1. High voltage and large current density impact method. That is, the stainless steel castings in the early oxidation of the use of high-voltage shock, so that the parts have been oxidized by electric shock and then connected into pieces.
2. Surface grinding method. This method is to the polished aluminum mill filled with the oxidation of the gap left, so that the resulting gaps connected together as a bridge role.
3. Surface shot peening method. This method is to use a round head hammer to tap the gap, through the beat to make it closed, can achieve even the purpose of the film.