Low-Temperature Nitriding of Pure Titanium by using Hollow Cathode RF-DC Plasma

4th International Conference on Advanced Materials Science and Technology

Windajanti, J.M.^1,2 ; Djoko, D.J.H.S.^1 ; Abdurrouf^1

Physics Department, University of Brawijaya, Jl. Veteran, Malang

65145, Indonesia^1

SMAK Santa Maria, Jl. Raya Langsep 41, Malang

65116, Indonesia^2

关键词: DC plasma;    Low temperature nitriding;    Low temperature plasma nitriding;    Low temperatures;    Nitrided specimens;    Nitriding process;    Pure titanium plates;    Sputtering process;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/202/1/012026/pdf
DOI  :  10.1088/1757-899X/202/1/012026

来源: IOP

【 摘 要 】

Pure titanium is widely used for the structures and mechanical parts due to its high strength, low density, and high corrosion resistance. Unfortunately, titanium products suffer from low hardness and low wear resistance. Titanium's surface can be modified by nitriding process to overcome such problems, which is commonly conducted at high temperature. Here, we report the low-temperature plasma nitriding process, where pure titanium was utilized by high-density RF-DC plasma combined with hollow cathode device. To this end, a pure titanium plate was set inside a hollow tube placed on the cathode plate. After heating to 450 °C, a pre-sputtering process was conducted for 1 hour to remove the oxide layer and activate the surface for nitriding. Plasma nitriding using N2/H2gasses was performed in 4 and 8 hours with the RF voltage of 250 V, DC bias of -500 to -600 V, and gas pressure of 75 to 30 Pa. To study the nitriding mechanism as well as the role of hollow cathode, the nitrided specimen was characterized by SEM, EDX, XRD, and micro-hardness equipment. The TiN compound was obtained with the diffusion zone of nitrogen until 5 μm thickness for 4 hours nitriding process, and 8 μm for 8 hours process. The average hardness also increased from 300 HV in the untreated specimen to 624 HV and 792 HV for 4 and 8 hours nitriding, respectively.