Production process of magnesium alloy etching plate

1. Potion preparation

Prepare etching solution:

If the concentration is 68% nitric acid, add about 20% (volume ratio) of the actual volume of nitric acid, that is, between 16 and 20L (generally, the actual volume is too large). The water level in the casing remains 1 cm above the vertical blade base. Ensure that the Baume degree of the acid solution is between 13-14 degrees at this time, and measure it with a special Baume meter. The amount of additives added should be slightly less than 5% (volume ratio), that is, slightly less than 4L, and 3-3.5L of special additives for magnesium boards can be used, and fine-tuned according to the actual etching effect. After adding, turn on the machine, heat up, and stir for 20-30 minutes.

  2. Corrosion principle

Since magnesium metal is relatively active, it can react quickly in a short time, which is its advantage over zinc and copper plates. It is easy to control. Therefore, the control of the corrosion process requires high refrigeration equipment. Most magnesium plate corrosion machines at home and abroad use cooling water circulation for refrigeration. There are less magnesium ions in the etching potion in the early stage, and the reaction is unstable. Therefore, it is recommended to use a small area of pre-coated board for etching. In this way, the corrosion heat release is less, the temperature is easy to control, and the board surface is not easy to burn through. After corroding about 3 pieces and the solution contains a small amount of magnesium ions, the corrosion process will be relatively stable. At this time, large-area plates can be used for production, which is stable and efficient until the activity of the liquid medicine decreases in the later stage of the solution. In the later stage, more acid should be added on the basis of the acid added in the early stage to maintain the activity of the potion, which can prolong the corrosion life and rot a few more boards.

         The method of adding acid: At the beginning of the learning stage, you should use an electronic scale to weigh each board before and after corrosion, record it, and add the corresponding acid before the next piece of corrosion. The amount of acid added should be the weight loss of the previous piece multiplied by 7 . For example, the weight of the previous plate is 500g before corrosion, and 300g after corrosion, and the weight loss is 200g. Before making the next plate, add 200*7=1400ml, that is, add 1.4L of nitric acid (68%). If it is an acid with a Baume degree of 33, you can add 1.4L*1.5=2.1L.

  3. The initial stage of potion corrosion

     For the first to third 1.5mm thick corroded plates, select a pre-coated magnesium plate with an area of less than 300mm*300mm. For the film, you need to select an embossed film or a film with a small corrosion area for exposure, then develop and etch. It is suggested that the first piece can directly corrode a bare plate with a size of about 300mm*300mm, which can make the potion more stable.