Elektrodeposition Cr/Ni Pada Baja Karbon
Daftar Isi:
- Electrodeposition or electroplating is a process of coating metal with other metals in an electrolyte solution which is electrified. Electroplating process is widely used for the coating of chromium metal on carbon steel components because the process is cheap and simple. Nonetheless, the hydrogen gas that comes out when the electroplating process causes cracks in the chrome surface, causing the chrome surfaces prone to wear. Electro-deposition of multilayer Cr/Ni offering alternative methods to replace chrome coating. This research aims to develop methods electro-deposition to deposit a layer of Ni above the Cr layer using carbon steel metal. The influence of process parameters, namely the time of immersion of the layer thickness and the mechanical properties of the Ni layer was examined. The workpiece used as the parent metal was carbon steel ST 40 with diameter of 16 mm and a thickness of 3 mm. Electro-deposition of chrome is done by using a fixed time of 60 minutes and 6 volt voltage, whereas the nickel plating was done by varying the immersion time using 30, 45, 60, 90 and 120 minutes, with the same voltage of 2.8 volts. The composition of the electrolyte solution chromium per liter of distilled water was chromic acid (250 g/l), sulfuric acid (2.5 g/l) and KCN (10 g/l), while the solution of nickel was prepared by nickel sulfate (60 g/l), nickel chloride (18.75 g/l) and boric acid (13 g/l). The thickness measurement was conducted using an optical microscope type Euromax Holland and analysed using image raster software, the micro hardness testing was carried out using Vickers microhardness tester type TTS unlimited HWMMT-X7, and wear testing was done using test Ogoshi testing machine type OAT-U. The results showed that an increase in the immersion time produced an increase in the thickness and hardness of coating, but the wear area decreased. With the immersion time of 120 minutes the maximum thickness of Ni was 22.8 μm, hardness was 438.7 HV, and the wear area was 2.94 .