Multiple Needle Cathodes Plasma Surface Alloying of Ti6Al4V with W-Mo-C-N

2008 ◽  
Vol 373-374 ◽  
pp. 426-429
Author(s):  
Yue Fei Zhang ◽  
Xin Chao Bian ◽  
Qiang Chen ◽  
Guang Qiu Zhang ◽  
Yuan Gao
Keyword(s):  
Wear Resistance ◽  
Layer Structure ◽  
Surface Hardness ◽  
High Hardness ◽  
Surface Alloying ◽  
Cathode Plasma ◽  
Working Pressure ◽  
Plasma Surface ◽  
Pure Graphite ◽  
Plasma Surface Alloying

A multiple-needle-cathode plasma surface alloying process has been developed for improving the properties of surface hardness, wear resistance and corrosion resistance of Ti6Al4V. The process is carried out at temperatures below 800 °C and facilitates the simultaneous introduction of W, Mo,nitrogen and carbon into the surfaces of Ti6Al4V forming gradient alloying layer structure with an extremely high hardness. The process is performed at working pressure of 30Pa-80Pa with 9-needle-cathode of W80Mo20 alloy rods array and a high pure graphite plate cathode as target electrode. A maximum microhardness is 4-6 times much harder than the substrate. The results show the presence of carbide and nitride ceramics phases contribute to high microhardness and wear resistance. The multiple-needle-cathode discharge plasma treatment is an effective method for improvement of the mechanical and tribological properties of titanium-base alloys by formation of graded diffusion hard surface layers. The present paper describes this novel process and properties characteristics.

Low Temperature Plasma Surface Alloying of Austenitic Stainless Steels

2006 ◽  
Vol 118 ◽  
pp. 85-90 ◽  
Author(s):  
Y. Sun ◽  
E. Haruman
Keyword(s):  
Low Temperature ◽  
Stainless Steels ◽  
Layer Structure ◽  
Surface Hardness ◽  
Austenitic Stainless Steels ◽  
Low Temperature Plasma ◽  
Surface Alloying ◽  
Temperature Plasma ◽  
Plasma Surface ◽  
Plasma Surface Alloying

This paper gives a brief review on the three low temperature plasma surface alloying processes that have been developed in recent years to engineer the surfaces of austenitic stainless steels to achieve much enhanced surface hardness and wear resistance, without compromising their corrosion resistance. These include low temperature plasma nitriding, low temperature plasma carburizing and the newly developed hybrid process involving the simultaneous incorporation of nitrogen and carbon to form a dual layer structure. The processing, structural and property characteristics of each process are discussed briefly in this paper.

Tribological Performance of Ti6Al4V Alloy Treated by Plasma Surface Ni Alloying

2012 ◽  
Vol 509 ◽  
pp. 204-207
Author(s):  
Feng Zhang ◽  
Ze Ying Wang ◽  
Zhen Xia Wang ◽  
Zhi Yong He
Keyword(s):  
Wear Resistance ◽  
Wear Mechanisms ◽  
Tribological Property ◽  
Surface Hardness ◽  
Tribological Performance ◽  
Alloyed Layer ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Phase Constituent ◽  
Plasma Surface Alloying

Plasma surface alloying technology was applied to introduce Ni element into Ti6Al4V to improve its tribological property. The microstructure, composition, phase constituent and hardness of the alloyed layer were examined. Wear mechanisms were discussed on the basis of wear scar observations. The tribological performance of the alloyed layer was investigated by ball-on-disk sliding tests in different environments. The results showed that the Ti-Ni alloyed layer was about 12μm in thickness and the content of Ni element reached to 28% on the surface. The surface hardness of the layer was 677HV, nearly twice as the untreated Ti6Al4V. The wear resistance of the modified Ti6Al4V substrate was improved obviously in different environments.

scholarly journals A New Plasma Surface Alloying to Improve the Wear Resistance of the Metallic Card Clothing

2019 ◽  
Vol 9 (9) ◽  
pp. 1849 ◽  
Author(s):  
Dongbo Wei ◽  
Fengkun Li ◽  
Shuqin Li ◽  
Xiaohu Chen ◽  
Feng Ding ◽  
...  
Keyword(s):  
Wear Resistance ◽  
High Hardness ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Wear Rates ◽  
Before And After ◽  
Glow Plasma ◽  
Surface Morphologies ◽  
And Diffusion ◽  
Plasma Surface Alloying

A new surface strengthening process: Plasma surface chromizing was implemented on the metallic card clothing to improve its wear resistance based on double glow plasma surface metallurgy technology. A chromizing coating was prepared in the process, which consisted of a deposited layer and diffusion layer. The surface morphologies, microstructure, phase composition, and hardness were analyzed in detail. The friction behaviors of the metallic card clothing before and after plasma surface alloying were comparatively analyzed under various sliding speeds at room temperature. The results showed that: 1. The chromizing coating on the surface of metallic card clothing was dense and homogeneous without defects, and the metallic card clothing still maintained its integrity and sharpness. 2. The chromizing coating consist of [Fe,Cr], Cr, Cr23C6, and Cr7C3, which contribute to the high hardness. 3. The average microhardness of metallic card clothing increased from 365.4 HV0.05 to 564.9 HV0.05 after plasma surface chromizing. Nano hardness of the chromizing coating was approximately 1.87 times than the metallic card clothing. 4. At various sliding velocities of 2 m/min, 4 m/min, and 6 m/min, the specific wear rates of metallic card clothing were 16.38, 9.06 and 6.26 × 10−4·mm3·N−1·m−1, and the specific wear rates of metallic card clothing after plasma surface chromizing were 2.91, 3.30, and 2.95 × 10−4·mm3·N−1·m−1. Furthermore, the wear mechanism of the chromizing coating gradually changed from adhesive wear to abrasive wear as the sliding velocity increased. The results indicate that the wear resistance of metallic card clothing was improved obviously after plasma surface chromizing.

Plasma Surface Alloying W-Mo Low-Alloy HSS

2005 ◽  
Vol 475-479 ◽  
pp. 3955-3958
Author(s):  
Jin Yong Xu ◽  
Yan Ping Liu ◽  
Yuan Gao ◽  
Zhong Xu
Keyword(s):  
High Speed ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Alloying Elements ◽  
Work Piece ◽  
Test Results ◽  
Surface Alloying ◽  
Plasma Surface ◽  
The Common ◽  
Plasma Surface Alloying

The plasma surface alloying low-alloy high speed steel (HSS) is carried out in vacuum chamber where a source electrode (W-Mo) and a work piece are properly placed. By using the sputter of glow-discharge, under the common function of electric field and temperature field, ?????? the desired alloying elements (W- Mo) are sputtered from the source cathode, traveling toward the substrate. Subsequently the alloying elements deposit onto the surface of the substrate, forming alloy diffusion layer which the depth may vary from several micron to several hundreds micron. In the end a surface low-alloy HSS steel would be produced after ultra-saturation ion carbonization. The composition of the alloyed layer is equal or similar with it of low-alloy HSS. The carbonized layer, without coarse eutectic ledeburite structure, possesses high density of finely and dispersed alloy carbides with tungsten equivalent 10% above and a significant improvement in surface hardness and wear resistance. The principle of plasma surface alloying and its test results and commercial products application are introduced in this paper.

Features of Workpiece and Orificed Cathodes in Triple-Cathode Plasma Surface Alloying System

2012 ◽  
Vol 217-219 ◽  
pp. 1261-1264
Author(s):  
Xing Fu Rong ◽  
Shuo Rong ◽  
Zhi Yu Qin
Keyword(s):  
Hollow Cathode ◽  
Plasma Plume ◽  
Surface Alloying ◽  
Cathode Plasma ◽  
Plasma Surface ◽  
Alloying System ◽  
Current Densities ◽  
Plume Flow ◽  
Plasma Surface Alloying

The performing features of workpiece cathode (W electrode) and the orificed hollow cathode (P electrode) in the triple-cathode plasma surface alloying system are studied. Current densities of the W cathode and the P cathode are obtained under the conditions of the different voltages and the different chamber pressures, based on which current transmitting densities of the orifice of the P cathode are obtained and the conditions of plasma plume flow occurrences are, combined with the observe records of experiments, discussed and analyzed.

Study of High Co Superhard High Speed Steel Surface

2009 ◽  
Vol 610-613 ◽  
pp. 253-256
Author(s):  
Zhong Hou Li ◽  
Sha Sha Liu ◽  
Zhi Yong Cheng
Keyword(s):  
Surface Layer ◽  
High Speed ◽  
Steel Surface ◽  
High Surface ◽  
Surface Hardness ◽  
High Speed Steel ◽  
Low Alloy Steel ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Plasma Surface Alloying

Cobalt- superhard high speed steel layer has been formed on the surface of low alloy steel 20Cr2V by tungsten-molybdenum-cobalt plasma surface alloying and following plasma carbonizing. After plasma surface alloying, a homogeneous and dense surface alloying layer was formed, thickness of which is 200μm. Composition, microstructure and properties of the alloying layer were investigated. Contents of W, Mo, Co, Cr, V and C in the surface layer reach 8%,5%, 6% ,4%,1.5% and 1.5% or so respectively. The concentrations of alloy elements basically meet the requirements of high cobalt type superhard high speed steel. Constituent phases of the surface layer were martensite, M7C3 ,M2C and Cr3C2 carbides and μ phase after quenching treatment. The advanced gradient superhard high speed steel possesses not only high surface hardness, high anti-temper softening ability but also enough toughness.

Improvement in Wear and Corrosive Wear Resistance of Ti6Al4V Alloy by Double Glow Plasma Surface Alloying with W-Mo and W-Mo-N

2011 ◽  
Vol 675-677 ◽  
pp. 1253-1257 ◽  
Author(s):  
Chang Bin Tang ◽  
Dao Xin Liu ◽  
Fan Qiao Li ◽  
Bin Tang ◽  
Lin Qin
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Ambient Air ◽  
Corrosive Wear ◽  
Surface Alloying ◽  
Nacl Solution ◽  
Plasma Surface ◽  
Glow Plasma ◽  
Surface Modified ◽  
Plasma Surface Alloying

W-Mo and W-Mo-N surface-modified layers on Ti6Al4V alloy were obtained using a double glow plasma surface alloying technique. The morphology, microstructure, and chemical composition distribution of the modified layers were analyzed by scanning electron microscope, Xray diffraction, and glow discharge optical emission spectrometry. The hardness and toughness of the modified layers were measured using a micro-hardness tester, and dynamic repeating press equipment. The wear resistance in ambient air and the corrosive wear resistance in NaCl solution were evaluated using a ball-on-disk wear tester. The results show that W-Mo and W-Mo-N surface modified layers are composed of the alloying layers which vary in composition and phase form along the depth. A microhardness gradient was observed in the modified-surface layers. The surface hardness of the W-Mo-N and W-Mo modified layers was 25.3 and 14.2 GPa, which is seven-fold and 3.9-fold harder than the Ti6Al4V substrate, respectively. W-Mo and W-Mo-N surface-modified layers significantly improved the wear and corrosion resistance of Ti6Al4V. It seems that the wear resistance of W-Mo and W-Mo-N surface-modified layers in NaCl solution is better than that in ambient air owing to the strong lubricating effect of NaCl solution and the excellent corrosion resistance of the modified layers.

Tribological Performance of TiAl Based Alloy Treated with Plasma Surface Chromizing Process

2011 ◽  
Vol 189-193 ◽  
pp. 1091-1095
Author(s):  
Zhi Yong He ◽  
Zhen Xia Wang ◽  
Ying Qin Wang ◽  
Xiao Ping Liu ◽  
Zhong Xu
Keyword(s):  
Wear Resistance ◽  
Room Temperature ◽  
Surface Alloy ◽  
Wear Volume ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Sliding Test ◽  
Plasma Surface Alloying Technique ◽  
Plasma Surface Alloying ◽  
Wear Condition

TiAl-Cr alloy was prepared on surface of TiAl based alloy by plasma surface alloying technique. The wear resistance of the surface alloy was examined under various wear condition. During the room temperature ball-on-dic sliding test, the TiAl-Cr surface alloy showed reduced friction and improved wear resistance. For the 500°C sliding and room temperature fretting tests, the friction coefficient of TiAl-Cr surface alloy was a little higher than that of TiAl-based alloy, but the wear volume showed significant reducing, the wear resistance was improved obviously. The addition of chromium increases the strength and hardness of the TiAl-based alloy, and therefore the load bearing and anti-adhesion capacity of the surface were also enhanced, these were the main mechanisms for the improvement of wear resistance.

scholarly journals Microstructure and tribological behavior of W-Mo alloy coating on powder metallurgy gears based on double glow plasma surface alloying technology

2019 ◽  
Vol 55 (2) ◽  
pp. 227-234 ◽  
Author(s):  
D.-B. Wei ◽  
H.-X. Liang ◽  
S.-Q. Li ◽  
F.-K. Li ◽  
F. Ding ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Powder Metallurgy ◽  
Tribological Behavior ◽  
Alloy Coating ◽  
Nanoindentation Test ◽  
Surface Alloying ◽  
Plasma Surface ◽  
Before And After ◽  
Glow Plasma ◽  
Plasma Surface Alloying

In the present paper, plasma surface alloying was implemented on powder metallurgy gears to improve its wear resistance based on double glow plasma surface metallurgy technology. A W-Mo alloy coating was obtained in the process. The morphology, microstructure and phase composition were investigated by SEM, EDS and XRD. The hardness was examined by Vickers hardness test and nanoindentation test. The tribological behavior of powder metallurgy gears before and after plasma surface alloying was evaluated on a ball-on-disc reciprocating sliding tribometer under dry sliding condition at room temperature. The results indicate that the W-Mo alloy coating is homogeneous without defects, which includes deposition layer and interdiffusion layer. The average microhardness of powder metallurgy gears before and after plasma surface alloying is 145.8 HV0.1 and 344.4 HV0.1, respectively; Nano hardness of deposition layer and interdiffusion layer is 5.76 GPa, 14.35 GPa, respectively. The specific wear rate of W-Mo alloy coating is lower than original PM gears. The wear mechanism of W-Mo alloy coating is slight adhesive wear. The W-Mo alloy coating prepared by double glow plasma surface alloying technology can effectively improve wear resistance of powder metallurgy gears.

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