Polishing methods for zinc alloy die castings

Zinc alloy die casting parts before polishing, there will be serious cracks, bubbles, shrinkage holes, loose workpiece excluded, can be polished, polishing treatment.

The main purpose of polishing is to remove the surface burrs, parting lines, flares and other die-casting defects of the workpiece, and obtain a roughly flat and smooth surface. The cloth wheel is used for polishing. The diameter of the cloth wheel is 50 ~ 400mm, and the maximum circumferential speed is not greater than 2500m/min. The low speed of small parts is 1100 ~ 1400m/min. The adherent abrasive on the cloth wheel is 0.069 ~ 0.045mm, and the sharp Angle should be turned, and the iron oxide polishing paste should be used as the polishing accessory, and dry grinding should not be allowed. The grinding should be carried out in one direction, the grinding marks should not be crossed, and the grinding pressure should not be too large to avoid too much grinding.

The polished workpiece can be polished, and the polished workpiece should reach Ra0.025 ~ 0.05μm. Polishing application cloth wheel, non-stick abrasive, first with red polishing paste coarse throw, and then with white polishing paste (alumina) fine throw. The more light to use less polishing cream. , in order to avoid too much polishing paste, to cause difficulties in degreasing. But without polishing paste or polishing paste too little, will make parts surface overheating, pitting, electroplating is easy to produce bubbles. Polishing wheel speed should not be greater than 2150m/min, small parts in 1100 ~ 1600m/min. Polishing pressure can not be too large, pay attention to the amount of grinding, polishing should be carried out in one direction, wear marks can not cross. The polished parts shall be placed in the special workpiece appliance after inspection to prevent scratches.