Study of the characteristics of plasma spray sealing aluminum silicon-polyester coatings

This study shows the homologation of the plasma spray parameters of soft abrasive AlSi - Polyester seals so that they can be applied on the TV2 - 117A compressor engines. The research has aimed at substituting existing sealants with a new class of materials in order to increase the sealing effect under the highest levels of pressure and to provide the air flow temperature of 100-125°C through the compressor. The Metco 601NS material and plasma spray technology were applied on the air labyrinth ring as a part of the TV2-117A turbojet engine compressor in order to obtain soft sealing. The deposit parameters were carefully selected in order to obtain coatings with the best characteristics depending on their application.The flow of helium was taken as a basic parameter in the parameter selection procedure. The coating with the best mechanical and structural properties was deposited on the air labyrinth ring to examine the effect of the coating application in an assembly. The microstructures of deposited layers were estimated with a light microscope and a (SEM) Scanning Electron Microscope. The microstructural analysis of deposited layers was performed according to the Pratt - Whitney standard. The assessment of the mechanical properties of the coatings was done by examining the macrohardness of the sealing layers with the HR15Y method. The coating bond strength was tested by tensile testing. The effect of the air labyrinth ring sealing was tested inside the TV2-117A engine compressor on the test station for a period of 42 hour

Thermal cycling behaviour of plasma sprayed nicr-al-co-y2o3 bond coat in thermal barrier coating system

The aim of this study was to investigate the thermal cycling behaviour of NiCr-Al-Co-Y2O3 bond coating in thermal barrier coating (TBC) system with ZrO2-MgO as a top coating. The coatings were deposited by atmospheric plasma spraying (APS) on stainless steel X15Cr13 (EN 1.4024) substrate. The used composite powder NiCr-Al-Co-Y2O3 was mechanically cladded, and the steel substrates were preheated to 160-180 degrees C. The thermal cycling performance of the obtained bond coat and the effect of formed complex ceramic oxides of the Al2O3-Y2O3 system were tested by heating to 1200 degrees C and cooling in air to 160-180 degrees C. The number of performed thermal cycles was 7, 32 and 79. The quality of the obtained coating, as well as its thermal cycling behaviour, was assessed through the microstructural analysis, microhardness and tensile bond strength measurements, and change in chemical composition and microhardness. The obtained results showed that the steel substrate, bond coat oxidation and interdiffusion at bond coat/substrate interface have a significant influence on changes in chemical composition and microhardness of the bond coat. The correlation between oxidation behaviour of NiCr-Al-Co-Y2O3 bond coat and number of thermal cycles was also discussed

Microstructure and mechanical properties of the Mo-NiCrBSi coating deposited by atmospheric plasma spraying

Prah koji je korišćen u ovom istraživanju (Mo-NiCrBSi) je mešavina dva praha, praha Mo i praha 'samotekuće' legure NiCrBSi, u procentualnom odnosu 75/25%. Nanošenjem ove mešavine prahova dobijena je 'samotekuća' prevlaka na bazi molibdena. Prevlaka je naneta plazma sprej postupkom u atmosferskim uslovima. Kvalitet ovako dobijene prevlake zavisi od nekoliko parametara kao što su: veličina čestica praha koji se nanosi, temperatura nanošenja, vrsta gasova koji se koriste, količina unetog praha, ugao i tempo nanošenja (kontinualno ili sa prekidima), rastojanje plazma sprej pištolja od osnove, temperatura osnove, primenjeni pritisak tokom postupka itd. Sve ove parametre treba pažljivo izabrati kako bi se dobile prevlake sa najboljim karakteristikama, a u zavisnosti od željene primene. U ovom istraživanju su korišćene tri grupe Mo-NiCrBSi prevlaka dobijene sa tri različita rastojanja plazma sprej pištolja od osnove. Mikrostrukture i mehaničke karakteristike dobijenih prevlaka su analizirane da bi se došlo do optimalnih parametara nanošenja tj. do onih koji daju najbolje rezultate.The powder used in this research (Mo-NiCrBSi) was a blend of powders composed of 75% Mo and 25% self-fluxing alloy NiCrBSi. With the deposition of this powder a molybdenum base self-fluxing coating is obtained. The process used for coating deposition was atmospheric plasma spraying (APS). The quality of the coatings deposited by APS depends on several parameters such as the sprayed particle size, the deposition temperature, the combustion gases, the feed speed, the angle and rate of deposition (continuous or intermittent), the spray distance, the temperature of the substrate, the pressure applied during the process, etc. All these parameters should be carefully selected in order to obtain the best coating properties for each application. In this research, three groups of the Mo-NiCrBSi coating specimens were produced with different spray distance parameter. Their microstructure and mechanical properties were analyzed in order to find the optimal spray parameters i.e the ones that give the best structural and mechanical characteristics of the coating

Microstructures and tribological properties of ferrous coatings deposited by APS (atmospheric plasma spraying) on Al-alloy substrate

Korišćenje legura aluminijuma za izradu blokova motora u automobilskoj industriji rezultira smanjenjem težine i uštedama u potrošnji goriva, a samim tim i smanjenjem zagađenja okoline. Prevlake nanete termički, procesom raspršivanja su jedno od rešenja za poboljšanje, inače loših, triboloških karakteristika aluminijuma. U ovom radu su analizirani mikrostruktura i tribološke karakteristike dva tipa prevlaka na bazi gvožđa i upoređene su sa karakteristikama sivog liva kao standardnog materijala za izradu cilindarskih košuljica. Prevlake su nanete na osnovu od Al-Si legure plazma sprej postupkom u atmosferskim uslovima. Za ispitivanja je korišćen tribometar tipa "epruveta na prstenu" u uslovima klizanja sa podmazivanjem, pri brzini klizanja od 0,5 m/s, pređenom putu od 5000 m i normalnom opterećenju od 450 N. Rezultati triboloških ispitivanja pokazuju da, za date uslove ispitivanja obe prevlake imaju zadovoljavajuće vrednosti habanja i trenja i da mogu biti adekvatna zamena za sivi liv kao materijal za izradu cilindarskih košuljica.Using of Al-alloys for producing of engine blocks in automotive industry results in weight savings and lower fuel consumption and therefore reduced pollution. Thermal spray coatings are one of the solutions for improving poor tribological properties of aluminium. In this paper, the microstructures and tribological properties of two types of ferrous thermal spray coatings were analyzed and compared with gray cast iron as a standard material for cylinder blocks. Process used for coating deposition on Al-Si alloy substrate was Atmospheric Plasma Spraying (APS). The pinon- ring tribometer was used to carry out these tests under lubricated sliding conditions, sliding speed of 0.5 m/s, sliding distance of 5000 m and normal load of 450 N. Tribological test results showed that, for the investigated conditions both coatings had satisfactory values of wear and friction and that they could be adequate substitution for gray cast iron as a material for cylinder blocks

Influence of the deposition parameters on mechanical properties and structure of NiCr coating deposited by atmospheric plasma spraying

Prevlaka koja je ispitivana u ovom istraživanju (NiCr prevlaka) dobijena je nanošenjem praha legure nikla i hroma (u procentualnom odnosu 80/20), korišćenjem plazma sprej postupka u atmosferskim uslovima. Ova prevlaka se pre svega primenjuje kako bi povećala otpornost na oksidaciju i koroziju pri visokim temperaturama osnovnog materijala. Kvalitet ovako dobijene prevlake zavisi od više parametara koje treba pažljivo izabrati kako bi se dobile prevlake sa najboljim karakteristikama, a u zavisnosti od željene primene. Pri izboru parametara nanošenja kao osnovni parametar je uzeto rastojanje plazma pištolja od osnove. U ovom istraživanju su korišćene tri grupe uzoraka NiCr prevlaka, dobijene sa tri različita rastojanja plazma pištolja od osnove. Mehaničke karakteristike i mikrostrukture dobijenih prevlaka su analizirane da bi se došlo do optimalnih parametara nanošenja tj. do onih koji daju najbolje rezultate.The coating investigated in this research (NiCr coating) was obtained by the deposition of nickel and chrome alloy powder composed of 80% Ni and 20% Cr. Process used for coating deposition was atmospheric plasma spraying (APS). The application of this coating is primary as protection of the base material against oxidation and hot corrosion. The quality of coatings deposited by APS depends on several parameters, and all these parameters should be carefully selected in order to obtain the best coating properties for each application. During the selection of the deposition parameters the distance of the plasma spray gun from the substrate was chosen as the base parameter. In this research, three groups of the NiCr coating specimens were produced with different spray distance parameter. Their mechanical properties and microstructure were analyzed in order to find the optimal spray parameters i.e. the ones that give the best mechanical and structural characteristics of the coating

Influence of the deposition parameters on mechanical properties and structure of NiCr coating deposited by atmospheric plasma spraying

Prevlaka koja je ispitivana u ovom istraživanju (NiCr prevlaka) dobijena je nanošenjem praha legure nikla i hroma (u procentualnom odnosu 80/20), korišćenjem plazma sprej postupka u atmosferskim uslovima. Ova prevlaka se pre svega primenjuje kako bi povećala otpornost na oksidaciju i koroziju pri visokim temperaturama osnovnog materijala. Kvalitet ovako dobijene prevlake zavisi od više parametara koje treba pažljivo izabrati kako bi se dobile prevlake sa najboljim karakteristikama, a u zavisnosti od željene primene. Pri izboru parametara nanošenja kao osnovni parametar je uzeto rastojanje plazma pištolja od osnove. U ovom istraživanju su korišćene tri grupe uzoraka NiCr prevlaka, dobijene sa tri različita rastojanja plazma pištolja od osnove. Mehaničke karakteristike i mikrostrukture dobijenih prevlaka su analizirane da bi se došlo do optimalnih parametara nanošenja tj. do onih koji daju najbolje rezultate.The coating investigated in this research (NiCr coating) was obtained by the deposition of nickel and chrome alloy powder composed of 80% Ni and 20% Cr. Process used for coating deposition was atmospheric plasma spraying (APS). The application of this coating is primary as protection of the base material against oxidation and hot corrosion. The quality of coatings deposited by APS depends on several parameters, and all these parameters should be carefully selected in order to obtain the best coating properties for each application. During the selection of the deposition parameters the distance of the plasma spray gun from the substrate was chosen as the base parameter. In this research, three groups of the NiCr coating specimens were produced with different spray distance parameter. Their mechanical properties and microstructure were analyzed in order to find the optimal spray parameters i.e. the ones that give the best mechanical and structural characteristics of the coating

Temperature fields in linear stage of friction stir welding effect of different material properties

Friction stir welding is one of the procedures for joining the parts in solid state. Thermo-mechanical simulation of the friction stir welding of high-strength aluminium alloys 2024 T3 and 2024 T351 is considered in this work. Numerical models corresponding to the linear welding stage are developed in Abaqus software package. The material behaviour is modelled by Johnson-Cook law (which relates the yield stress with temperature, strain and strain rate), and the Arbitrary Lagrangian-Eulerian technique is applied. The difference in thermo-mechanical behaviour between the two materials has been analysed and commented. The main quantities which are considered are the temperature in the weld area, plastic strain, as well as the rate of heat generation during the welding process

[Characterization of deposited plasma spray nicralcoy2o3 coating layers on almg1 alloy substrates] [Karakterizacija deponovanih slojeva plazma sprej prevlake nicralcoy2o3 na podlogama od legure almg1]

In this paper, analyzed are the effects of the plasma spray distance on the microstructure and mechanical properties of the NiCrAlCoY2O3 coating layers deposited at atmospheric pressure. The microstructure and mechanical properties of the coating layers are under the influence of the interaction of plasma particles (ions and electrons) with powder particles, providing the transfer of velocity and temperature of the plasma particles onto the powder particles. The effect of the interaction is directly dependent on the time the powder particles were present in the plasma which is defined by distance of the plasma gun from the substrate, depending on the granulation of the powder, the melting point and specific gravity. In order to obtain homogeneous and denser coating layers with high adhesion, in the experiment three distances from the substrate were used: 95 mm, 105 mm and 115 mm. The layers were deposited on thin sheets of AlMg1 aluminum thickness of 0.6 mm. Evaluation of mechanical properties of the layers was carried out by examining microhardness using the HV0.1 method and the bond strength by tensile testing. The morphology of the powder particles was examined on the SEM, while the microstructure of the layers was evaluated under a light microscope in accordance with the Pratt Whitney standard. The results of the experiment showed that the distance from the substrate substantially influenced the structure and mechanical properties of the coating layers. The best deposited layers were examined in the system with the ZrO224%MgO ceramic coating, which have proved to be reliable protectionfrom high temperature and abrasive rocket jet fuel

Characterisation of biocompatible layers of ZrO28%Y2O used in combination with other ceramics to modify the surface of implants

The aim of this study was to deposit multi-functional ZrO28%Y2O3 coating layers using the plasma spray technology and then to characterise such layers. In combination with other biomedical ceramics, this coating is intended for the application in implant surface modification. The examination was focused on the mechanical properties and microstructure layers. Using the atmospheric plasma spraying, duplex ZrO28%Y2O3/Ni22Cr10Al1Y coating system was deposited on the X15Cr13 stainless steel, with two different thicknesses of the bond and ceramic coatings. The microstructure was analysed using an optical microscope, including the assessment of the content of micropores. The morphology of powder particles and ceramic coating surfaces were examined on a scanning electron microscope (SEM). The quality of the ZrO28%Y2O3 layers makes them suitable for the application and combination with other materials to create a system of biomedical or multifunctional coatings

Karakteristike APS i VPS plazma sprej procesa / Characteristics of APS and VPS plasma spray processes / Свойства АПН и ВПН методов плазменного напыления

Plazma je električno provodljiv gas koji sadrži jone, elektrone i neutralne molekule. Takvo stanje materije stvara se preko električnog pražnjenja i može da se održava u stabilnom stanju uvođenjem naizmenične ili jednosmerne struje. U radu je opisana struktura plazme, termodinamičke karakteristike i način stvaranja plazme koji omogućuju primenu plazme kao izvora energije za plazma sprej procese. Generalno, svi postojeći materijali u obliku praha mogu se plazmom deponovati kao prevlake na podlogama od različitih materijala. U plazma provodljivi gas na visokoj temperaturi uvode se čestice praha materijala koje se tope i ubrzavaju do podloge na kojoj formiraju prevlake. Masovna primena plazma sprej prevlaka u svim industrijskim oblastima je od posebnog značaja, jer se sa različitim kombinacijama površinskih slojeva može znatno povećati otpornost mašinskih delova na: habanje, abraziju, eroziju, kavitaciju, koroziju i otpornost na zamor na niskim i povišenim temperaturama, uz povećani resurs i pouzdanost rada delova u eksploataciji. / Plasma is an electrically conductive gas containing ions, electrons and neutral molecules. This state of matter is created by an electrical discharge and can be maintained at steady state by introducing alternating or direct current. The paper describes the structure of plasma, the thermodynamic characteristics and a method of creating plasma that allow the application of plasma as a source of energy for plasma spray processes. In general, all existing materials in a form of powder may be deposited by plasma coating on the surfaces of various materials. At high temperatures, powder material particles are introduced into a conductive plasma gas, melting and accelerating to the substrate to form coatings. The wide use of plasma spray coatings in all industrial areas is of particular importance, because different combinations of surface layers can significantly increase the resistance of machine parts to: wear, abrasion, erosion, cavitation, corrosion and fatigue resistance at low and elevated temperatures with increased resource and reliability of the parts in service. / Плазма —ионизированный газ, содержащий электроны и нейтральные молекулы, способный проводить ток. Данное состояние вещества создается с помощью электрического разряда и может подерживаться в стабильном состоянии при применении переменного или постоянного тока. В статье описаны структура плазмы, ее термодинамические свойства и способы образования, обеспечивающие возможность применения плазмы в качестве энергоносителя в процессе плазменного напыления. В основном, все порошковые вещества могут быть использованы для плазменного напыления покрытий, выполненных из различных материалов.Высокая температура при введении порошковых веществ в плазму способствует ускорению процесса плавки и формирования частиц продукта, напыляемого на покрытие. Рекомендуется широкое применение метода плазменного напыления покрытий во всех промышленных отраслях, так как комбинированные слои покрытия способствуют повышению стойкости деталей машиностроения против: абразивного износа, эрозии, кавитации, коррозии, а также отличаются высокой термостойкостью и устойчивостью к усталости под действием давления и ударных нагрузок. При этом значительно повышается ресурс восстанавливаемой детали и надежность в процессе эксплуатации