The influence factors of diamond blade efficiency and life are cutting technological parameter, grit of diamond, concentration, bond hardness, etc.
The cutting parameter are blade RPM, cutting concentration and feeding speed.
1. Cutting parameter:
(1)The linear speed of blade: In practical work, the linear speed of blade is limited by equipment conditions, quality of blade and stone material. From best blade cutting life and cutting efficiency, to select linear speed of blade based on different stone nature.
When cutting the granite, the linear speed of blade shall be selected within the range of 25m-35m/s.
For granite with high quartz content and hard cutting, the linear speed of blade shall be taken in lower limit.
For producing tile of granite, the diameter of used blade shall be smaller, and linear speed can be reached to 35m/s.
(2)Cutting depth: cutting depth is related to diamond abrasion, effective cutting, blade stress condition, stone nature and more important parameter. Generally, when it is higher linear speed on diamond saw blade, to select small cutting depth, From current technology, the depth of cutting blade shall be chosen between 1mm-10mm.
Normally, the big diameter blade to cut granite block, the cutting depth shall be controlled between 1mm-2mm, and reduce the feeding speed. When it is a large linear speed of diamond blade, select the big cutting depth.
But, when the saw machine performance and blade strength in permission range, select big cutting depth for improving cutting efficiency.
When there is a request on processing surface, shall adopt small cutting depth.
(3)Feeding speed: the feeding speed is the feeding speed of cutting stone. Its size effect the cutting efficiency, blade stress and cooling conditions of blade area. Its value shall be chosen as per stone nature. Generally, cut soft stone, like marble, shall increase the feeding speed, if the feeding speed is lower, it will be better to improve the cutting efficiency.
To cut fine grain structure and homogeneous granite, shall increase the feeding speed, if the feeding speed is lower, the segment will be easy to be wear. But to cut rough grain structure and uneven soft and hard granite, shall reduce feeding speed, otherwise, which might cause blade shake and lead to diamond broken to reduce cutting efficiency.
The feeding speed of cutting granite is normally selected between the range of 9m-12m/min.
2. Other influencing factors
(1)Diamond grit: the common diamond grits is in the range of 30/35-60/80.
if the stone is harder, should select fine grit. Because in the same pressure condition, diamond the finer the sharper, to the benefit of cutting hard stone. Furthermore, generally it has the request of high cutting efficiency on big diameter blade, should select rough grits, such as 30/40, 40/50; the small diameter blade has lower cutting efficiency, and require stone cross-section smooth, should select fine grits, such as 50/60, 60/80.
(2)Segment concentration: The segment concentration is the diamond distribution density in working-level is bond (mean Unit area contained the weight of diamond). Standard provide that it is with a 4.4 carat diamond per centimeter in working bond, the concentration is 100%, and when it contain 3.3 carat, the concentration is 75%.
Volume concentration is said how many percentage of diamond in volume of segment, and provide the concentration is 100% when the diamond volume occupy 1/4 of total volume. Increase the diamond concentration is expected to extend the life of blade, because of the increased concentration that reduce the average cutting force of each diamond, but increase the depth will be surely to add the cost of blade, and thus, there is a most economical concentration, and the concentration will increase with high cutting efficiency.
(3)Hardness of segment bond: Generally, the higher hardness of bond, and the higher wear resistance ability. So, when cut the high abrasive stone, the hardness of bond shall be higher; when cut softer stone, the hardness of bond shall be lower; when cut high abrasive and hard stone, the hardness of bond shall be medium.
(4)Force effects, temperature effects and grinding damage: diamond circular saw blades in the process of cutting stone, will be subject to centrifugal force, cutting force, cutting heat alternating the role of the load. Force and temperature effects caused by the diamond saw blade worn to donate loss.
(a)Force effect: in the sawing process, the blade is subject to axial force and the role of tangential force. In the circumferential direction and radial force exists, making the saw blade in the axial wavy dish in the radial direction. Both deformation will result in the rock section is not straight, stone waste, cutting noise, vibration intensified, resulting in the early diamond agglomerate breakage, lower the saw blade life.
(b)Temperature effect: the traditional theory: the impact of temperature on the process of cutting is mainly in two aspects: First, to cause the agglomeration of diamond graphitization; secondly, heat force caused by the diamond and matrix and diamond particles prematureoff.
The new study shows that: the heat generated in the cutting process incoming agglomeration. Arc temperature is not high, generally between 40-120 Degrees C. Abrasive grinding point temperature is higher, generally between 250-700 Degrees C. Cooling liquid only reduce the average temperature of the arc zone, abrasive temperature was less affected.
So the temperature does not result in a graphite charring, but cause friction between the abrasive and the workpiece performance changes, and between the diamond and additives, thermal stress, which led to the fundamental bending of diamond failure mechanism.
It indicates that the temperature effect is to make the biggest impact of blade breakage.
(c)Grinding damage: because of the force and temperature stree, the saw blade will wear damage after a period of cutting. Grinding damage in the form of the following: abrasive wear, local crushing, crushing a large area, off, binder along the mechanical abrasion of cutting speed direction
. Abrasive wear: diamond particles constant friction with style pieces, edge passivation into the plane, loss of cutting performance, and increase friction. Cutting heat will make the diamond particle surface a thin layer of graphitization, the hardness is greatly reduced, and increased wear: diamond particle surface is subjected to alternating thermal stress, but also to withstand the stress of alternating cutting, there will be fatigue crack partially broken, revealing a sharp new edge, is an ideal wear pattern; large area of broken: the diamond particles in Qie Ruqie withstand the impact load, the more outsanding particles and grain consumed prematurely; off: alternating cutting force so that the diamond particles in the binder is shaking then cause loose. At the same time, the binding agent in the sawing process wear and cutting heat to soften the binder. This makes the holding force of the binder decreased, when the cutting force on the particles is greater than the holding force, the diamond particles will fall off. No matter what kind of wear of the diamond particles to bear the load and temperature are closely related. Both of which depend on the cutting process and the cooling and lubrication conditions.