scholarly journals Predicting Surface Hardness of Commercially Pure Titanium Under Plasma Nitrocarburizing Based on Experimental Data

Author(s):  
A S Darmawan ◽  
W A Siswanto ◽  
P I Purboputro ◽  
B W Febriantoko ◽  
T Sujitno ◽  
...  
2013 ◽  
Vol 789 ◽  
pp. 347-351 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Waluyo Adi Siswanto ◽  
Tjipto Sujitno

Commercially pure (cp) titanium has a relative soft hardness property. In particular usage such as sliding, the improvement of the surface hardness will be required. In this study, surface hardness improvement of cp titanium by Plasma Nitrocarburizing and Ion Implantation are compared. Plasma Nitrocarburizing processes are conducted at different elevated temperatures with different duration processes, i.e. at 350 °C for 3, 4, and 5 hours, and at 450 °C for 2, 3, and 4 hours respectively, while Ion Implantation processes are conducted at room temperature and process durations are varied as 2.3 hours, 4.7 hours, and 9.3 hours. Nitrogen ions are used to implant the material. Hardness tests are then performed on each specimen by using Micro Vickers Hardness Tester. The surface hardness number (HV) for specimens of the Plasma Nitrocarburizing processes at temperature of 350 °C for process duration of 3 hours, 4 hours, and 5 hours are 74.16, 92.25 and 94.41, respectively while those at temperature of 450 °C for duration process of 2 hours, 3 hours, and 4 hours are 103.70, 121.31 and 126.17, respectively. The processes of Ion Implantation produce the surface hardness number (HV) of 88.97, 125.51, and 130.2, for duration processes of 2.3 hours, 4.7 hours, and 9.3 hours. The process of Ion Implantation produce higher surface hardness number than the Plasma Nitrocarburizing process at temperature 350 °C but the surface hardness number is lower when compared to the Plasma Nitrocarburizing at a temperature of 450 °C. For the duration processes 4 hours and more, the process of Ion Implantation produces the same surface hardness number with the Plasma Nitrocarburizing at temperature of 450 °C.


2013 ◽  
Vol 315 ◽  
pp. 700-704 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Waluyo Adi Siswanto ◽  
Tjipto Sujitno

Commercially pure (cp) titanium is a relative soft metal and easily broken on friction-wear applications. To improve the hardness of the surface while maintaining the original properties, plasma nitrocarburizing process has been conducted. The effects of the treatment in different temperatures to the surface harness are then studied. In this study, cp titanium plasma nitrocarburizing process is conducted at different temperatures with different process time, i.e. at 350 °C for 3, 4, and 5 hours, and at 450 °C for 2, 3, and 4 hours respectively. Hardness tests are then performed on each specimen by using Micro Vickers Hardness Tester. The hardness values for the plasma specimens nitrocarburizing processes at temperature of 350 °C for process duration of 3 hours, 4 hours, and 5 hours are 74.16 HV, 92.25 HV and 94.41 HV, respectively, while for processes at temperature of 450 °C, the hardness values are 103.70 HV, 121.31 HV, and 126.17 HV for process duration of 2 hours, 3 hours, and 4 hours respectively. Hardness value of specimens which are resulted from the plasma nitrocarburizing process at temperature of 450 °C is higher compared with specimens that are processed at temperature of 350 °C.


2018 ◽  
Vol 781 ◽  
pp. 101-107
Author(s):  
Yurii Ivanov ◽  
Olga V. Krysina ◽  
Pavel Moskvin ◽  
Elizaveta A. Petrikova ◽  
Olga V. Ivanova ◽  
...  

Commercially pure A7 aluminum was exposed to surface modification in a single vacuum cycle which included vacuum arc evaporation and deposition of commercially pure titanium and intense electron beam irradiation and melting of the film–substrate system using a plasma-cathode pulsed electron source. The deposited Ti film thickness was 0.5 and 1 μm. The irradiated Ti–Al system revealed a multilayer multiphase structure consisting of submicro-and nanosized elements with intermetallic inclusions Al3Ti, Al2Ti, and TiAl3. The Ti film during irradiation broke up into fragments with their immersion in the molten Al surface layer to a depth of 20 μm. The modified material surpassed the initial aluminum in wear resistance by a factor of 2.4 and in microhardness by a factor larger than 4. The main cause for the high surface hardness and high wear resistance of the modified aluminum was likely the formation of both the intermetallic particles and the Ti-hardened transition layer.


2019 ◽  
Vol 71 (10) ◽  
pp. 1166-1176
Author(s):  
Onur Çomakli ◽  
Mustafa Yazici ◽  
Tuba Yetim ◽  
Fatih Yetim ◽  
Ayhan Celik

Purpose This paper aims to investigate the structural, tribological and electrochemical properties of Ag2O, ZnO, NiO coatings and Ag2O/ZnO/NiO nanocomposite films deposited on commercially pure titanium. Design/methodology/approach Ceramic thin films (Ag2O, ZnO, NiO coatings and Ag2O/ZnO/NiO nanocomposite film) were deposited on commercially pure titanium (CP-Ti) substrate. Surface characterization of the uncoated and coated samples was made by structural surveys (scanning electron microscopic examinations and X-ray diffraction analyses), hardness measurements, tribological and corrosion experiments. Findings Results were indicated that sol-gel coatings improved the wear and corrosion resistance of CP-Ti, and the best results were seen at the nanocomposite coating. It may be attributed to its small grain size, high surface hardness and high film thickness. Originality/value This study can be a practical reference and offers insight into the influence of nanocomposite ceramic films on the increase of hardness, tribological and corrosion performance. Also, the paper displayed a promising approach to produce Ag2O/ZnO/NiO nanocomposite coating on commercially pure titanium implants for biomedical applications.


Author(s):  
Natthaphong KONKHUNTHOT ◽  
Patcharanut BURANAPIMA ◽  
Patipan BOONNITEE ◽  
Mahamasuhaimi MASAE ◽  
Peerawas KONGSONG

In the present work, pack carburization with rubberwood charcoal and rubberwood ash at 925 °C for 6, 12, and 24 h was carried out to improve the surface hardness of commercially pure titanium (CP-Ti).  X-ray diffraction and energy dispersive spectrometer analyses revealed the formation of titanium carbide (TiC) and the existence of oxygen diffusion in the carburized surface. The surface hardness of most optimized conditions has remarkably increased by 481 % as compared to untreated CP-Ti (from 175 HV to 1016 HV) due to the TiC surface layer, while the hardened oxygen diffusion layer of about 300 μm in-depth, as clearly seen in the microhardness profiles is useful for increased load-bearing capacity. Consequently, pack carburization with rubberwood charcoal and rubberwood ash is a promising surface modification technique, which can significantly enhance the surface hardness and increase the load-bearing capacity of CP-Ti for biomedical and tribological applications. HIGHLIGHTS Rubberwood charcoal and ash are a new carbon source to fabricate the TiC layer on CP-Ti. Formation of the TiC layer remarkably enhances the surface hardness of CP-Ti by 481 %. The hardened oxygen diffusion layer is beneficial to load-bearing and anti-wear capacity. GRAPHICAL ABSTRACT


2017 ◽  
Vol 36 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Ilhan Çelik

AbstractTitanium and its alloys are widely used in many fields, including aerospace and the chemical and biomedical industries. This is due to their mechanical properties, excellent corrosion resistance, and biocompatibility although they do have poor wear resistance. In this study, a duplex layer was successfully formed on the commercially pure titanium surface by duplex treatments (plasma nitriding and physical vapor deposition (PVD)). In the initial treatment, plasma nitriding was performed on the pure titanium samples and in the second treatment, the nitrided samples were coated with CrN by PVD. The friction and wear properties of the duplex-treated samples were investigated for tribological applications. Surface morphology and microstructure of the duplex-treated samples were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, the tribological properties were investigated using pin-on-disc tribometer. A compound layer composed of ε-Ti2N and δ-TiN phases and a diffusion layer formed under the compound layer were obtained on the surface of pure titanium after the nitriding treatments. CrN coated on the nitrided surface provided an increase in the surface hardness and in the wear resistance.


1994 ◽  
Vol 353 ◽  
Author(s):  
Toshiaki Amano ◽  
Yoichi Kojima ◽  
Shigeo Tsujikawa

AbstractThe repassivation potentials, Er.crev’s, for metal/metal-crevice of Alloy 625 were determined in 0.3–10% NaCl solutions for temperatures up to 250 C. The Er.crev’s were found to be the least noble at temperatures around 100 and 125 C. The Er.crev became more noble as temperature increased; this tendency was particularly strong in diluted solutions. Based on the experimental data, a crevice corrosion map showing the critical condition in terms of temperature and NaCl concentration was presented. As for the map, a wide repassivation region was found in elevated temperatures, similar to that of commercially pure titanium, C.P.Ti.


2007 ◽  
Vol 336-338 ◽  
pp. 1148-1150
Author(s):  
Jian Bin Zhang ◽  
Ding Fan ◽  
Jing Jie Dai ◽  
Yao Ning Sun

Laser surface alloying is an attractive processing to improve surface hardness, wear and corrosion resistance. In this paper, a continuous wave CO2 laser was used to irradiate commercially pure titanium surface with pre-placed active carbon powders in argon atmosphere. A compact, well-adherent, and crack-free TiC/Ti composite layer was obtained. The microstructure and phase constitution of the alloyed layers were determined and analyzed, and the micro-hardness was measured. The result of X ray diffraction (XRD) analysis shows that the alloyed layers contain TiC and Ti (martensite). The scanning electron microscopy (SEM) observation shows TiC growth morphologies have a well-developed dendrite, cellular dendrite, globular microstructure and cross-petal microstructure. The mechanism of the formation of titanium carbides is discussed. Micro-hardness of the laser surface alloyed layer was improved to 420 Hv as compared to 200 Hv of the as-received commercially pure titanium.


2019 ◽  
Vol 961 ◽  
pp. 97-106 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Waluyo Adi Siswanto ◽  
Bambang Waluyo Febriantoko ◽  
Abdul Hamid ◽  
Tjipto Sujitno

One of the surface treatments to improve the hardness of the surface is by ion implantation process. This paper presents an equation to predict the surface hardness with the variable of the process time in ion implantation surface treatment. The hardness of three surfaces data were collected experimentally from various process times, i.e. 140 minutes, 280 minutes and 560 minutes. Lagrange polynomial interpolation was then used to generate quadratic mathematical formula of the surface hardness based on experimental data. The verification results show that the proposed equation accurately predict the surface hardness of commercially pure (cp) titanium under ion implantation process with the error less than 0.5 %. This equation can be used to set the appropriate treatment process time to achieve the expected surface hardness without costly trial experimental settings.


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