Five Measures to Reduce Molding Processing Flaws

As an important tool for workpiece manufacturing, flaws are inevitable that may lead to bad effect. To better produce workpiece, there are five measures to solve the problem.

1. Choose and maintain the right grinding wheel. White corundum grinding wheel is the best choice. Its performance is hard and brittle, and is prone to new cutting edge, so the cutting force is small, the grinding heat is small. Using medium granularity on granularity such as 46 ~ 60 mesh is better, on the grinding wheel hardness by using soft and soft (ZR1, ZR2 and R1, R2), namely, coarse granularity, low hardness of the grinding wheel, good self excitation can reduce heat cutting. selecting the appropriate fine grinding wheel is very important, in view of the condition of the die steel with high vanadium high molybdenum, GD is suitable for single crystal corundum grinding wheel. when processing hard alloy, high quenching hardness of materials, the priority of using organic binder diamond grinding wheel, the organic binder grinding wheel grinding workpiece roughness of Ra0.2 mum.

2. Use cooling lubricant reasonably. Cooling, washing and lubrication should play three roles: keep clean, cooling and lubrication to control of grinding heat within the scope of the permit, to prevent thermal deformation. Improve the cooling conditions when grinding, such as by oil immersion wheel or inner cooling grinding wheel and other measures. Bring the cutting fluid into the center of the grinding wheel, cutting fluid can be directly into the grinding zone, giving play to the role of effective cooling, prevent workpiece surface burn.

3. After heat treatment of quenching stress reduced to a minimum, which may lead to reticular tissue under the action of the grinding force, carbide organization transformation to make the workpiece to produce cracks. For high precision mould, in order to eliminate the residual stress of the grinding, the grinding should be done after aging treatment of metal in order to improve the toughness at low temperature.

4. Adopt electrolytic grinding processing, improve the mould manufacturing precision and surface quality. Electrolytic grinding, grinding wheel shaving oxide film: instead of grinding, metal and small grinding force, grinding heat is small which won't produce the phenomenon such as grinding burrs, cracks, burns, surface roughness can be better than general Ra0.16 microns; In addition, the grinding wheel wear small, such as grinding hard alloy, silicon carbide grinding wheel wear is about for grinding of cemented carbide of the weight of 400%-600%, electrolytic grinding, grinding wheel wear is only hard alloy grinding in addition amount of 50%-100%.

5. Reasonable selection of grinding dosage, the use of small radial feeding method of fine grinding and fine grinding. Such as appropriate to reduce the radial feeding and grinding wheel speed, increase axial feeding, reduce grinding wheel and workpiece contact area, cooling condition is improved, so as to effectively control the improvement of surface temperature.