What is the formation mechanism of blockage and passivation of grinding wheels?
Embedded blockage is mainly caused by the mechanical infiltration of grinding debris into the gaps of the grinding wheel, where there is no chemical adhesion between the debris and the abrasive particles. The formation process of adhesive blockage is the chemical bonding between abrasives and grinding particles, and then the abrasives fuse with each other under mechanical adhesion and pressure when grinding carbon steel. When the abrasives rub or grind on the metal surface, the wear of the abrasives begins, that is, the sharp edges of the abrasives begin to be ground away, forming a flat surface on the abrasives. The plane becomes larger and larger, so that the frictional force acting on the abrasive grains is large enough to cause the sand particles on the surface of the grinding wheel to fall off or break, thereby exposing new grinding edges. At this point, the blockage of the grinding wheel is an embedded blockage formed by the embedding of grinding debris in the gap.
When grinding titanium alloy before grinding, the debris quickly adheres to the top of the abrasive grains. With the development of this adhesive, as it grows, the working abrasive particles, adhesive, and the surface of the gaps are all encapsulated by the adhesive. At this point, the grinding conditions deteriorate, the grinding force and heat increase dramatically, and the surface quality of the workpiece also deteriorates. When the grinding force continues to increase to a certain range, the adhered debris and abrasive grains fall off together, exposing new abrasive grain surfaces that adhere to the new abrasive grains again.
During this process, the cutting edge of the abrasive grain is almost completely covered by debris without any signs of wear. In this situation of blockage and passivation, in order to continue grinding, whether it is dressing the grinding wheel or forcibly squeezing out the surface sand particles, there will be accelerated wear of the grinding wheel. This is the adhesive blockage of chip fusion on the grinding particles and binders, which is the main reason why titanium alloys have a low grinding ratio during grinding.