Crack Resistance of Weld Seals, Hardening Methods and Composite Tools Quality

2014 ◽  
Vol 682 ◽  
pp. 431-437 ◽  
Author(s):  
V.A. Petrova ◽  
A.A. Bakanov ◽  
A.V. Walter
Keyword(s):  
Crack Resistance ◽  
Interfacial Adhesion ◽  
Thermal Spraying ◽  
Substrate Material ◽  
Metallographic Analysis ◽  
Alternating Projections ◽  
Optical Profilometry ◽  
Surface Optical ◽  
End Products ◽  
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.

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.

Improvement of Solution Type Plasma Spraying Process

2005 ◽  
Vol 502 ◽  
pp. 505-510 ◽  
Author(s):  
Masami Futamata ◽  
Xiaohui Gai ◽  
Toyokazu Mizumoto ◽  
Kimio Nakanishi
Keyword(s):  
Mechanical Properties ◽  
Plasma Spraying ◽  
Hollow Cathode ◽  
Thermal History ◽  
Thermal Spraying ◽  
Physical And Mechanical Properties ◽  
Good Reproducibility ◽  
Solution Type ◽  
Plasma Spraying Process ◽  
Spraying Process

To fabricate thermal spraying coatings with good reproducibility, it is necessary to improve the process of the equalization of both thermal history and impacting behavior of the particles. In this study, the characteristics of the solution type plasma spraying using the hollow-cathode type torch are investigated. The physical and mechanical properties that are different from usual thermal spraying coatings are described. By using solutions including metal ingredients in a state of ion, colloid or sol, thinner coating that cannot be made by conventional plasma spraying methods is formed on various substrates. The coatings are uniform in appearance.

Effects of Gun Nozzle Geometry on High Velocity Oxygen-Fuel (HVOF) Thermal Spraying Process

1998 ◽  
Author(s):  
K. Sakaki ◽  
Y. Shimizu ◽  
Y. Gouda ◽  
A. Devasenapathi
Keyword(s):  
Numerical Simulation ◽  
Experimental Studies ◽  
Thermal Spraying ◽  
Deposition Efficiency ◽  
Divergence Angle ◽  
Nozzle Geometry ◽  
Oxide Content ◽  
Hvof Thermal Spraying ◽  
Throat Diameter ◽  
Spraying Process

Abstract Effect of nozzle geometry (such as throat diameter of a barrel nozzle, exit diameter and exit divergence angle of a divergent nozzle) on HVOF thermal spraying process (thermodynamical behavior of combustion gas and spray particles) was investigated by numerical simulation and experiments with Jet KoteTM II system. The process changes inside the nozzle as obtained by numerical simulation studies were related to the coating properties. A NiCrAIY alloy powder was used for the experimental studies. While the throat diameter of the barrel nozzle was found to have only a slight effect on the microstructure, hardness, oxygen content and deposition efficiency of the coatings, the change in divergent section length (rather than exit diameter and exit divergence angle) had a significant effect. With increase in divergent section length of the nozzle, the amount of oxide content of the NiCrAIY coatings decreased and the deposition efficiency increased significantly. Also, with increase in the exit diameter of the divergent nozzle, the gas temperature and the degree of melting of the particle decreased. On the other hand the calculated particle velocity showed a slight increase while the gas velocity increased significantly.

Application of Metallographic Analysis Techniques for Detection and Identification of Spray Paint Defects

2017 ◽  
Vol 270 ◽  
pp. 118-123
Author(s):  
Michaela Remešová ◽  
Lenka Klakurková ◽  
Ivana Ročňáková ◽  
Ladislav Čelko ◽  
Lucie Páleníková ◽  
...  
Keyword(s):  
Substrate Material ◽  
Consumer Electronics ◽  
Metallographic Analysis ◽  
Surface Appearance ◽  
X Ray ◽  
Detection And Identification ◽  
Digital Microscope ◽  
Negative Effect ◽  
Paint Films

The paper is focused on the metallographic analysis of spray paint films with defects. The painting has two important roles. Firstly, it protects the substrate material (ferrous, nonferrous and plastic) and secondly, it improves the appearance of the surface. Appearance and quality of painting film play an important role in the industry (automotive, aerospace, consumer electronics, etc.). Defects of spray painting film, which have a negative effect on the appearance of the product, can be detected and further analysed by common methods used in metallography. Such methods are very effective tool for revealing the cause of defects and their elimination within the technological process (degreasing, cleaning, pickling, drying, technological discipline, etc.). In this paper, defects were characterized by high-resolution digital microscope (LM) and scanning electron microscope (SEM) equipped with energy dispersive X-ray analyser (EDX).

scholarly journals NiTi Splat Features during Vacuum Thermal Spraying onto Several Substrates

2013 ◽  
Vol 738-739 ◽  
pp. 357-361
Author(s):  
Nuria Cinca ◽  
Antonio Isalgué ◽  
Javier Fernández ◽  
S. Sampath
Keyword(s):  
Stainless Steel ◽  
Niti Alloy ◽  
Thermal Spraying ◽  
Thermal Effusivity ◽  
Substrate Material ◽  
Splat Morphology ◽  
Vacuum Plasma Spraying ◽  
Vacuum Plasma ◽  
Aluminium Copper ◽  
Steel Substrates

Vacuum Plasma Spraying has been used to produce coatings onto steel substrates. This work deals with the study of splat morphology of the NiTi alloy sprayed by VPS onto different substrates (aluminium, copper, stainless steel, glass and alumina). All the previous characteristics are discussed in terms of wettability and thermal conductivities regarding the rapid cooling involved in the process. Although identical conditions were used during thermal spraying, a wide variety of splat formations were observed; commonly, slushy or splash/disc splats are formed depending on whether the particles have partially or fully melted. The thermal effusivity of the substrate material, which is a measure of its ability to exchange thermal energy with its surroundings, seems to play an important role promoting more or less spreading. The higher the thermal effusivity is, the more rapidly the splats are cooled, thus starting the solidification before they come to rest and, changing their morphology.

Influence of Substrate on Cracking of Vapour-Deposited Thin Films Due to Residual Stresses

1989 ◽  
Vol 153 ◽  
Author(s):  
Robert M. Fisher ◽  
J.Z. Duan
Keyword(s):  
Residual Stresses ◽  
Interfacial Adhesion ◽  
Film Formation ◽  
Critical Value ◽  
Substrate Material ◽  
X Ray Diffraction ◽  
Polymer Substrates ◽  
X Ray ◽  
Influence Of Substrate

AbstractThe influence of the substrate material on the column and grain microstructure, the residual stresses, crack patterns and delamination of Cr films has been investigated using TEM, SEM, and X-ray diffraction. The inter-influence of these factors which determine the long term reliability of microelectronics is discussed. When interfacial adhesion is very low, as may be the case with some polymer substrates, cracking occurs discontinuously during film formation each time the stress exceeds the critical value for fracture.

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