scholarly journals LOCAL MECHANICAL PROPERTIES OF ATMOSPHERIC SPRAYED MOLYBDENUM COATINGS DEPOSITED WITH CASCADED PLASMA TORCH

2020 ◽  
Vol 27 ◽  
pp. 32-36
Author(s):  
Jakub Antoš ◽  
Petra Šulcová ◽  
Kateřina Lencová ◽  
Šárka Houdková ◽  
Josef Duliškovic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plasma Torch ◽  
Thermal Spraying ◽  
Atmospheric Plasma ◽  
Gas Flows ◽  
Mechanical And Tribological Properties ◽  
Spraying Parameters ◽  
Wide Range ◽  
Stable Plasma ◽  
Plasma Sprayed

Increasing interest for industrial use of thermally sprayed coatings leads to development in most thermal spraying technologies, including atmospheric plasma spraying (APS). The latest cascaded torch SinplexPro from Oerlikon Metco incorporates the efficiency advantages of cascaded arc technology into a single-cathode spray gun. It leads to more stable plasma arc across a wide range of gas flows, mixtures and pressures and also highly increases powder throughput. Thermal sprayed molybdenum coatings are widely used for improving wear resistance and sliding properties in many mechanical applications. Results of pure molybdenum coatings sprayed with cascaded plasma torch are not yet fully investigated. In this paper, mechanical properties of atmospheric plasma sprayed molybdenum coatings on steel (S235) substrate are evaluated. Optimization of spraying parameters for spherical Mo powder sprayed by cascaded plasma torch SinplexPro is carried out and the influence on final microstructure, mechanical and tribological properties of molybdenum coatings is analysed.

Development of Nanostructured Al2O3-Ni HVOF Coatings

2006 ◽  
Vol 317-318 ◽  
pp. 539-544 ◽  
Author(s):  
Simo Pekka Hannula ◽  
Erja Turunen ◽  
Jari Keskinen ◽  
Tommi Varis ◽  
Teppo Fält ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Spraying ◽  
Al2o3 Coating ◽  
Hvof Spraying ◽  
Protective Properties ◽  
Hvof Coatings ◽  
Hvof Thermal Spraying ◽  
Plasma Sprayed Coatings ◽  
Plasma Sprayed ◽  
Sprayed Coatings

HVOF thermal spraying has been developed to deposit dense Al2O3-coatings for improved protective properties. As compared to generally used plasma sprayed coatings HVOF coatings can be prepared much denser and thus are better suited for applications where protective properties of the coating are needed. In this paper we describe the development of HVOF spraying technologies for nanocrystalline Al2O3- and Al2O3-Ni-coatings. The microstructure and the mechanical properties of these novel coatings are reported and compared to a conventionally processed Al2O3-coating.

scholarly journals Investigations of microstructure and selected mechanical properties of Al2O3 + 40 wt.% TiO2 coatings deposited by Atmospheric Plasma Spraying (APS)

2019 ◽  
Vol 91 (8) ◽  
pp. 7-11 ◽  
Author(s):  
Monika Michalak ◽  
Leszek Łatka ◽  
Paweł Sokołowski ◽  
Andrzej Ambroziak
Keyword(s):  
Mechanical Properties ◽  
Stainless Steel ◽  
Plasma Spraying ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Good Adhesion ◽  
Spraying Parameters ◽  
Tio2 Coatings

Atmospheric Plasma Spraying (APS) enables deposition of coatings from different materials, including those based on Al2O3 and TiO2. In this work, Al2O3 + 40 wt.% TiO2 coatings were tested. The relationships between mechanical properties, microstructure and spraying parameters (namely: spraying distance and torch scan velocity) were investigated. Commercial -45 + 5 μm powders in agglomerated as- produced state were sprayed onto the stainless steel 1.4301 substrates. The aim of the study was to determine the adhesion, microhardness and roughness of coatings but also to characterize their microstructure. It was observed that coatings sprayed from shorter distance were well melted and revealed good adhesion, but at the same time they were more porous and of lower microhardness than those deposited from the longer spraying distance.

scholarly journals Porosity and Its Significance in Plasma-Sprayed Coatings

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 460 ◽  
Author(s):  
John Gerald Odhiambo ◽  
WenGe Li ◽  
YuanTao Zhao ◽  
ChengLong Li
Keyword(s):  
Working Environment ◽  
Atmospheric Plasma ◽  
Formation Mechanisms ◽  
Multilayer Coatings ◽  
Oxide Coatings ◽  
Spraying Parameters ◽  
Plasma Sprayed Coatings ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Sprayed Coatings

Porosity in plasma-sprayed coatings is vital for most engineering applications. Porosity has its merits and demerits depending on the functionality of the coating and the immediate working environment. Consequently, the formation mechanisms and development of porosity have been extensively explored to find out modes of controlling porosity in plasma-sprayed coatings. In this work, a comprehensive review of porosity on plasma-sprayed coatings is established. The formation and development of porosity on plasma-sprayed coatings are governed by set spraying parameters. Optimized set spraying parameters have been used to achieve the most favorable coatings with minimum defects. Even with the optimized set spraying parameters, defects like porosity still occur. Here, we discuss other ways that can be used to control porosity in plasma-sprayed coating with emphasis to atmospheric plasma-sprayed chromium oxide coatings. Techniques like multilayer coatings, nanostructured coatings, doping with rare earth elements, laser surface re-melting and a combination of the above methods have been suggested in adjusting porosity. The influences of porosity on microstructure, properties of plasma-sprayed coatings and the measurement methods of porosity have also been reviewed.

Microstructure and Mechanical Properties of TiAlNb Coating Deposited by APS and HVOF Spraying

2013 ◽  
Vol 747-748 ◽  
pp. 139-145
Author(s):  
Hong Jie Zeng ◽  
Lai Qi Zhang ◽  
Xin Yu He ◽  
You Cha Zhang ◽  
Pen Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bond Strength ◽  
Thermal Shock ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
Atmospheric Plasma ◽  
Oxide Content ◽  
Thermal Shock Test ◽  
Hvof Spraying ◽  
Lower Porosity

As a material intended for application in hot-dip galvanization, Ti28.15Al63.4Nb8.25Y (at %) coatings were deposited onto 316L stainless steel substrate using high velocity oxygen fuel (HVOF) and atmospheric plasma spray (APS), respectively. The influence of different thermal spraying techniques on the microstructure, phase transformation, porosity, bond strength and hardness values of Ti28.15Al63.4Nb8.25Y coatings was analyzed by scanning electron microscopy (SEM), X-ray diffraction, tensile test and other analysis methods. In addition, the thermal shock test of Ti28.15Al63.4Nb8.25Y coatings was carried out to evaluate the desquamation resistance and the model of invalidation. The results indicated that HVOF Ti28.15Al63.4Nb8.25Y coatings had more uniform and compact morphology than APS Ti28.15Al63.4Nb8.25Y coating and HVOF Ti28.15Al63.4Nb8.25Y coatings have lower porosity and oxide content. The coatings processed by HVOF had higher bond strength, microhardness and thermal shock resistance and displayed better mechanical properties than that prepared by APS.

Relationships between Microstructural and Mechanical Properties of Plasma Sprayed AlSi-Polyester Composite Coatings: Application to Abradable Materials

2014 ◽  
Vol 606 ◽  
pp. 155-158 ◽  
Author(s):  
Yann Duramou ◽  
Rodolphe Bolot ◽  
Jean Louis Seichepine ◽  
Yoann Danlos ◽  
Pierre Bertrand ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Coatings ◽  
Tip Clearance ◽  
Atmospheric Plasma ◽  
Inner Surface ◽  
Polyester Composite ◽  
Overall Efficiency ◽  
Plasma Sprayed ◽  
Abradable Coatings ◽  
Thermal Spray Processes

Abradable coatings are widely used within aeroengines. These materials are applied onto the inner surface of compressor and turbine shroud sections using thermal spray processes, coating the periphery of the blade rotation path. The functionality of an abradable seal is to wear preferentially when rotating blades come into contact with it, while minimizing the over-tip clearance, and improving the overall efficiency of the engine. This study is concerned with the relationships between the microstructure and mechanical properties of atmospheric plasma sprayed AlSi-Polyester composite coatings.

A XPS Study of Atmospheric Plasma Sprayed TiB2 Coatings

2008 ◽  
Vol 368-372 ◽  
pp. 1347-1350 ◽  
Author(s):  
Jun Hu Liu ◽  
Bart Blanpain ◽  
Patrick Wollants
Keyword(s):  
Lattice Oxygen ◽  
Atmospheric Plasma ◽  
Peak Fitting ◽  
Spraying Parameters ◽  
Five Elements ◽  
Xps Study ◽  
Plasma Sprayed

TiB2 coatings were plasma sprayed in air and were studied by XPS. There are five elements in the top surface of the studied coatings, namely, B, C, N, O and Ti. Oxygen pick-up in the coatings results in formation of oxides of boron and titanium. Nitrogen was shown to exist in N-Ti and O-N-Ti in the coating. Depending on the spraying parameters, mono-boride as well as di-boride was also detected in the studied coatings. With careful peak fitting it was shown that oxygen may exist in the coating as dissolved atomic O in addition to as lattice oxygen in the oxide of boron and titanium.

scholarly journals Fatigue behaviour of Plasma Sprayed Titania and Chromia Coatings

2021 ◽  
Vol 349 ◽  
pp. 02009
Author(s):  
Angelos Koutsomichalis ◽  
Antonios Lontos ◽  
George Loukas ◽  
Michalis Vardavoulias ◽  
Nikolaos Vaxevanidis
Keyword(s):  
Static Loading ◽  
Critical Role ◽  
Microstructural Analysis ◽  
Fatigue Behaviour ◽  
Atmospheric Plasma ◽  
Adhesion Properties ◽  
Wide Range ◽  
Plasma Sprayed ◽  
Titania Coatings ◽  
Steel Substrates

Cr2O3 and TiO2 powders were deposited by atmospheric plasma spray (APS) on steel substrates. Microstructural analysis of the coatings showed typical lamellar structure with good coating quality. Fatigue strength was studied by using cyclic testing (measuring with an inhouse-built apparatus the strength of the coated systems under a wide range of impact cycles) and static loading tests (Vickers tests standards with 600N and 1500N) measuring the adhesion properties of the coatings. In low cycles (1x103) Titania coatings exhibited better strength, while at intermediate (4.5x105) and high (1x106) number of impact cycles, both Chromia and Titania coatings exhibited quite similar strength characteristics. At low impact force the thickness of the coatings plays critical role with better performance obtained by Chromia coatings. During static loading both coatings exhibited similar characteristics at the crater diameter but with larger crater depth for Titania. Chromia coatings exhibited higher strength resistance than Titania coatings with better mechanical properties and coating structure.

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