Properties of TiC-Ni Based Coatings Deposited by Different HVOF Spraying

2000 ◽  
Author(s):  
P. Vuoristo ◽  
M. Väisänen ◽  
T. Mäntylä ◽  
L.-M. Berger
Keyword(s):  
Wear Resistance ◽  
Flame Temperature ◽  
Oxygen Flow ◽  
Spray Parameters ◽  
Coating Properties ◽  
Hvof Spraying ◽  
Fuel Gas ◽  
Wear Rates ◽  
Operation Conditions ◽  
Satisfactory Coating

Abstract Hardmetal-like coatings of the TiC-Ni system are potential for use as wear, corrosion and heat resistant coatings in various operation conditions. Our previous works [1-12] have shown that these materials are well sprayable using different thermal spray processes such as plasma, D-Gun and HVOF spraying. Since HVOF spraying is today the most important process used to apply carbide based coatings, this study was carried out in order to evaluate more systematically the sprayability of these novel spray powders and the influence of HVOF spray parameters on some coating properties. Coating samples were prepared by using DJ Hybrid gun with propane as a fuel gas, and a CDS gun with hydrogen fuel gas. Oxygen flow rate was varied in both cases for changing the flame temperature. Microstructure, phase composition, hardness, and abrasion wear resistance of the coated samples were investigated. The results showed that both HVOF processes used give satisfactory coating properties and that the use of high oxygen flow rates is beneficial for improving the wear resistance of the coatings. Powders with fine particle size are beneficial in the DJ Hybrid process; the use of coarse powders results in coatings with somewhat higher wear rates. The optimum spray condition for the TiC-Ni system powders differs from that typically used for conventional WC-Co and Cr3C2-NiCr powders by a higher flame temperature.

Production and Characterization of HVOF Sprayed NiCr-TiC Coatings Using SHS Powder Feedstock

2000 ◽  
Author(s):  
M.T. Blatchford ◽  
A.J. Horlock ◽  
D.G. McCartney ◽  
P.H. Shipway ◽  
J.V. Wood
Keyword(s):  
Thermal Spraying ◽  
Xrd Analysis ◽  
Powder Size ◽  
Coating Properties ◽  
X Ray Diffraction ◽  
Hvof Spraying ◽  
X Ray ◽  
Wear Rates ◽  
Powder Feedstock

Abstract In this paper, the production of NiCr-TiC powder by SHS, suitable for HVOF spraying, is discussed together with results on the microstructure and coating properties. Compacts for SHS were prepared by mixing elemental Ti and C with pre-alloyed Ni-20wt.% Cr powder to give an overall composition of 35wt.% NiCr and 65wt.% TiC. These were then ignited and a self-sustaining reaction proceeded to completion. Reacted compacts were crushed, sieved, and classified to give feedstock powders in size ranges of 10-45 µm and 45-75 µm. All powder was characterized prior to spraying based on particle size distribution, x-ray diffraction (XRD), and scanning electron microscopy (SEM/EDS). Thermal spraying was performed using both H2 and C3H6 as fuel gases in a UTP/Miller Thermal HVOF system. The resulting coatings were characterized by SEM and XRD analysis, and the microstructures correlated with powder size and spray conditions. Abrasive wear was determined by a modified 'dry sand rubber wheel' (DSRW) test and wear rates were measured. It has been found that wear rates comparable to those of HVOF sprayed WC-17wt% Co coatings can be achieved.

Effect of Powder Type on the Relationship between Spray Parameters and Properties of HVOF Sprayed Cr3C2-NiCr Coatings

1998 ◽  
Author(s):  
C.J. Li ◽  
G.-C. Ji ◽  
Y.-Y. Wang ◽  
K. Sonoya
Keyword(s):  
Abrasive Wear ◽  
Gas Flow ◽  
Design Method ◽  
Spray Parameters ◽  
Wear Properties ◽  
Hvof Spraying ◽  
Wear Performance ◽  
Fuel Gas ◽  
Hvof Spray ◽  
Powder Type

Abstract The effects of powder types and HVOF spray systems used to produce Cr3C2-NiCr coating on the relationships between spray parameters and wear performance were investigated based on the effect of fuel gas conditions on abrasive wear and erosion wear. The relationships between spray parameters and wear properties were obtained by orthogonal regression experimental design method. Four types of powders and two HVOF spray systems were used. It is found that with the increase in fuel gas flow or pressure the abrasive wear and erosion of Cr3C2-NiCr coatings change following a concave curve. The Cr3C2-NiCr coating with the best wear performance will be deposited under intermediate fuel gas condition. It is experimentally confirmed that by different types of powders and HVOF systems applicable to HVOF spraying of Cr3C2-NiCr coating, although the optimized fuel gas conditions to deposit coating with the best wear performance will be influenced by types of starting powders.

scholarly journals Properties of Journal Bearing Materials That Determine Their Wear Resistance on the Example of Aluminum-Based Alloys

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 535
Author(s):  
Alexander Mironov ◽  
Iosif Gershman ◽  
Eugeniy Gershman ◽  
Pavel Podrabinnik ◽  
Ekaterina Kuznetsova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Journal Bearing ◽  
Tribological Behavior ◽  
Secondary Structures ◽  
Magnesium Content ◽  
Wear Rates ◽  
Relative Extension ◽  
Bearing Materials ◽  
Antifriction Alloys

Potential relations of tribological characteristics of aluminum antifriction alloys with their compositions and mechanical properties were investigated. In this regard, the properties of eight aluminum alloys containing tin from 5.4% to 11% doped with lead, copper, silicon, zinc, magnesium, and titanium were studied. Mechanical properties such as hardness, strength, relative extension, and impact strength were analyzed. Within the tribological tests seizure load and wear of material were evaluated and secondary structures were studied afterwards. The absence of a definitive correlation between tribological behavior and mechanical properties was shown. It was determined that doping tin over 6% is excessive. The seizure load of the alloys increases with the magnesium content. Secondary structures of the alloys with higher wear rates contain one order less magnesium and tin.

scholarly journals Effects of Alkyl-Substituted Polybenzoxazines on Tribological Properties of Non-Asbestos Composite Friction Materials

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 567
Author(s):  
Anun Wongpayakyotin ◽  
Chanchira Jubsilp ◽  
Sunan Tiptipakorn ◽  
Phattarin Mora ◽  
Christopher W. Bielawski ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Composite Materials ◽  
Coefficient Of Friction ◽  
Aromatic Amines ◽  
Underlying Structure ◽  
Methyl Groups ◽  
Friction Materials ◽  
Wear Rates ◽  
Structure Properties ◽  
Crosslink Densities

A series of substituted polybenzoxazines was synthesized and studied as binders in non-asbestos friction composite materials. The structures of the polybenzoxazines were varied in a systemic fashion by increasing the number and position of pendant alkyl (methyl) groups and was accomplished using the respective aromatic amines during the polymer synthesis step. By investigating the key thermomechanical and tribological characteristics displayed by the composite materials, the underlying structure-properties relationships were deconvoluted. Composite friction materials with higher thermomechanical and wear resistance properties were obtained from polybenzoxazines with relatively high crosslink densities. In contrast, polybenzoxazines with relatively low crosslink densities afforded composite friction materials with an improved coefficient of friction values and specific wear rates.

scholarly journals The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 670
Author(s):  
Gifty Oppong Boakye ◽  
Arna María Ormsdóttir ◽  
Baldur Geir Gunnarsson ◽  
Sandeep Irukuvarghula ◽  
Raja Khan ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Complex Geometry ◽  
Corrosion And Wear ◽  
Functional Layer ◽  
Scaling Properties ◽  
Wear Rates ◽  
Mechanical And Tribological Properties ◽  
Duplex Coating ◽  
Wear Protection

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.

Surface Wear Improvement of Al-Alloys by Amorphous Iron-Based Flame-Sprayed Coatings

2011 ◽  
Vol 690 ◽  
pp. 405-408 ◽  
Author(s):  
Joel Voyer
Keyword(s):  
Wear Resistance ◽  
Flame Spraying ◽  
Flame Spray ◽  
Phase Content ◽  
Coating Properties ◽  
Amorphous Iron ◽  
Spray Process ◽  
Spraying Parameters ◽  
Iron Based ◽  
Sprayed Coatings

Partially amorphous iron-based coatings were produced onto aluminium using a powder flame-spraying process with a commercially available feedstock powder (Nanosteel SHS-7170) obtained from the Nanosteel Company Inc.. Several coating properties such as the microstructure, porosity, phase content, micro-hardness, and wear resistance were evaluated in the as-sprayed condition. As shown by the results obtained, the powder flame iron-based coatings perform relatively well in term of wear resistance in comparison with similar coatings produced using other expensive thermal spray techniques. Furthermore, this study shows that all the coating properties (microstructure, porosity, phase content, hardness and wear performance) depend strongly on the flame spraying parameters used. Finally, this paper demonstrates clearly that the flame-spray process may be used to produce amorphous iron-based coatings having a good wear resistance, and that this process appears to be a suitable inexpensive alternative to plasma or HVOF processes based on the present results.

Thick Si-doped DLC coatings with high load bearing capacity on cold working tool steels by PECVD

2021 ◽  
pp. 1-19
Author(s):  
Xinyu Wang ◽  
Xudong Sui ◽  
Shuaituo Zhang ◽  
Mingming Yan ◽  
Yan Lu ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Cold Working ◽  
Chemical Vapor ◽  
Tool Steels ◽  
Dlc Coatings ◽  
Wear Rates ◽  
Si Doped ◽  
Silicon Doped ◽  
Hydrogenated Amorphous ◽  
Degree Of Graphitization

Abstract For improving the wear resistance, thick silicon doped hydrogenated amorphous carbon (a-SiC:H) coatings were deposited on cold working tool steels by Plasma Enhanced Chemical Vapor Deposition (PECVD) technology. The increase of the acetylene (C2H2) flow rate distinctly tuned the microstructure of a-SiC:H coatings, including an increase in the coating thickness (>15 μm), a decrease in the silicon content, a greater sp2/sp3 ratio and higher degree of graphitization. The highest hardness of 19.61 GPa and the greatest critical load of 50.7 N were obtained. The coating showed low wear rates against different friction pairs and presented excellent abrasive wear resistance at high applied load and the wear rates decreased with increasing loads, which exhibited an outstanding application prospect in cold working tool steels.

Formation of Structure of HVOF Sprayed WC-Co Coating on a Copper Substrate

1997 ◽  
Author(s):  
V.V. Sobolev ◽  
J.M. Guilemany ◽  
J.A. Calero
Keyword(s):  
Crystalline Structure ◽  
Substrate Surface ◽  
Copper Substrate ◽  
Interfacial Region ◽  
Solidification Velocity ◽  
Spray Parameters ◽  
Hvof Spraying ◽  
Mechanisms Of Development ◽  
Oxygen Fuel ◽  
Cooling Velocity

Abstract Mathematical modelling of the formation of the WC-Co coating structure and adhesion on copper substrate during high velocity oxygen-fuel (HVOF) spraying is provided. Smooth (polished) and rough (grit blasted) substrates are considered. Variations of solidification time, solidification velocity, thermal gradient, and cooling velocity in the coating and substrate interfacial region are studied. Formation of the amorphous and crystalline structures in the coating and of the crystalline structure in the substrate interfacial region is investigated. Behaviour of the crystal size and intercrystalline distance with respect to the thermal spray parameters and morphology of the substrate surface is analysed. Optimal conditions for the development of fine and dense crystalline structure are determined. Mechanical and thermal mechanisms of development of the substrate-coating adhesion are discussed. Results obtained agree well with experimental data.

scholarly journals Simulation of Neutron/Self-Emitted Gamma Attenuation and Effects of Silane Surface Treatment on Mechanical and Wear Resistance Properties of Sm2O3/UHMWPE Composites

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3390
Author(s):  
Donruedee Toyen ◽  
Yupadee Paopun ◽  
Dararat Changjan ◽  
Ekachai Wimolmala ◽  
Sithipong Mahathanabodee ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wear Resistance ◽  
Surface Treatment ◽  
Gamma Rays ◽  
Surface Hardness ◽  
Thermal Neutrons ◽  
Simulation Code ◽  
Neutron Shielding ◽  
Wear Rates ◽  
Uhmwpe Composites

This work reports on the simulated neutron and self-emitted gamma attenuation of ultra-high-molecular-weight polyethylene (UHMWPE) composites containing varying Sm2O3 contents in the range 0–50 wt.%, using a simulation code, namely MCNP-PHITS. The neutron energy investigated was 0.025 eV (thermal neutrons), and the gamma energies were 0.334, 0.712, and 0.737 MeV. The results indicated that the abilities to attenuate thermal neutrons and gamma rays were noticeably enhanced with the addition of Sm2O3, as seen by the increases in µm and µ, and the decrease in HVL. By comparing the simulated neutron-shielding results from this work with those from a commercial 5%-borated PE, the recommended Sm2O3 content that attenuated thermal neutrons with equal efficiency to the commercial product was 11–13 wt.%. Furthermore, to practically improve surface compatibility between Sm2O3 and the UHMWPE matrix and, subsequently, the overall wear/mechanical properties of the composites, a silane coupling agent (KBE903) was used to treat the surfaces of Sm2O3 particles prior to the preparation of the Sm2O3/UHMWPE composites. The experimental results showed that the treatment of Sm2O3 particles with 5–10 pph KBE903 led to greater enhancements in the wear resistance and mechanical properties of the 25 wt.% Sm2O3/UHMWPE composites, evidenced by lower specific wear rates and lower coefficients of friction, as well as higher tensile strength, elongation at break, and surface hardness, compared to those without surface treatment and those treated with 20 pph KBE903. In conclusion, the overall results suggested that the addition of Sm2O3 in the UHMWPE composites enhanced abilities to attenuate not only thermal neutrons but also gamma rays emitted after the neutron absorption by Sm, while the silane surface treatment of Sm2O3, using KBE903, considerably improved the processability, wear resistance, and strength of the composites.

The Functional TiO2-Biodegradable Plastic Composite Material Produced by HVOF Spraying Process

2007 ◽  
Vol 7 (11) ◽  
pp. 3830-3833 ◽  
Author(s):  
Hee-Seon Bang ◽  
Han-Sur Bang ◽  
Yoon-Ki Lee
Keyword(s):  
Photocatalytic Performance ◽  
Xrd Analysis ◽  
Gas Pressure ◽  
Photocatalytic Efficiency ◽  
Hvof Spraying ◽  
Photo Degradation ◽  
Fuel Gas ◽  
Plastic Composite ◽  
Polybutylene Succinate ◽  
Spraying Process

Photocatalytic TiO2 coatings on bio-degradable plastic(polybutylene succinate: PBS) were prepared by HVOF spraying using three kinds of agglomerated powders (P200: 200 nm, P30: 30 nm, P7: 7 nm). The microstructures of the coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of the coatings was evaluated by photo degradation of gaseous acetaldehyde. For both the HVOF sprayed P200 and P30 coatings, high anatase ratio of 100% was achieved, regardless of the fuel gas pressure. On the other hand, for the HVOF sprayed P7 coating, the anatase ratio decreased from 100% to 49.1% with increasing fuel gas pressure. This decrease may be attributed to the much higher susceptibility to heat of the 7 nm agglomerated powders than the 30 nm and 200 nm agglomerated powders. In terms of the photocatalytic efficiency, HVOF sprayed P200 and P30 coatings seemed to outperform the P7 coatings because of their higher anatase ratios. However, the HVOF sprayed P7 coatings did not show photocatalytic activity possibly because of the extremely small reaction surface area to the photo-catalytic activity and low anatase ratio. Therefore, the present study found that functional PBS plastic with photocatalytic performance could be produced by spraying of ceramics such as TiO2.

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