Lapping and ultra lapping are final machining process with the ball, level higher than G40 steel ball processing general to adopt ultra lapping process. The final ball size deviation, geometric accuracy and surface roughness, surface quality and burns and other technical requirements, to achieve the rules of the lapping or ultra lapping process procedure.
Check the diameter of the steel ball deviation and geometric accuracy, must be in the provision of special measuring instrument. After lapping of workpiece surface roughness and surface quality inspection, generally USES in astigmatism lamp under visual inspection. If controversial, but check under 90 times the magnifying glass, and with the corresponding standard photographs. After lapping processing of the workpiece surface quality and surface roughness of inspection, must take a certain number of artifacts under 90 times the magnifying glass and standard photo reference check. The surface roughness visual when in doubt, can be on the surface roughness instrument for testing.
Lapping and ultra lapping burn inspection methods using random sampling sampling, sampling observation of quality and quantity standards should comply with the regulations of burn standard.
The surface roughness is bad reasons:
1. The processing capacity is too little, processing time is too short.
2. The grinding disc groove is too shallow, groove and the contact surface of workpiece is too small.
3. Too high or uneven hardness, the hardness of grinding disc and trachoma and porosity, etc.
4. Paste is overmuch, the dosage or abrasive grain size too coarse.
5. Grinding disc groove is too dirty, with iron or other material.
Local surface roughness is bad reasons: rotating grinding disc groove shallow, workpiece contact area is too small. The Angle of the grinding disc groove is too small, make the workpiece rotation is not flexible; Small grinding pressure of the plate, sliding between the workpiece and the grinding disc.
YouYan injury is also a kind of surface imperfections, often appear in the circulation process, serious when can obviously see that there are certain depth under diffused light of potholes. Slight astigmatism only see a black or yellow light. But at 90 times the magnifying glass can see pits, its lower part is rough, scratches. Reasons are: grinding disc groove two-tone, artifacts due to low pressure in the deep groove, sometimes stay sometimes slip, the workpiece in contact with the grinding disc is grind; Grinding disc groove wall appeared impellers will grind workpiece.
