cutting speed needs to be improved. Generally, for difficult-to-cut workpieces, high-strength diamond should be selected, and at the same time, the wear of the matrix should be coordinated with the wear of the diamond, so that the tool can be effectively cut and worn normally. For the diamond tool matrix, improper selection of diamond type, size and concentration can lead to abnormal tool wear or loss of cutting function.
Factors affecting the cutting performance of wet cutting diamond saw blades
In addition to diamond and matrix selection, there are several other factors that can have a very large impact on the sawing performance of the saw blade, including: ① the manufacturing method and process parameters of the segments or cutting edges; ② the performance of the workpiece; ③ sawing conditions ; ④ cooling efficiency; ⑤ bonding quality of segments and metal matrix; 6 structure and tension of metal matrix;
Wear of diamond blades
In order to facilitate the removal of chips, the cutting process parameters must be adapted to the performance of the cutting edge and the machined workpiece, so that the suspension is kept within a certain thickness, so as to avoid the substrate from being exposed to harsh wear conditions. The change of the cutting direction will also affect the performance of the tool, which should be properly adjusted according to the movement direction, saw blade specifications and technical parameters. The effect of the adjustment is twofold.
First, during the up and down cutting process, the relative direction of the resultant cutting force is different from that of the supporting frame. In the upward or downward cutting mode, when the resultant force deviates too much from the direction of maximum hardness, an unstable cutting state will occur, resulting in harmful vibrations in the process of cutting porcelain tile. If the spindle support force is in the vertical direction, increasing the ratio of the tangential force to the normal force will result in lower stability when cutting ceramic tile upwards, and the opposite effect when cutting marble tile downwards.
Second, when the blade rotates in the opposite direction, the diamond loading conditions will vary greatly. Under the condition that the porcelain tile is cut down, when the diamond is in contact with the ceramic tile, it will be pressed into the marble tile with the maximum depth. Subsequently, the diamond particles gradually stand out along the surface layer of the worn workpiece, and finally separate from the workpiece. Contrary to the downward cut, the diamond penetration depth gradually increases during the upward cut, and finally reaches a maximum value when it leaves the groove. It can be seen that when the saw blade is turned downward, it is easy to cause diamond chipping.
Experiments show that the wear pattern on the circumference of the wet cutting diamond saw blade also depends on the cutting method. When cutting upwards, the entire diamond segment is subject to wear at the same speed, while when cutting downwards, the wear speed of a single diamond segment varies, which tends to make the worn parts tend to the periphery of the wet cutting diamond saw blade, which is opposite to the direction of rotation. Due to the influence of the above reasons, the additional load of cutting diamond particles causes the cutting amount of the material to continuously increase in the orderly incisions, thereby forming a spiral wear process, which makes the following diamonds unable to participate in the cutting work.