In practical work, the linear speed of marble saw blade is limited by equipment conditions, the quality of saw blade and the nature of sawn stone. In order to obtain the best service life and sawing efficiency of the saw blade, the linear speed of the saw blade should be selected according to the properties of different stones. When sawing granite, the linear speed of the saw blade can be selected in the range of 25m ~ 35m/s, and the lower limit of the linear speed of the saw blade should be selected for granite with high timely content which is difficult to cut. In the production of marble tiles, the diameter of diamond circular saw blade is small, and the linear speed can reach 35 m/s.
In the process of cutting stone, marble saw blade will be subjected to alternating loads such as centrifugal force, sawing force and sawing heat.
The wear of diamond circular saw blade is caused by force effect and temperature effect.
Force: During sawing, the saw blade is subjected to axial force and tangential force. Due to the circumferential and radial forces, the saw blade is wavy in the axial direction and disc-shaped in the radial direction. These two kinds of deformation will lead to uneven rock section, more waste of stone, loud noise and intensified vibration during sawing, which will lead to early damage of diamond aggregates and reduce the life of saw blades.
Temperature effect: the traditional theory holds that the influence of temperature on the saw blade process is mainly manifested in two aspects: first, it leads to graphitization of diamond in agglomeration; Secondly, the thermal stress between diamond and matrix leads to the premature shedding of diamond particles. New research shows that the heat generated in the cutting process is mainly transferred to caking. Arc temperature is not high, generally between 40 ~ 120℃. But the temperature of abrasive grinding point is relatively high, generally between 250 ~ 700℃. However, the cooling liquid only reduces the average temperature in the arc zone and has little effect on the abrasive temperature. Such a temperature will not carbonize graphite, but will change the friction performance between abrasive particles and workpiece, and cause thermal stress between diamond and additives, which will lead to a fundamental change in the failure mechanism of diamond. The research shows that the temperature effect is the biggest factor that damages the saw blade.
Wear: Because the force corresponds to the temperature, the marble saw blade often wears after being used for a period of time. The main forms of wear are: abrasive wear, local crushing, large-area crushing and falling off, and mechanical wear of bonding agent along the sawing speed direction. Abrasive wear: diamond particles constantly rub against the workpiece, and the edge is passivated into a plane, losing cutting performance and increasing friction. Sawing heat will cause graphitized thin layer on the surface of diamond particles, which will greatly reduce hardness and aggravate wear. When the surface of diamond particles is subjected to alternating thermal stress and alternating cutting stress, fatigue cracks will occur and local fractures will occur, exposing sharp new edges, which is an ideal wear form. Large-scale crushing: diamond particles bear impact load when cutting in and out, and the more prominent particles and grains are consumed prematurely; Falling off: alternating cutting force makes diamond particles shake constantly in the binder, resulting in looseness. At the same time, in the sawing process of marble saw blade, the wear of the adhesive itself and the sawing heat soften the adhesive. This reduces the holding power of the bonding agent, and when the cutting force on the particles is greater than the holding power, the diamond particles will fall off. No matter what kind of wear, it is closely related to the load and temperature borne by diamond particles. Both of them depend on the sawing process and cooling and lubrication conditions of the marble saw blade. Hubei Changli answers for you!