| AVS 62nd International Symposium & Exhibition | |
| Plasma Science and Technology | Thursday Sessions |
| Session PS-ThP |
| Session: | Plasma Science and Technology Poster Session |
| Presenter: | Petros Abraha, Meijo University, Japan |
| Correspondent: | Click to Email |
In this research, a customized equipment that utilizes electron beam gun and processing chamber with a meshed shielding grid that comprises of a discharge region, acceleration region and processing region is used to perform diffusion based nitriding treatment of steel components.
The electron beam gun starts discharge when an argon gas is introduced into the discharge region, and DC voltage is applied between the heated cathode and the discharge electrode. Argon is then ionized resulting in a large number of electrons in the discharge region. The electrons are then accelerated by the acceleration voltage Va applied between the discharge electrode and the anode. The generated electron beams are delivered into the processing chamber to produce nitrogen plasma. The plasma nitriding apparatus includes a meshed electrode mounted on the stage and electrically insulated from the processing chamber. The meshed shielding grid is made of stainless and formed into a cylindrical shape. The metal mesh is formed of a wire which has a diameter of 0.16 mm and having 40 meshes per inch. The sample to be treated is placed in the meshed electrode. The plasma nitriding apparatus includes a DC power supply device that bias the sample to a positive potential higher than the plasma potential at the location where the sample is set within the meshed shielding grid. The plasma nitriding apparatus also includes DC power supply that biases the meshed shielding grid to a negative potential.
The results of the nitrided samples, within the meshed shielding grid, for 3, 6, and 12 hours show that the treated surfaces were without any compound layer but composed of only diffusion layer whereby the measured thicknesses were about 45 μm, 65 μm and 90 μm respectively. For comparison, samples were treated under the same conditions but without the meshed shielding grid. The results reveal that in addition to the diffusion layer of about the same thickness, a 5 μm thick compound layer was formed in all three samples. This confirms that the meshed shielding grid is effective in diffusion based nitriding.