scholarly journals FORMATION OF FUNCTIONAL PLASMA SPRAYED COATINGS WITH COMPLEX OF IMPROVED PHYSICAL, MECHANICAL AND OPERATIONAL PROPERTIES

Author(s):  
А. Karpechenko ◽  
M. Bobrov

The possibility of increasing the complex of physical, mechanical and operational properties of plasma sprayed coatings from powders of the PG-19M-01 and PRH18N9 grades due to the electric pulse effect on the heterophase high-temperature flow during spraying and next surface plastic deformation of the deposited coatings by shot blasting has been investigated. It is shown that shot blasting provides the formation of a hardening layer with a thickness of up to 180...200 μm, while the maximum level of microhardness is observed at a depth of about 60 μm. The microhardness of the coating from PG-19M-01 powder at the point of maximum hardening increases by 35%; steel coatings from PR-H18N9 powder – by 48% compared to the state after spraying. Experimental studies of the effect of this treatment on the bond strength and wear resistance of the obtained coatings have been carried out. It is shown that after shot-blasting the bond strength of the coatings decreases by 10...15%, and the wear resistance increases by 32...38%.

Author(s):  
J. Wilden ◽  
M. Wank ◽  
H.D. Steffens ◽  
M. Brune

Abstract YPSZ-thermal barrier coatings are widely used in industries. Nevertheies there is secure interest in TBC's for higher temperature application. Ceria or miao-alloyed ceria shows the potential to be used at higher temperatures than YPSZ. Ceria and YPSZ-Ceria-multi-layer thermal barrier coatings were produced by plasma and high velocity oxygen flame (HVOF) spraying. Bond strength and thermal shock behaviour were tested. HVOF sprayed coatings had higher content of oxygen and higher density than plasma sprayed coatings. While plasma sprayed coatings showed microcracks originating in certain phases, HVOF sprayed coatings had cracks perpendicular to the surface across the whole layer thickness. In each case the bond strength was determined by the cohesion inside the ceria coating and not by the bondage between the layers. The thermal shock resistance of each type is limited by different properties of the occuring phases caused by impurities of the used powder. However an excellent bondage between YPSZ and ceria can be achieved. Pure ceria thermal barrier coatings are not suitable due to the high diffusion of oxygen and interaction with the MCr AIY bwid coat.


2020 ◽  
Vol 58 (9-10) ◽  
pp. 559-566
Author(s):  
A.P. Umanskii ◽  
A.E. Terentiev ◽  
V.P. Brazhevsky ◽  
A.A. Chernyshov ◽  
V.F. Labunets ◽  
...  

1990 ◽  
Vol 51 (C5) ◽  
pp. C5-393-C5-402
Author(s):  
A. FERRIERE ◽  
G. FLAMANT ◽  
J.-F. ROBERT ◽  
P. PEKSHEV ◽  
I. SMUROV ◽  
...  

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