Journal ArticleDOI
Surface modification of plasma sprayed Al2O3–40 wt% TiO2 coatings by pulsed Nd:YAG laser melting
TLDR
In this article, a pulsed Nd:YAG laser melting with power densities of 640 and 800 kW/cm2 was used to minimize the surface porosity, micro-cracks, partially melted or unmelted regions, and achieving homogeneous microstructure.Abstract:
Plasma sprayed Al2O3–40 wt% TiO2 coatings were subjected to a pulsed Nd:YAG laser melting with power densities of 640 and 800 kW/cm2 in order to minimize the surface porosity, micro-cracks, partially melted or unmelted regions, and achieving homogeneous microstructure. As-sprayed and the laser melted surface microstructure, chemical composition, microhardness and roughness were characterized by using scanning electron microscopy-energy dispersive X-ray spectroscopy, X-ray diffraction, Vickers hardness and profilometer. Surface morphology of a laser melted coating showed that inhomogeneities are reduced, however, network of cracks were formed irrespective of power density. Columnar growth features were observed in laser melted regions when melted with 640 kW/cm2 while these were eliminated when melted with in 800 kW/cm2 power density. Predominant β-Al2TiO5 phase was observed upon both the laser melted coatings. With an increase of laser power density, laser melted coatings exhibited considerable increase in microhardness and decrease in surface roughness due to significant reduction in the surface defects.read more
Citations
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Journal ArticleDOI
Effect of plasma sprayed and laser re-melted Al2O3 coatings on hardness and wear properties of stainless steel
TL;DR: In this paper, the effect of the laser beam of various parameters on the microstructure, phase constituents, and mechanical and tribological properties of the ceramic coating was investigated by means of scanning electron microscopy, light microscopy and computer tomography, X-ray diffraction technique and nanoindentation tests.
Journal ArticleDOI
Structure and surface properties of Al2O3–TiO2 ceramic coated AZ31 magnesium alloy
TL;DR: In this article, a plasma spraying method is used to improve the poor corrosion resistance of AZ31 Mg alloy, which was applied on the surface of the alloy for tribological applications.
Journal ArticleDOI
Hot corrosion performance of LVOF sprayed Al 2 O 3 –40% TiO 2 coating on Superni 601 and Superco 605 superalloys at 800 and 900°C
N K Mishra,S B Mishra +1 more
TL;DR: Al2O3-40% TiO2 coating is applied on Superni 601 and Superco 605 superalloys by low-velocity oxy-fuel (LVOF) process as discussed by the authors.
Journal ArticleDOI
Comparative study on the tribological properties of laser post-treated and untreated AISI304 stainless steel matrix composite reinforced with hard ceramic particles (TiB2–TiN–SiC) and prepared by ex-situ P/M route
Debjit Misra,Sumit Barange,Hillol Joardar,Jitendra Kumar,Alok Kumar Das,Suman Mukhopadhyay,Satyajit Chatterjee +6 more
TL;DR: In this article, the authors highlight evaluation of suitable process parameters to result significantly higher hardness, fracture toughness and wear resistance in metal matrix composites developed with different proportions of reinforcements, namely, TiB2, TiN, and SiC in steel (AISI 304).
Journal ArticleDOI
Online monitoring of thermo cycles during laser remelting of flame sprayed chromia coating in pulsed mode and coating properties
Biswajit Das,Biswajit Das,Muvvala Gopinath,Muvvala Gopinath,Ashish Kumar Nath,Partha Pratim Bandyopadhyay +5 more
TL;DR: In this article, a fiber laser operating in pulsed mode was used to remelt flame sprayed chromia coating, and a columnar grain growth perpendicular to the coating surface was observed.
References
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Journal ArticleDOI
Ceramic materials for thermal barrier coatings
TL;DR: In this article, the basic properties of ceramic materials for thermal barrier coatings are summarized, showing that they are more resistant to oxidation, corrosion and wear, as well as being better thermal insulators.
Journal ArticleDOI
The quenching stress in thermally sprayed coatings
S. Kuroda,T.W. Clyne +1 more
TL;DR: In this article, a simple expression to evaluate the residual stress in a plasma-sprayed coating is given for the case where the coating thickness is much smaller than the substrate thickness.
Journal ArticleDOI
On the formation of thermally sprayed alumina coatings
TL;DR: In this paper, a model for the fomation of thermally sprayed alumina coatings is proposed and the spreading and crystallization of liquid droplets on impact with the substrate are analyzed and the thermal history of individual particles related to the kinetics of nucleation of γ-Al2O3 to other forms.
Journal ArticleDOI
Tribological properties of plasma sprayed alumina-titania coatings : Role and control of the microstructure
TL;DR: In this article, two different kinds of powder: one spray dried and one crushed and blended, were used to evaluate the friction behavior and wear resistance of the corresponding coatings in dry sliding conditions in two different configurations: block-on-ring (Amsler) and ball-ondisc.
Journal ArticleDOI
Evaluation of laser-glazed plasma-sprayed thermal barrier coatings under high temperature exposure to molten salts
C. Batista,A. Portinha,Ricardo M. Ribeiro,Vasco Teixeira,Carlos Augusto Fernandes de Oliveira +4 more
TL;DR: In this article, both as-sprayed and laser-glazed TBCs were exposed to hot corrosion in molten salts, and the results showed that the degradation in V 2 O 5 was accomplished by destabilization of yttria from the solid solution to form YVO 4 and therefore led to the disruptive transformation of the metastable tetragonal phase to the monoclinic phase.
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