If the above-mentioned blocking factors affecting the flow exist, the flow speed will be reduced. Therefore, it is not enough to use flow agent to detect the change of flow rate just by looking at the pressure gauge. The concentration is an important index in the grinding wheel technical specification of superhard abrasive. Industry often misunderstands the concentration of 100 as 100%. In fact, the definition of concentration of 100 is that there are 72 carats of abrasive in a volume of 1 cubic inch. Therefore, the concentration of 50 refers to 36 carats of abrasive per cubic inch.
There are many kinds of abrasive grain sizes, and the abrasive with different grain sizes can have the same concentration. Now we compare the two abrasive grain sizes with the same concentration of 75. One is 60 grain size (American standard, the same below), and the other is 200 grain size. The abrasive content per cubic inch is 54 carats. For 60 grain size abrasive, there are 6900 grains per carat, while for 200 grain size abrasive; there are 262000 grains per carat.
Therefore, there are 372600 abrasive grains per cubic inch of grinding wheel for 60 grain size abrasive, and 14148000 abrasive grains for 200 grain size abrasive. Different abrasive particle sizes mean that the number of fine (left) particles is more than that of coarse particles at the same concentration.
Assuming that the abrasive particles are uniformly distributed in the grinding wheel, the number of abrasive particles per cubic inch can be obtained by cubic dividing the number of abrasive particles per cubic inch. For 60 grain size, it is 72 grains per inch, while for 200 grain size, it is 242 grains per inch. The reciprocal of the above figures is the abrasive grain spacing. For 60 grain size, the spacing is 0.014”, and for 200 grain size, the spacing is 0.004”.
If the length of cutting arc in grinding is 0.013”, the abrasive spacing of 60 grit grinding wheel is longer than it, so sometimes there is no abrasive working on the cutting arc, while for 200 grit grinding wheel, the abrasive spacing is 0.004”. Therefore, at least 3 abrasive grains are working on the cutting arc. From the above comparison, a common rule is drawn, that is, when selecting the grinding wheel, it is necessary to ensure that 4~10 abrasive grains are working on the cutting arc length.
Post time: Feb-20-2023