Optimizating Spray Parameters of High Velocity Oxy Fuel (HVOF) for Cr3C2 - NiCr Coating

2019 ◽  
Vol 889 ◽  
pp. 168-176
Author(s):  
Văn Chien Dinh ◽  
Thanh Phu Nguyen ◽  
Thanh Hoa Doan ◽  
Van Khoa Bui
Keyword(s):  
High Performance ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Spray Parameters ◽  
Optimal Parameters ◽  
Coating Properties ◽  
Powder Feed Rate ◽  
Hvof Spray ◽  
High Performance Coating ◽  
40Cr Steel

Porosity, hardness, and adhesion mainly affect the performance of thermal spray coating and significantly depend on spray parameters. Therefore, determining value of the spray parameters and their effects on the coating properties are always taken into consideration. This paper studies optimization as well as evaluates influences of HVOF spray parameters which include powder feed rate (M), rotational speed of the details per minute (N) and step movement of the nozzle per revolution (S) to the adhesion, porosity, micro-hardness of Cr3C2 - 20(80Ni20Cr) coating on 40Cr steel shaft substrate. Taguchi experimental design L9 combined with analysis of variance (ANOVA) was used to determine optimum spray parameters and percentage of effect of each spray parameter on properties of the coating. From obtained results, the optimal spray parameters are m = 35 g.min-1, n = 130 rpm, S = 6 mm for the highest hardness coating of 658.2 HV; with m = 45g.min-1, n = 130rpm, S = 3 mm for the smallest porosity of 1.27%; with m = 35g.min-1, n = 130 rpm, S = 3 mm for the coating with a maximum adhesion of 44.07 MPa. The percent effects of the parameters m, n, S to adhesion, porosity and hardness were (2.8%, 33.6%, 63.6%), (0.1%, 1.3%, 98.6%), (32.7%, 43.3%, 24%), respectively. The percent effects of spray parameters on corresponding coating property allows adjustment of spray parameters to obtain the desired coating. Verified experiment results shows that the results are reliable. Taguchi method and ANOVA can find optimal parameters of the HVOF spray to acquire high-performance coating.

Optimization of Thermal Spray Parameters of NiAl/Cr2C3 Coating by Taguchi Method

2019 ◽  
Vol 295 ◽  
pp. 9-14 ◽  
Author(s):  
M. Tahari ◽  
B. Luo ◽  
J. Geng ◽  
D. Jing ◽  
M. Hatami
Keyword(s):  
Wear Resistance ◽  
Thermal Spray ◽  
Feed Rate ◽  
Spray Coating ◽  
Wear Test ◽  
Thermal Spray Coating ◽  
Spray Parameters ◽  
Spray Distance ◽  
Powder Feed Rate ◽  
Powder Feed

In this study the effect of thermal spray process on wear resistance of NiAl/Cr2C3 thermal spray coating has been investigated. For this purpose the NiAl power mixed with 10 %wt. Cr2C3 powder and milled for 1 hrs at argon atmosphere. The APS parameters such as voltage (V), current (A), spray distance (mm), powder feed rate (gr/min), were optimize using a response surface methodology. For investigation effect of spray parameters on quality of coatings, the porosity and wear resistance of coatings analyzed with SEM and pin on disk wear test. Results show that increase of voltage and current are more effective other parameters. Increasing of powder feed rate and spray distance raised porosity of coatings intensively.

Studying Adhesion between a 67Ni18Cr5Si4B Alloy Powder Coating Produced with the High Velocity Oxygen Fuel Thermal Spray Method HVOF and a Substrate Surface of a Worn C45 Steel Shaft

2020 ◽  
Vol 854 ◽  
pp. 117-125
Author(s):  
Văn Chien Dinh ◽  
Tuan Hai Nguyen ◽  
Khac Linh Nguyen
Keyword(s):  
Thermal Spray ◽  
Alloy Powder ◽  
Substrate Surface ◽  
Spray Coating ◽  
Powder Coating ◽  
Thermal Spray Coating ◽  
Modern Technology ◽  
Technological Parameters ◽  
Steel Shaft ◽  
Hvof Spray

Nowadays, thermal spray coatings are used to enhance mechanical properties of the material. One of the technologies used to produce thermal spray coating is HVOF spray technology. This is the most advanced and modern technology which has been widely used in the industry due to its flexibility and ability to create coatings with better adhesion in comparison with other thermal spray methods. This article presents some empirical findings from applying the 67Ni18Cr5Si4B alloy powder coating onto C 45 steel shaft by HVOF spray technology. It also analyzes the influence of some technological parameters on the adhesion of the coating. As a result, the parameters of HVOF spray technology are obtained suitable for recovering worn axis-sized workpieces.

Elasticity Characteristics of Plasma Spray Coatings

1996 ◽  
Author(s):  
L. Dekhtyar ◽  
A. Kleyman ◽  
S. Berman ◽  
V. Andreychuk
Keyword(s):  
Residual Stresses ◽  
Thermal Spray ◽  
Coating Thickness ◽  
Quantitative Methods ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Spray Parameters ◽  
Spray Coatings ◽  
Real Value ◽  
Elastic Characteristics

Abstract Future development of thermal spray processes and new composite materials raises an important problem concerning the transition from qualitative to quantitative methods of coatings evaluation. It is well known that thermal spray coating deposition in most cases is accompanied by the formation of temporal and residual stresses through the coating thickness. For proper evaluation of formed stressed state it is extremely important to know the real value of elastic characteristics in different layers of the coating. This problem has become more complicated taking into consideration the variety of materials, different spray parameters, number of coating layers and extreme service conditions. These values can be obtained only from experimentation. Elastic characteristics (EC) could be used in many calculations, such as durability, stiffness, fatigue, vibration and others. This paper describes new methods of experimental determination of elastic characteristics presumed as variable throughout the coating thickness. Influence of coating composition, particle size of initial powders, spray parameters, post-treatment and other factors on elastic modulusses were studied. Obtained experimental data for different materials supplement existing data and can be used for evaluation of residual stresses and other purposes.

Advanced Ceramic Tribological Layers by Thermal Spray Routes

2010 ◽  
Vol 66 ◽  
pp. 106-119 ◽  
Author(s):  
Rainer Gadow ◽  
Andreas Killinger ◽  
Andreas Rempp ◽  
Andrei Manzat
Keyword(s):  
Thermal Spray ◽  
High Performance ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Industrial Applications ◽  
General Interest ◽  
Special Focus ◽  
Functional Coatings ◽  
Spray Process ◽  
Combined Coatings

Protective and functional coatings featuring outstanding tribological performance are of general interest for all kinds of industrial applications i.e for high performance automotive and mechanical applications. Thermal spray coating technologies play a key role in fabricating hard layers based on ceramic, metal - ceramic and further multiphase materials. Additional functionality can be achieved by combining these coatings with polymer based top coats with low friction coefficient or anti adhesive behaviour. Combined coatings feature also designed thermophysical and electrophysical properties. Several case studies will be discussed, ranging from automotive applications to paper and printing industry. Thermally sprayed coatings were applied using APS, HVOF and the newly developed HVSFS processes (High Velocity Suspension Spraying) with a special focus on nanoceramic feedstocks. In some applications polymer top coats with dispersed solid phases are applied to enhance functional properties. Special aspects in manufacturing engineering are addressed with particular importance not only of the influence of spray process parameters on coating properties but also of spray torch kinematic and robot trajectories on hardness, residual stress distributions, dimensional tolerances and porosity distributions will be discussed.

Friction Behavior of HVOF Thermal Spray Coating of Micron Size WC-Co Powder

2007 ◽  
Vol 26-28 ◽  
pp. 1325-1328 ◽  
Author(s):  
Tong Yul Cho ◽  
Jae Hong Yoon ◽  
Kil Su Kim ◽  
Ki Oh Song ◽  
Yun Kon Joo ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Machine Component ◽  
Friction Behavior ◽  
Promising Candidate ◽  
Hvof Thermal Spray ◽  
Hvof Spray ◽  
Micron Size ◽  
Hard Chrome

High velocity oxy-fuel (HVOF) spray coating of WC base cermet has been studied as a promising candidate in some hard coating area for a replacement of the long traditional electrolytic hard chrome (EHC) plating, which has been raising public health and environmental problems. Micron size WC-Co (mWC-Co) has been coated on Inconel 718 substrate by HVOF thermal spray coating process. Surface properties of coating layer and friction behavior have been investigated for durability improvement coating on the sliding machine component surface.

scholarly journals Microstructure and Sliding Wear Resistance of Plasma Sprayed Al2O3-Cr2O3-TiO2 Ternary Coatings from Blends of Single Oxides

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 42 ◽  
Author(s):  
Maximilian Grimm ◽  
Susan Conze ◽  
Lutz-Michael Berger ◽  
Gerd Paczkowski ◽  
Thomas Lindner ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Sliding Wear ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Corrosion And Wear ◽  
Atmospheric Plasma ◽  
Spray Parameters ◽  
Oxide Materials ◽  
Spray Process ◽  
Plasma Sprayed

Al2O3, Cr2O3, and TiO2 are most commonly used oxide materials for thermal spray coating solutions. Each oxide shows unique properties comprising behavior in the spray process, hardness, corrosion, and wear resistance. In order to exploit the different advantages, binary compositions are often used, while ternary compositions are not studied yet. Atmospheric plasma spraying (APS) of ternary compositions in the Al2O3-Cr2O3-TiO2 system was studied using blends of plain powders with different ratios and identical spray parameters. Coatings from the plain oxides were studied for comparison. For these powder blends, different deposition rates were observed. The microstructure, roughness, porosity, hardness, and wear resistance were investigated. The formation of the splats from particles of each oxide occurs separately, without interaction between the particles. The exception are the chromium oxide splats, which contained some amounts of titanium. The predominant oxide present in each blend has a decisive influence on the properties of the coatings. While TiOx causes a low coating porosity, the wear resistance can be increased by adding Cr2O3.

Effects of corrosion on a steel bowstring bridge in marine environment: A case-study of assessment and retrofit

2021 ◽  
Vol 16 (4) ◽  
pp. 121-137
Author(s):  
Michele Fabio Granata
Keyword(s):  
Corrosion Protection ◽  
Marine Environment ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
In Situ Tests ◽  
Limit States ◽  
Intervention Measures ◽  
Near Future

The case-study of a steel bowstring bridge set in a marine environment and highly damaged by corrosion is presented. The bridge was built in 2004 and was repainted for corrosion protection in 2010. Despite the recent construction and the maintenance interventions, many structural elements like hangers are highly damaged by corrosion with decreasing performance in terms of serviceability and ultimate limit states. A deep investigation was carried out in order to assess the bridge and to establish the necessary retrofit actions to be carried out in the near future. In-situ tests reveal the reduced performance of the original steel in terms of strength and corrosion protection, together with the inefficiency of the successive maintenance interventions. The paper presents assessment of the bridge and retrofit measures, including replacement of the hangers and galvanization through thermal spray coating technology, in order to increase its service life. The results of the investigations and the intervention measures are outlined and discussed.

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