Influence of Surface Condition on the Bonding Strength of Thermal Sprayed Coatings

1997 ◽  
Author(s):  
V.Yu. Ulianitsky ◽  
J.A. Nikolaev ◽  
T.P. Gavrilenko ◽  
M.C. Kim ◽  
J.W. Hong
Keyword(s):  
Bonding Strength ◽  
Substrate Surface ◽  
Surface Condition ◽  
Surface Preparation ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Substrate Material ◽  
Detonation Spraying ◽  
Wide Scale ◽  
Detonation Gun

Abstract The role of surface roughness in coating adhesion mechanism is studying for detonation spraying. Roughness was produced by conventional grit blasting, D-gun blasting and was formed as a result of spraying of high-adhesive thin layer of detonation coating. Cermet and alloy powders were sprayed by detonation gun Ob. The coating bonding strength measurements show the WC+25Co adhesion to be above 200 MPa independently of a substrate surface preparation. Contrary, NiCrSiB coatings are very sensitive to surface conditions their adhesion varies from 180 MPa to zero. As-sprayed alloy particles fail in adherence because of insufficient energy to fuse substrate material at a flat surface. Only developed (wide scale) roughness may be fused partially by these particles for their bonding to the substrate. Otherwise, high heated cermet particles do not need special surface preparation (except cleaning) for fusion of substrate material to provide high bonding with it. The wide scale and ball shape roughness, which is similar to the self-reproduced coating roughness, provides the best conditions for the coating bonding and it is recommended as the purpose of surface treatment before thermal spray coating.

scholarly journals PELAPISAN PERMUKAAN DALAM NOSEL ROKET RKX100 DENGAN Cr2C3-NiCr HVOF: OPTIMASI KEKUATAN LEKAT MELALUI VARIASI KEKASARAN PERMUKAAN

2010 ◽  
Vol 2 (1) ◽  
Author(s):  
Bondan T.Sofyan ◽  
Yus Prasetyo ◽  
Sayid Ardiansyah ◽  
Yus Prasetyo ◽  
Edy Sofyan
Keyword(s):  
Surface Roughness ◽  
Thermal Spray ◽  
Bonding Strength ◽  
Spray Coating ◽  
Hardness Measurement ◽  
Thermal Spray Coating ◽  
Optical Microscope ◽  
Mechanical Interlocking ◽  
Micro Hardness ◽  
Scanning Electron

Nozzle of RKX100 rocket contributes 30 percent to the total weight of the structure, so that allowing further research on weight reduction. An alternative for this is by substitution of massive graphite, which is currently used as thermal protector in the nozzle, with thin layer of HVOF (High Velocity Oxy-Fuel) thermal spray layer. A series of study on the characteristics of various type of HVOF coating material have been being conducted. This paper presented the investigation on the HVOF Cr2C3-NiCr thermal spray coating, in particular, the optimization of bonding strength by varying surface roughness of substrates. Characterization included bonding strength test, micro hardness measurement and micro structural observation with optical microscope and scanning electron micriscope (SEM). The results showed that grit blasting pressure increass the surface roughness from 4,54 um to 5.72 um at the pressure of 6 bar. Average micro hardness of the coating was 631 VHN 300. Coating applied to the surface with rougness of 5.42 um possessed the highest bonding strength, 44 MPa. Microstructural observation by using optical microscope and scanning electron microscope (SEM) confirmed dense lamellae structure with variable composition. High coating adherence was found to be due to mechanical interlocking.

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.

Atomic Force Microscopy Study on WC 14Co and WC 14Co+CNT Coated Surfaces

2015 ◽  
Vol 766-767 ◽  
pp. 573-578
Author(s):  
K.N. Balan
Keyword(s):  
Atomic Force Microscopy ◽  
Surface Finish ◽  
Spray Coating ◽  
Surface Characteristics ◽  
Microscopy Study ◽  
Thermal Spray Coating ◽  
Force Microscopy ◽  
Coating Technique ◽  
Atomic Force ◽  
Detonation Gun

There are several methods to improve surface characteristics. Detonation Gun coating (D-Spray) is one of the popular method in thermal spray coating technique. Generally, to enhance the surface properties like wear and corrosion resistance, microhardness, surface finish etc.. D-Spray process was preferred. In this present study, the property of surface finish was considered for the coating powders of WC 14Co and WC 14Co+CNT. The Powder WC 14Co+CNT was prepared in a systematic way and coating process was carried out by using detonation gun coating technique. Scanning Electron Microscopy (SEM) had been done on the powders of with and without CNT and Atomic force Microscopy (AFM) analysis on the surface was done for various places on the surface. A significant effect on the surface finish was exhibited.

Thermal Spray Methods and Splat Formation

2018 ◽  
pp. 1-24
Author(s):  
Wei Xie
Keyword(s):  
Thermal Spray ◽  
Substrate Surface ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Splat Formation ◽  
Wetting Ability ◽  
Large Structures ◽  
Coating Morphology ◽  
Spray Processing ◽  
The Individual

This chapter describes how surface coatings play a significant role in manufacturing industries due to improvements in the properties of the engineering components that lead to longer service life and reliability. Thermal spray is well suited for large structures and can be easily repaired. Previous publications concerning the principle of thermal spray processing; powder and their fabrication methods; the effect of substrate surface conditions on splat formation and morphologies; the effect of process parameters on splat formation and morphology; and thermal spray coating morphology are reviewed. Also described in detail is physical behaviour, such as thermal conductivity and wetting ability at impact between the thermal spray particle and the substrate, influences the individual splat geometry and coating build-up and, consequently, the coating properties.

A Study on Various Process Parameters Involved in Detonation Gun Coating Technique

2013 ◽  
Vol 651 ◽  
pp. 378-383 ◽  
Author(s):  
K.N. Balan ◽  
B.R. Ramesh Bapu ◽  
Rituraj Roy
Keyword(s):  
Taguchi Method ◽  
Thermal Spray ◽  
Process Parameters ◽  
Surface Property ◽  
Spray Coating ◽  
Surface Characteristics ◽  
Thermal Spray Coating ◽  
Coating Technique ◽  
The World ◽  
Detonation Gun

Various researches are being conducted in many parts of the world, to improve the surface characteristics of the materials. Thermal spray coating is one of the methods used for enhancing the surface property of the material. Our experiment deals with the study of detonation gun spray coating of WC-12Co, WC-10Co-4Cr and Cr2C3-25NiCr powders. The coating was done on SS316 substrate by varying the process parameters. The process parameters were optimized using Taguchi method to obtain greater hardness.

Interfacial Adhesion between Thermal Spray Coating and Substrate Achieved by Ultrasonic Finishing

2014 ◽  
Vol 682 ◽  
pp. 459-463 ◽  
Author(s):  
Zhanna G. Kovalevskaya ◽  
Vasilii A. Klimenov ◽  
Konstantin V. Zaitsev
Keyword(s):  
Interfacial Adhesion ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Substrate Material ◽  
Metallographic Analysis ◽  
Alternating Projections ◽  
Optical Profilometry ◽  
Surface Optical ◽  
Spraying Process

The paper presents a pretreatment of the substrate material prior to the thermal spraying process. The ultrasonic finishing method allowed creation of a rolling topography comprising alternating projections and cavities, compressive stress, and increase of the number of defects on the surface. Optical profilometry and metallographic analysis allowed detecting of adhesion zones which form a strong physicochemical bond at the interface between the coating and the substrate material. This interfacial adhesion should provide a firm adhesion strength in end products.

Experimental Approach to Adhesion between an Alumina Plasma-Sprayed Coating and Polymeric Substrate

1996 ◽  
Author(s):  
P. Lucchese ◽  
R. Jeandin ◽  
G. Surdon ◽  
A. Delavernme
Keyword(s):  
Bond Coat ◽  
Surface Preparation ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Fiber Layer ◽  
Bond Coats ◽  
Reinforced Polymer ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Thermally Sprayed

Abstract Thermal spray coating of fiber reinforced polymer (FRP) components has a high development potential to improve their wear, erosion and corrosion resistance. This paper deals with the optimization of plasma spraying conditions of alumina onto a FRP substrate, including the study of surface preparation. The so-called "Atmosphere and Temperature Controlled Process (ATC, patented by CEA)" was used to maintain the substrate temperature at a rather low level, i.e. near room temperature. Various surface preparation processes such as grit blasting, cleaning using the plasma torch and pre-coating with an intermediate bond coat were tested. The latter was shown to improve adhesion between the coating and the substrate significantly, when using 2 types of bond coats. One consisted of an additionnal fiber layer directly stuck to the substrate, the other of an intermediate thermally-sprayed PEEK layer. Results of adhesion tests were discussed in the light of interface characterization. Using a PEEK bond coat led to an adhesion strength between alumina and the substrate 3 times better than that for the material without any bond coat.

Prediction of Best Combination of Process Parameters for Detonation Gun Coating Process through Taguchi Technique

2014 ◽  
Vol 984-985 ◽  
pp. 520-525
Author(s):  
K.N. Balan ◽  
S. Manimaran ◽  
A. Johnrajan ◽  
E.V.V. Ramanamoorthy
Keyword(s):  
Thermal Spray ◽  
Process Parameters ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Major Effect ◽  
Aviation Industry ◽  
Optimum Process ◽  
Coating Process ◽  
Marine Industry ◽  
Detonation Gun

Detonation gun spray coating method (D-Spray) [1] is one of the effective method of thermal spray coating process. The surface of material or substrate will be enhanced by deposition of coating powders such as metal oxides and ceramics like aluminium oxides, tungsten carbide ,nickel chromium etc by D-spray method that prevents the metal from corrosion and to increase the wear resistance. This coating process had wide applications in different engineering sectors such as aviation industry, marine industry, biomedical industry etc., In this Experimental study the Process parameter optimization of D-spray coating process which is one of the Thermal spray Coating process was done by Taguchi method, [3] in order to find the best processing conditions and to get higher quality of coating. [6] Microhardness was estimated for various combinations of parameters and the optimum process parameters were obtained. Best combination of process parameters has been predicted which results that the thickness of the coating has got a major effect.

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