1. The basic procedures of mechanical polishing. To obtain high-quality polishing results, the most important thing is to have high-quality polishing tools and auxiliary products such as oilstone, sandpaper and abrasive paste. The most important thing is a polished working environment, which requires a dust-free workshop. The choice of polishing procedure depends on the surface condition of the pre-processing, such as machining, EDM, grinding and so on.
2. The general process of mechanical polishing is as follows:
1. The surface after rough polishing, fine milling, electric spark, grinding and other processes can be polished by a rotating surface polishing machine or an ultrasonic grinder with a speed of 35000-40000rpm. The commonly used method is to use a diameter of 3mm, WA#400 wheels to remove the white electric spark layer. Then there is manual whetstone grinding, and the strips of whetstone are added with kerosene as a lubricant or coolant. The general order of use is #180-#240-#400-#600-#1000. Many mold manufacturers choose to start with #400 in order to save time.
3. Sandpaper and kerosene are mainly used for semi-precision polishing. The number of sandpaper is: #400-#600-#800-#1000-#1200-#1500. In fact, #1500 sandpaper is only suitable for hardened die steel (above 52HRC), not for pre-hardened steel, because it may cause burns on the surface of pre-hardened steel.
4. Fine polishing mainly uses diamond grinding paste. If the usual grinding order is 9um(#1800)-6um(#3000)-um(8000). 9um diamond abrasive paste and polishing cloth wheel can be used to remove hair-like wear marks left by #1200 and #1500 sandpaper. Then use sticky felt and diamond paste for polishing, the order is 1um(#14000)-1/2um(60000)-1/4um(#100000). The polishing process with precision requirements above 1um (including the number 1um) must have a clean space in the polishing of the mold. Dust, smoke, dandruff, and drool may all scrap the high-precision polished surface obtained after hours of work.