The Ultimate Spray Booth

1997 ◽  
Author(s):  
L. Pejryd ◽  
J. Wigren ◽  
N. Hanner
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Design Element ◽  
Production Flow ◽  
Statistical Process ◽  
Spray Coatings ◽  
Spray Process ◽  
Spray Booth ◽  
On Line

Abstract Reproducibility is a current challenge for the thermal spray industry. Reproducibility associated problems represent a large cost every year not only in terms of rejections and rework, but also in costs for destructive testing and decreased production flow. Thermal spray coatings are moving in the direction of being considered only as a "band aid" to becoming a design element. One of the prerequisites for such a development is an increase in reproducibility for thermal spray coatings. The purpose of this paper is to outline a vision aiming in the direction of a future "ultimate spray booth", where thermal spraying is as reproducible and reliable as machining, grinding or other production processes. A way to increase reproducibility and reliability in the future spray shop involves utilising major parts of IT - technology. This also includes active co-operation design-production in the pre-spray process. This paper will deal with areas such as: operation drawings and lists through multimedia techniques, education programs for operators and designers through multimedia techniques, CAD/CAM, Off-line programming and simulation, On-line diagnostics of flame (particle diagnostics) and coating (temperature & Acoustic emission measurements), on-line Statistical Process Control and Knowledge Based System techniques.

Comprehensive Methods for Studying Microinhomogeneity in Thermal Spray Coatings with Amorphous-Crystalline Structure

1998 ◽  
Author(s):  
G. Grigorenko ◽  
A. Borisova
Keyword(s):  
Thermal Spray ◽  
Crystalline Structure ◽  
Structural Phase ◽  
Thermal Spraying ◽  
Integrated Approach ◽  
Thermal Spray Coatings ◽  
Chemical Heterogeneity ◽  
New Approach ◽  
X Ray ◽  
Spray Coatings

Abstract An integrated approach was developed for investigation of thermal spray coatings with the amorphous-crystalline structure. The new approach combines methods of metallography, differential thermal and X-ray phase analysis, scanning electron microscopy and X-ray microanalysis. This makes it possible to reveal structural, phase and chemical heterogeneity, determine the degree of amorphization of coatings, temperature and heat of crystallization of the amorphous phase during heating. The new integrated approach was used to study amorphous-crystalline coatings of the Ni-P, Fe-Ni-B and Fe-B systems produced by thermal spraying.

Image-Based Modeling for Assessing Thermal Conductivity of Thermal Spray Coatings at Ambient and High Temperature

2006 ◽  
Author(s):  
Y. Tan ◽  
A. Sharma ◽  
J. P. Longtin ◽  
S. Sampath ◽  
H. Wang
Keyword(s):  
Thermal Conductivity ◽  
High Temperature ◽  
Thermal Spray ◽  
Process Parameters ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Analysis Model ◽  
Element Analysis ◽  
Spray Coatings ◽  
Coating Microstructure

Thermal spray coatings are used extensively for protection of engineering components and structures in a variety of applications. Due to the nature of thermal spraying process, the coating thermal, mechanical, and electrical properties depend strongly on the coating microstructure, which consists of many individual splats, interfaces between the splats, defects and voids. The coating microstructure, in turn, is determined by the thermal spray process parameters. In order to relate coating process parameters to the final coating performance, then, it is desirable to relate coating microstructure to coating properties. In this work, thermal conductivity is used as the physical parameter of interest. Thermal conductivity of thermal spray coatings is studied by using an image analysis-based approach of typical coating cross sections. Three coating systems, yttria stabilized zirconia (YSZ), molybdenum, and Ni-5wt.%Al are explored in this work. For each material, thermal conductivity is simulated by using a microstructure image-based finite element analysis model. The model is then applied to high temperature conditions (up to 1200 °C) with a hot stage-equipped scanning electron microscope imaging technique to assess thermal conductivity at high temperatures. The coating thermal conductivity of metallic coatings is also experimentally measured by using a high-temperature laser flash technique.

Methods of Determination and Control of Residual Stresses in Plasma Spray Coatings

1997 ◽  
Author(s):  
L. Dekhtyar ◽  
A. Kleyman ◽  
V. Andreychuk ◽  
S. Berman
Keyword(s):  
Residual Stresses ◽  
Thermal Spray ◽  
Plasma Spray ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Coating Deposition ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
And Control ◽  
Elastic Characteristics

Abstract Residual stresses exert profound influence on the longevity of parts with thermal spray coatings. The distribution and value of the residual stresses depend on method of coating deposition, composition of the applied material, parameters of thermal spraying and methods of post-treatment. Therefore, the study of the influence of the various technological factors on the residual stresses in the plasma spray coatings is very important. Due to heterogeneity of the coating, residual stresses can be determined only by the experimentation by using new methods which take into consideration real values of elastic characteristics and density of elementary layers. Methods and formulas for the calculations of the residual stresses in coatings deposited on bars, rings, discs, cylinders are presented. Experimental results for the various thermal spray coatings are also shown. These results can be used for the optimization of coating deposition and would supplement the existing database.

Principles and Applications of Thermal Spray Coatings

2021 ◽  
pp. 31-70
Author(s):  
John Henao ◽  
Carlos A. Poblano-Salas ◽  
Fabio Vargas ◽  
Astrid L. Giraldo-Betancur ◽  
Jorge Corona-Castuera ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Industrial Applications ◽  
Thermal Spray Coatings ◽  
Flame Spray ◽  
Spray Coatings ◽  
Thermal Barriers ◽  
Energy Conversion Devices ◽  
Thermally Sprayed ◽  
Sprayed Coatings

The goal of the chapter is to address the fundamental theory of thermal spraying and its modern industrial applications, in particular, those involving flame spray, HVOF, plasma spray, and cold spray processes. During the last 30 years, thousands of manuscripts and various book chapters have been published in the field of thermal spray, displaying the evolution of thermally sprayed coatings in many industrial applications. Thermal spray coatings are currently interesting for different modern applications including prosthesis, thermal barriers, electrochemical catalysis, electrochemical energy conversion devices, biofouling, and self-repairing surfaces. The chapter will explain the fundamental principles of the aforementioned thermal spraying processes and discuss the effect of different controlling parameters on the final properties of the produced coatings. This chapter will also explore current and future industrial applications of thermal spray coatings.

USE OF IBA TECHNIQUES TO CHARACTERIZE HIGH VELOCITY THERMAL SPRAY COATINGS

2001 ◽  
Vol 15 (28n29) ◽  
pp. 1428-1436 ◽  
Author(s):  
W. TROMPETTER ◽  
A. MARKWITZ ◽  
M. HYLAND
Keyword(s):  
Thermal Spray ◽  
High Velocity ◽  
Sliding Wear ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Spray Coatings ◽  
The Past ◽  
Composition And Structure ◽  
Wide Range ◽  
Sprayed Coating

Spray coatings are being used in an increasingly wide range of industries to improve the abrasive, erosive and sliding wear of machine components. Over the past decade industries have moved to the application of supersonic high velocity thermal spray techniques. These coating techniques produce superior coating quality in comparison to other traditional techniques such as plasma spraying. To date the knowledge of the bonding processes and the structure of the particles within thermal spray coatings is very subjective. The aim of this research is to improve our understanding of these materials through the use of IBA techniques in conjunction with other materials analysis techniques. Samples were prepared by spraying a widely used commercial NiCr powder onto substrates using a HVAF (high velocity air fuel) thermal spraying technique. Detailed analysis of the composition and structure of the power particles revealed two distinct types of particles. The majority was NiCr particles with a significant minority of particles composing of SiO 2/ CrO 3. When the particles were investigated both as raw powder and in the sprayed coating, it was surprising to find that the composition of the coating meterial remained unchanged during the coating process despite the high velocity application.

Microprobe X-ray studies of thermal spray coatings

2010 ◽  
Vol 1 (SRMS-7) ◽  
Author(s):  
P. D. Quinn ◽  
J. F. W. Mosselmans ◽  
D. G. McCartney ◽  
D. Zhang
Keyword(s):  
Thermal Spray ◽  
Protective Coatings ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Extreme Conditions ◽  
Structural Variations ◽  
Coating Performance ◽  
X Ray ◽  
Spray Coatings

Thermal spraying is emerging as the leading route for the deposition of protective coatings onto engineering components to improve operation under extreme conditions of temperature, wear or corrosion. Detailed microstructural assessment is a key element in improving coating performance, and this study demonstrates the application of microfocus X-ray techniques to the determination of elemental and structural variations in the coatings.

In Situ Temperature Measurement Using Embedded Micro-Thermocouples in Vacuum Plasma Sprayed Multi-Layered Structures

1998 ◽  
Author(s):  
C. Verdy ◽  
B. Serio ◽  
C. Coddet
Keyword(s):  
Thermal Spray ◽  
Thermal Spray Coatings ◽  
Spray Coatings ◽  
Spray Process ◽  
Vacuum Plasma ◽  
Copper Coatings ◽  
Plasma Sprayed ◽  
Spraying Process ◽  
Infrared Pyrometer

Abstract The integration of thermocouples into thermal spray deposits and especially into vacuum thermal spray coatings could provide temperature monitoring between the substrate and the coating or between two different coatings during the spray process and later during post treatments and service life. Thermocouples of 251µm in diameter were made using Chromel® and Alumel® wires. Electrical insulation was obtained using a ceramic cement. Astroloy and Copper coatings were successfully sprayed over these sensors and the temperature given by an embedded thermocouple was compared to the response of an infrared pyrometer during the spraying process.

Characterization of Thermal Spray Coatings Used for Dimensional Restoration

2000 ◽  
Author(s):  
R.T.R. McGrann ◽  
J. Kim ◽  
J.R. Shadley ◽  
E.F. Rybicki ◽  
N.-G. Ingesten
Keyword(s):  
Residual Stress ◽  
Bond Strength ◽  
Thermal Spray ◽  
Thermal Spray Coatings ◽  
Tensile Bond Strength ◽  
Spray Angle ◽  
Metallographic Examination ◽  
Substrate Interface ◽  
Spray Coatings ◽  
Spray Process

Abstract Thick thermal spray coatings are used to repair worn parts during aircraft overhaul. The thermal spray coating is used to restore a part to its original dimensions. Characteristics of the as-applied coating that affect the performance of thermal sprayed parts are the residual stress in the coating, the tensile bond strength, the amount of porosity, oxides and impurities near the coating/substrate interface, and the hardness of the coating. An understanding of the relation of these coating characteristics to process variables such as the material used for the coating, spray process, spray angle, and thickness of the applied material is needed. In this paper, four thermal spray coatings, Ni5Al, Ni5Al-atomized, (NiCr)6Al, and Inco 718, on a substrate of Hastelloy X are investigated. These materials are applied using two different thermal spray application processes: plasma spray and High Velocity Oxy-Fuel (HVOF). Spray angles of 90° and 45° are used during spraying. The nominal thickness of the applied coatings ranges from 0.4 mm to 1.8 mm. The thermal spray coatings are evaluated in four types of tests. Residual stresses in the coatings and substrate are evaluated using the modified layer removal method. A tensile bond strength test is performed. Metallographic examination is used to determine the porosity and content of oxides and bond zone impurities (percent) of the applied materials. In addition, the hardness of the coating is measured. For the materials and conditions investigated, it is found that residual stress varies with each of the four process parameters. The bond strength for plasma sprayed coatings is related to the type of material and possibly to the coating thickness. The percent porosity varies with coating material, but, for Ni5Al, it does not depend on application process. Oxide content, as a percentage, varies with material and process, but not with spray angle and thickness. The percentage of impurities near the coating/substrate interface varies with process and, for the specimens that were coated using the HVOF process, with thickness. The hardness of the coating was found to vary with material and spray process. For three of the four coatings, hardness increases with thickness but, for Inco 718, hardness decreases as thickness increases.

Prediction of Residual Stress and Damage in Thermal Spray Coatings Using Hybrid Computational Approach

2018 ◽  
Author(s):  
Abba A. Abubakar ◽  
Abul Fazal M. Arif ◽  
Khaled S. Al-Athel ◽  
S. Sohail Akhtar
Keyword(s):  
Residual Stress ◽  
Thermal Spray ◽  
Point Cloud ◽  
Hybrid Approach ◽  
Computational Approach ◽  
Thermal Spray Coatings ◽  
Element Analysis ◽  
Influence Of Process Parameters ◽  
Spray Coatings ◽  
Spray Process

Due to the multilayered pattern of coating deposition, numerical prediction of residual stress and damage in thermal spray coatings (TSCs) has been challenging. Several numerical approaches previously used failed to capture essential aspects such as deposition stress build-up, presence of heterogeneities, and influence of process parameters. In the present study, a hybrid computational approach which combines “point cloud” (PC) and finite elements (FE) has been used to model the spray process as well as the evolution of residual stress and damage. Smooth particle hydrodynamics (SPH) is used to model multiple droplets deposition and associated deformation on PC. Then, several recent algorithms (for point cloud processing) are used to convert the deformed droplets (in form of PC) into FE domains (i.e. splats). The FE mesh of deposited splats is used for thermo-mechanical finite element analysis where the evolution of temperature, residual stress and damage is predicted on simulated coating microstructure. By comparing our numerical results with that of previous works, the hybrid approach has been found to be a viable tool for quantitative assessment of residual stresses and failure in TSCs.

Thermal Spraying of Wear and Corrosion Resistant Surfaces

2008 ◽  
Vol 384 ◽  
pp. 75-98 ◽  
Author(s):  
Bernhard Wielage ◽  
Thomas Lampke ◽  
Thomas Grund
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Base Material ◽  
Thermal Spray Coatings ◽  
Selective Coating ◽  
Spray Coatings ◽  
Wear And Corrosion ◽  
Parameter Field ◽  
Thermal Spray Processes ◽  
Sprayed Coatings

Thermal spraying is one of the most variable and diverse surface coating techniques concerning materials to be processed as well as possible geometries to be coated. The group of thermal spray processes covers a large parameter field to combine nearly each coating with each base material. Thermally sprayed coatings can be applied very evenly and therefore allow to be applied on final-shaped components. Otherwise, if further treatment or finishing is necessary, thermal spray coatings can be processed by grinding or even milling. Masking during the coating process permits the selective coating of specific surface parts or the application of required geometrically structures, e. q. conductor structures. The main application field of thermal spray coatings is the (combined) wear and corrosion protection of selected component parts.

Sign in / Sign up

Export Citation Format

Share Document