Tribological Properties of Mo/NiCrBSi Thermal Spray Deposits

1998 ◽  
Author(s):  
V. Fervel ◽  
B. Normand ◽  
C. Coddet ◽  
M. Delaet
Keyword(s):  
Cast Iron ◽  
Adhesive Wear ◽  
Tribological Behavior ◽  
Optical Microscope ◽  
Atmospheric Plasma ◽  
Wear Process ◽  
Dry Conditions ◽  
Nicrbsi Coating ◽  
The Difference ◽  
Nicrbsi Coatings

Abstract The tribological behavior of Mo/NiCrBSi coatings obtained by atmospheric plasma spray was studied under dry conditions using an Amsler machine. Discussion is made on the effects of the plasma gas mixture and of the preheating of the substrate. The wear process of Mo/NiCrBSi in situation of dry rolling-sliding contact versus cast iron was observed using a profilometer, an optical microscope, and a scanning electron microscope. It was found that the wear mechanism could be divided into two steps : the first one corresponds to an abrasive wear; it results from the difference in hardness between the counter-specimen and the Mo/NiCrBSi coating. The second one corresponds to an adhesive wear resulting from the transfer of cast iron from the counter-specimen to the coating.

Formation of the Cast Iron Coatings Plasma-Sprayed at Different Substrate Temperatures

2010 ◽  
Vol 44-47 ◽  
pp. 2144-2147
Author(s):  
Ya Zhe Xing ◽  
Chao Ping Jiang ◽  
Hong Chen ◽  
Jian Min Hao
Keyword(s):  
Cast Iron ◽  
Substrate Temperature ◽  
Phase Structure ◽  
Processing Parameters ◽  
Optical Microscope ◽  
Atmospheric Plasma ◽  
Cross Sectional ◽  
The Cross ◽  
Plasma Sprayed ◽  
Iron Coatings

In this work, three cast iron coatings were produced by atmospheric plasma spraying. During spraying, the surface temperature of three coatings (substrate temperature) was controlled to be averagely 50oC, 180oC and 240oC by changing the processing parameters. X-ray diffraction (XRD) was employed to analyze the phase structure of the starting powder and the coatings. The results showed that the powder was mainly composed of (Fe,Cr)7C3 and martensite and both the spraying processing and the substrate temperature exerted no influence on coating phase structure. An optical microscope (OM) was used to characterize the microstructure of the cross-section and surface of the coatings. It was found that the cross sectional hardness increased with the increase of the substrate temperature due to the improvement in interlamellar bonding.

scholarly journals WEAR RESISTANCE OF ELECTRODEPOSITED Fe-W ALLOY COATINGS UNDER DRY CONDITIONS AND IN THE PRESENCE OF RAPESEED OIL

2018 ◽  
Vol 1 (1) ◽  
pp. 16-23 ◽  
Author(s):  
A. Nicolenco ◽  
N. Tsyntsaru ◽  
T. Matijošius ◽  
S. Asadauskas ◽  
H. Cesiulis
Keyword(s):  
Coefficient Of Friction ◽  
Wear Mechanism ◽  
Dry Friction ◽  
Rapeseed Oil ◽  
Wear Track ◽  
Adhesive Wear ◽  
Tribological Behavior ◽  
Wear Depth ◽  
Dry Conditions ◽  
Oil Films

Amorphous Fe-W alloys with 25 at.% of W were electrodeposited under direct and pulse modes from glycolate-citrate bath with and without addition of polyethylene glycol. The tribological behavior of the coatings was studied at 1, 2 and 5 N loads under dry friction and in the presence of rapeseed oil films of 0.2-5.0 m thickness. The tribological behavior of obtained coatings at dry friction reveals their severe tribo-oxidation resulting in a high wear depth and coefficient of friction. Observed groove like surface with well-adhered particles inside the wear track point out on abrasive-adhesive wear mechanism of Fe-W alloys. In the presence of rapeseed oil films the wear mechanism changes, and values of coefficient of friction decrease up to 10 times compared to dry friction conditions. The optimum thickness of rapeseed oil film was 1 μm. This film has the satisfactory adhesion and uniform distribution on the surface, and could withstand up to 2 000 cycles.

scholarly journals Microstructural Charactistics of Plasma Sprayed NiCrBSi Coatings and Their Wear and Corrosion Behaviors

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 170
Author(s):  
Songqiang Huang ◽  
Jingzhong Zhou ◽  
Kuoteng Sun ◽  
Hailiang Yang ◽  
Weichen Cai ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Acid Corrosion ◽  
Composite Coatings ◽  
Atmospheric Plasma ◽  
Confocal Laser ◽  
Formation Mechanisms ◽  
Temperature Oxidation ◽  
Surface Protection ◽  
Plasma Sprayed ◽  
Nicrbsi Coatings

Nickel-based alloys are commonly used as protective coating materials for surface protection applications owing to their superior resistance to corrosion, wear and high-temperature oxidation. It is urgent to study the fundamental mechanism between the structure and corrosion properties of the Nickel-base composite coatings. This paper, therefore, focuses on clarifying the mechanisms of the microstructure influencing the acid corrosion and mechanical characteristics of the as-sprayed NiCrBSi coating and post-heat-treated coating. The formation mechanisms of the amorphous phase of flat particles during the plasma spray process were studied by using X-ray diffraction analysis, Raman spectroscopy and confocal laser scanning microscope at first. Then the evolutionary process of the corrosion structure and phase of the coating in the accelerated corrosion experiment is directly visualized by using scanning electron microscopy and energy spectrum analysis. The mechanical properties of the amorphous NiCrBSi coatings are lastly measured by microhardness and friction wear tests. The critical phenomena and results help to elucidate the relative influence of the surface features of atmospheric plasma sprayed coatings on acid corrosion responses and wear resistance, aiming at contributing to the development of a protective technique for electrical engineering.

scholarly journals Meteorological conditions over Antarctic blue-ice areas and their influence on the local surface mass balance

2001 ◽  
Vol 47 (156) ◽  
pp. 37-50 ◽  
Author(s):  
Richard Bintanja ◽  
Carleen H. Reijmer
Keyword(s):  
Mass Balance ◽  
Low Frequency ◽  
Meteorological Conditions ◽  
Surface Mass Balance ◽  
Surface Mass ◽  
Wind Speeds ◽  
Dry Conditions ◽  
The Difference ◽  
Sublimation Rates ◽  
Different Characteristics

AbstractThis paper addresses the causes of the prevailing meteorological conditions observed over an Antarctic blue-ice area and their effect on the surface mass balance. Over blue-ice areas, net accumulation is zero and ablation occurs mainly through sublimation. Sublimation rates are much higher than over adjacent snowfields. The meteorological conditions favourable for high sublimation rates (warm, dry and gusty) are due to the specific orographic setting of this blue-ice area, with usually a steep upwind mountainous slope causing strong adiabatic heating. Diabatic warming due to radiation, and entrainment of warm air from aloft into the boundary layer augment the warming. The prevailing warm, dry conditions explain roughly 50% of the difference in sublimation, and the different characteristics of blue ice (mainly its lower albedo) the other 50%. Most of the annual sublimation (∼70%) takes place during the short summer (mainly in daytime), with winter ablation being restricted to occasional warm, dry föhn-like events. The additional moisture is effectively removed by entrainment and horizontal advection, which are maximum over the blue-ice area. Low-frequency turbulent motions induced by the upwind mountains enhance the vertical turbulent transports. Strong gusts and high peak wind speeds over blue-ice areas cause high potential snowdrift transports, which can easily remove the total precipitation, thereby maintaining zero accumulation.

Study and Researches about the Microhardness’s Variation of a Special S.G. Cast Iron

2010 ◽  
Vol 638-642 ◽  
pp. 1233-1236
Author(s):  
Ioan Milosan
Keyword(s):  
Cast Iron ◽  
Wear Surface ◽  
Wear Process

The paper presents some aspects about the influence of the heat treatment’s parameters over the microhardness’s variation of a Bainitic S.G. Cast Iron at the end of an wear process. It was determinate the variation of the rapport () between the microhardness ( H) and the distance of the wear surface (l).

scholarly journals Milksolids production from different combinations of perennial ryegrass and white clover cultivars: II Milksolids production and farm profitability

2001 ◽  
pp. 97-102 ◽  
Author(s):  
S.L. Woodward ◽  
K.A. Macdonald ◽  
W.A. Carter ◽  
J.P.J. Eerens ◽  
J.R. Crush
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Nutritive Value ◽  
Block Design ◽  
Previous Season ◽  
Farm Profitability ◽  
Dry Conditions ◽  
The Difference ◽  
Clover Content ◽  
Friesian Cows

1999/2000 and 2000/2001 were the first two complete seasons of a replicated farm systems trial designed to measure the effects on whole farm profitability (Economic Farm Surplus (EFS) of mixtures of ryegrasses and white clovers released on to the market recently, or at least 15 years ago, and rotationally grazed by dairy cows. All the pastures were sown in late autumn 1998. There were four treatments with all combinations of 1980s (80R), and late 1990s (98R) ryegrasses, and 1960s (60C)and late 1990s (98C) white clovers, each replicated 3.0 times in a randomised block design giving twelve 4-ha, self-contained farmlets stocked with three Friesian cows/ha. Milksolids production was unaffected by either ryegrass or clover cultivar age, but there was a significant ryegrass x clover cultivar interaction reflected as higher milksolids production on the 80R/98C treatment than the 98R/98C treatment in 1999/2000. This was a result of a higher clover content in the 80R/98C pastures compared with other treatments. Although the difference in clover content was still present in 2000/2001, the wetter summerÂ-autumn meant the ryegrass maintained a higher nutritive value than in the previous season under dry conditions, so clover content did not affect milksolids production in 2000/2001. There were no main treatment effects on EFS in either season, but there was a significant ryegrass x clover interaction in 1999/2000 shown as a higher EFS on the 80R/98C treatment than on the 98R/98C treatment. Keywords: cultivars, dairying, Economic Farm Surplus, milksolids, perennial ryegrass, white clover

scholarly journals Corrosion Mitigation of Gray Cast Iron and Aluminum in NaOH Using Water Hyacinth (Eichhornia crassipes) Plant Extract

2019 ◽  
pp. 1-15
Author(s):  
D. T. Oloruntoba ◽  
O. S. Adesina ◽  
O. F. Abraham ◽  
K. J. Akinluwade
Keyword(s):  
Cast Iron ◽  
Corrosion Rate ◽  
Water Hyacinth ◽  
Eichhornia Crassipes ◽  
Gray Cast Iron ◽  
Optical Microscope ◽  
Hot Water ◽  
Gray Cast ◽  
Plant Leaves ◽  
Inhibitor Efficiency

This research focused on the corrosion behavior of gray cast iron and aluminum in alkaline medium (0.5 M NaOH) with and without inhibitor (water hyacinth Eichhornia crassipes extract) of varying concentrations of 5%, 10%, 15%, 20% and 25%. The corrosion rates of the metal samples were investigated using the weight loss and electrochemical methods alongside the formulation of a dispersant using readily available chemicals to develop a colloidal solution of the extract produced by hot water digestion of the water hyacinth plant leaves. The metallography tests of control samples as well as the most and least corroded samples were carried out using Optical Microscope (OM). The results revealed that the aluminum resulted in minimum corrosion rate of 0.000483 mg/mm2/yr with inhibitor efficiency of 98.93% obtained for sample A5 (25% extract from water hyacinth) while for the gray cast iron, a minimum corrosion rate of -4.4E-05 mg/mm2/yr with inhibitor efficiency of 566.6% obtained for sample C3 (15% extract from water hyacinth). The electrochemical result of aluminum showed increase in corrosion potential from -1.494 VAg/AgCl to -1.482 V Ag/AgCl and that of gray cast iron from -0.5436 VAg/AgCl to -0.2839 VAg/AgCl upon increase in inhibitor concentration. Therefore, the use of water hyacinth (Eichhornia crassipes)extract reduced the corrosion or dissolution rate of gray cast iron and aluminum in (NaOH) sodium hydroxide medium.

Investigation of the friction behavior of plasma spray Mo/NiCrBSi coated brake discs

2021 ◽  
Vol 63 (3) ◽  
pp. 259-265
Author(s):  
Halil Kılıç ◽  
Cenk Mısırlı ◽  
İbrahim Mutlu
Keyword(s):  
Coefficient Of Friction ◽  
Plasma Spray ◽  
Wear Behavior ◽  
Atmospheric Plasma ◽  
Brake Disc ◽  
Friction Behavior ◽  
Braking Performance ◽  
Spray Process ◽  
The Coefficient Of Friction ◽  
Nicrbsi Coating

Abstract This paper presents the findings of comparative research conducted to find out the braking performance of a Mo/NiCrBSi coated automobile brake disc. The friction and wear behavior of the Mo/NiCrBSi coating (CD) used for the disc material was evaluated using a laboratory scale disc-pad dynamometer and compared with a reference disc (RD). The coating was deposited by means of the atmospheric plasma spray process on a grey cast iron substrate. Braking tests were performed according to the SAE-J2430 test standard. Disc microstructures were characterized by SEM and XRD. It was found that the bonding strength was good with an infinite rating between the accumulated coating layer and the substrate. The results show that the coated brake disc has a comparable coefficient of friction and that the amount of wear is lower than that of the reference disc. The addition of ductile phases to the disc coating was beneficial in reducing the coefficient of friction to an acceptable degree and also effectively improving wear resistance.

scholarly journals The Morphology Analysis of Plasma-Sprayed Cast Iron Splats at Different Substrate Temperatures via Fractal Dimension and Circularity Methods

2019 ◽  
Vol 38 (2019) ◽  
pp. 692-698
Author(s):  
Qiulan Wei ◽  
Li He ◽  
Zhang Liu ◽  
Xiao Feng ◽  
Ya-Zhe Xing
Keyword(s):  
Fractal Dimension ◽  
Cast Iron ◽  
Substrate Temperature ◽  
Solidification Rate ◽  
Molten Droplet ◽  
Characterization Methods ◽  
Different Temperatures ◽  
Molten Droplets ◽  
The Difference ◽  
Plasma Sprayed

AbstractPlasma-sprayed cast iron splats were deposited onto polished aluminum substrates preheated to different temperatures ranging from 25°C to 250°C. The morphology of single splat was observed by a field emission scanning electron microscope. Quantitative characterization methods, including fractal dimension (FD) and circularity analyses of the splat profile, were employed to identify the difference in morphology of the splats with the change of the substrate temperature. The results showed that the substrate temperature has a significant effect on the spreading of molten droplets and the morphology of resultant splats through changing the solidification rate of the droplets. With the increment of substrate temperature, the homogeneous and sufficient spreading of the droplets resulted from low solidification rate reduces the splashing of the droplets. In addition, the evaporation of adsorbed moisture on the substrate improves the wettability between the spreading droplet and the substrate, then benefits the homogeneous spreading of the molten droplet. As a result, a distinct decline in the FD value was observed. It was also suggested that the FD analysis could be used to characterize the morphology of the splat more effectively while the circularity method was heavily dependent on the area of the splat.

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