Speaker
Description
Electrolytic polishing and etching is a finishing method that removes material from a metal or alloy through an anodic dissolution process. A sample is placed as an anode in an electrolytic cell and the electrolysis produces a surface suitable for metallographic analysis. The polishing process is characterized by the elimination of surface roughness and the formation of smooth and bright surfaces. Etching can often be performed in the same electrolyte by simply reducing the applied voltage to 10 percent of that required for polishing. The method is widely used in industry because of its simplicity and ability to polish complex shapes. Manufacturers of metallographic equipment present their products as automated. Only the electrolysis process itself is automated. After finishing, the sample must be immediately removed manually by the operator and cleaned. This process is critical with regard to the quality of the final sample surface and safety, because hazardous substances are often handled. The robot is placed next to a electrolytic equipment and handle all sample movements and cleaning in the ultrasonic bath in this experiment. The samples are made from ER308LSi austenitic stainless steel using 3D printing by Wire Arc Additive Manufacturing (WAAM). The final surface is achieved electrolytically on the commercial equipment. The samples handled by a metallographer in one case and a robotic arm in the other. The aim of the experiment is to compare the microstructure, especially with regard to the possibility of distinguishing delta ferrite. The surface is characterized using various microscopic techniques. Robotization can be the key to improving surface quality and safety.