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Comparison Studies on Effect of Thermal Spray Coating in Internal Combustion Engine

Saravanan S., Ravichandran M., Balasubramaniyan V.

Mechanics and Mechanical Engineering

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2016

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Vol. 20, nr 1

23--32

EN

The aim of the research outlined in this paper is to evaluate thermal spray processes like Atmospheric Plasma Spraying (APS) for the protection and upgrade of aluminium particularly for the low cost and flexible manufacture of automotive components. A great demand for automobile fuels due to increased rate of consumption and necessity of provide clean air environment in coming years. The automobile industry not only to find alternative fuel sources but also looking for fuel economic and eco friendly vehicles. Thermal spray coatings are depositions of materials which has been melted or plasticized immediately prior to projection onto the substrate. The thermal barrier coating is done on the piston for reducing the emission and thereby improving the efficiency of the internal combustion engine. The Alumina and Silicon Carbide particle were used as coating materials and the effect of the both on the emission and mileage is reported in this paper.

2

Wpływ parametrów natryskiwania na koszty procesu i odporność na korozję powłok natryskiwanych łukowo

Milewski W., Olbrycht A., Pawlik S.

Inżynieria Powierzchni

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2014

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nr 4

31--37

PL

W artykule przedstawiono wyniki badań wpływu odległości i kąta natryskiwania, napięcia łuku, ciśnienia powietrza rozpylającego, rodzaju materiału powłokowego oraz rodzaju układu rozpylającego w pistoletach łukowych na wielkość strat materiału powłokowego, a więc na koszty materiałowe. Badania wykonane zgodnie z normą PN-EN ISO 17836 wykazały, że przy nadmiernym zwiększeniu odległości natryskiwania koszty materiałowe mogą wzrosnąć nawet dwukrotnie. Stwierdzono, że poprzez zastosowanie stopu Zn-Al zamiast Zn można zmniejszyć koszty materiałowe o ok. 10–12%. Zbadano również wpływ chropowatości powłok na ich odporność na korozję.

EN

The test results of the influence of spraying distance, spraying angle, arc voltage, atomizing air pressure, metal type and atomizing chamber type in arc spraying gun on materials loss and coating costs are discussed. Tests, carried out according to PN-EN ISO 17836, showed that too big spraying distance could increase material costs even twice. Replacing of Zn by Zn-Al alloy may decrease the costs of about 10–12%. The effect of coating roughness on the surface coatings corrosion resistance was also investigated.

3

Corrosion of Ni-5 percent Al AND Ni-5 percent Al-Al2O3 flame sprayed coatings of "CastoDyn 8000" torch in 0.01 M H2SO4 and 3.5 percent NaCl solutions

Starosta R., Czoska P.

Journal of KONES

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2010

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Vol. 17, No. 4

471-476

EN

One of methods of regenerating parts of machines is flame thermal spraying, which can be used by ship engine room crew. This method does not require great skill of the operator and is not associated with expensive workstation equipment. Flame sprayed coatings are characterized bv porosity and the presence of oxide inclusions. The presence of pores affects negatively on the corrosion properties of coatings. There is a corrosive environment which may be passed thmugh the pores of the coating to the substrate. This phenomenon is especially dangerous in case of applying cathodic coatings (copper, copper alloys and nickel alloys). The substrate corrosion may then proceed below coating. In the paper researches results of corrosion properties of Ni-Al alloy and Ni-Al-Al2O3 composite coatings were presented. Coatings were obtained by flame spraying of "Casto-Dyn 8000" torch. The studies in 0.01 M H2SO4 and 3.5 NaCl (artificial sea water) environments were realized. Measurements were made following methods: polarization and impedance spectroscopy. Rated coatings are more resistant to the 3.5% NaCl environment than the 0.01 M H2SO4. Corrosion current density for alloy coatings in artificial seawater was 7 miA/cm2 and 232 miA/cm2 environment acidic. Impedance spectroscopy studies showed that the alloy coatings are characterized by more than four times greater resistance in sodium chloride solution than in sulphuric acid solution. Curves flattened in the Nyquist plots may indicate that the appearance of products of corrosion coatings in the pores of the samples during exposure to sea water substitute. The value of corrosion potential in an environment of 3.5% NaCl is about 200 mV lower than 0.01 MH2SO4. Composite coatings Ni-Al-Al2O3 were characterized by a lower corrosion current densities and increased resistance than Ni-Al coatings. This is connected with the operation of non-conducting barrier electrim particles of alumina.