The general process of mechanical polishing

1. The surface of the rough-blasted milling, EDM, and grinding processes can be selected for polishing with rotating surface polishing machines or ultrasonic grinders rotating at 35 000-40 000 rpm. The commonly used method is to use a wheel of diameter Φ3mm, WA#400 to remove the white EDM layer. This is followed by manual whetstone grinding, strip whetstones with lubricants or coolants. The general order of use is #180 to #240 to #320 to #400 to #600 to #800 to #1000. Many mold makers choose to start with #400 in order to save time.

2. Semi-precision semi-precision casting mainly uses sandpaper and kerosene. The number of sandpaper is: #400 to #600 to #800 to #1000 to #1200 to #1500. In fact, #1500 sandpaper only uses die steel (52HRC or more) that is suitable for hardening, but it is not suitable for prehardened steel because it may cause surface burn of prehardened steel.

3, the use of diamond polishing paste. When polishing is performed using a polishing cloth wheel mixed with diamond abrasive powder or a polishing paste, the usual polishing sequence is 9 μm (#1800) to 6 μm (#3000) to 3 μm (#8000). 9μm diamond abrasive and polishing cloth wheel can be used to remove the hair-like grinding marks left by # 1200 and # 1500 sandpaper. Next, polishing was performed using a sticky felt and a diamond paste in the order of 1 μm (#14000) to 1/2 μm (#60000) to 1/4 μm (#100000). Accuracy requirements for polishing processes above 1μm (including 1μm) can be performed in a clean polishing chamber in a mold processing plant. For more precise polishing an absolutely clean space is required. Dust, smoke, dandruff, and saliva foam can all be scrapped off for high-precision polished surfaces after hours of work.