Today, Vibratory Finishing Machine suppliers share the causes of scratches on polished workpieces in grinders:
The first type of scratch conforms to the relative movement trajectory between the workpiece and the abrasive tool, and the number of scratches is relatively shallow, which is caused by unreasonable selection of process parameters or uneven distribution of abrasive grains on the abrasive tool. The height of the abrasive grain is not caused by the same, the specific analysis is as follows:
1. The abrasive grain size of the previous process is too large. Grinding processing generally uses two processes of roughing and finishing to complete the processing requirements of the workpiece. The purpose of roughing is to shorten the processing time as much as possible, improve the processing efficiency and reduce the processing cost. Therefore, the general roughing will use the abrasive with larger grain size to process. If the selection is not suitable, the particle size is too large, which will directly lead to the workpiece being The machined surface produces deep scratches that are not well repaired during subsequent finishing, affecting the accuracy of the surface quality.
2. Abrasive particles protrude from the surface of the abrasive. In the actual grinding process, the distribution of abrasive grains on the abrasive tool is not uniform, and the size of the abrasive grains is different, and the height of the distribution is not uniform, which leads to some obvious scratches during the grinding process. Such scratches and grinding motion tracks Consistent and more frequent occurrences during the grinding process. Combined with the microscopic map of the surface of the workpiece in the previous test, it is not difficult to analyze that the protruding abrasive particles are the main reason for the formation of deep scratches on the surface of the workpiece.
The second type is a special scratch, the number of scratches is small, and the depth is more obvious. The cause has certain contingency and randomness, and has little relationship with the selection of process parameters. The reasons for the analysis may be:
1. Impurities in the coolant. In order to ensure the surface quality and reduce the temperature of the processing area, the fixed abrasive grinding process needs to be cooled. In this paper, water cooling is used. Since the coolant is not filtered before the test, it will certainly contain some hard particles with a relatively large diameter. The surface creates a deep random scratch.
2. Grinding generated grinding debris. The grinding debris generated by the workpiece during grinding is not easily broken, and the coolant cannot wash away the grinding debris from the surface of the workpiece in time, so that the abrasive chips are embedded in the bonding agent between the abrasive grains, and as the grinding continues They will accumulate and accumulate. The particles with the larger stroke will participate in the grinding process, and the deep groove will be drawn on the surface of the workpiece. When it falls off, the surface of the tool will be drawn deeper. Random scratches that affect the quality of the ground surface.
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