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The influence of burnishing on surface texture of regenerative NIAL-15%AL2O3 plasma sprayed coatings

Starosta R.

Journal of Polish CIMAC

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2012

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Vol. 7, no 3

275-283

EN

The purpose of this study was the selection of roller- burnishing parameters of surface Ni-Al-15%Al2O3 composite coatings obtained by "PN 120" plasma torch. Coatings with low surface roughness could be applied as layers increase the service life of torque pumps shaft used on vessels in the sea water systems. After turning, the average surface roughness of plasma sprayed Ni-5%Al-15%Al2O3 coatings was Ra = 1.06 mikro-m. Their average hardness was equal to the 272 HV 2. After pre-treatment, plasma sprayed Ni-Al- 15%Al2O3 coatings were burnishing. Burnishing parameters were as follows: Vn=28,26 m/min, Fn=700N, fn=0,044 m/rev. Burnishing reduces the surface roughness of coatings as compared to machining. After the plastic working, the Ra parameter was reduced to a value of 0.77 m. Total height of waviness profile of machined coatings was 6.23 m. After burnishing, the value of Wt decreased by 0.22 m, to the value of 6.01 m. Studies burnished surface topography of coatings of Ni-5% Al15%Al2O3 overlaid by "PN 120" torch revealed the presence of defects stereometric structure. There are the spalling. After plastic working of plasma coatings, decrease of parameters of the material ratio curve values were observed. For example, the reduced peak height of cut coatings were 1.11 m, after burnishing Rpk value fell to 0.64 mikrom.

2

Właściwości azotowanych powłok regeneracyjnych

Berkowski L.

Obróbka Plastyczna Metali

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2011

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T. 22, nr 1

15-29

PL

W pracy przedstawiono wyniki badań wybranych powłok regeneracyjnych nałożonych na próbki różnymi metodami i azotowanych w różny sposób (azotowanie jonowe i gazowe). Badano zmiany geometrii powierzchni po azotowaniu, wyznaczono profile twardości powłok przed i po azotowaniu oraz przeprowadzono próby ścierania. Badania wykazały, że azotowanie nie powoduje istotnego wzrostu odporności na ścieranie powłok ze stali stopowych i powłok ze stopu niklu, które wykazały odporność na zuzycie jeszcze przed obróbką cieplnochemiczną. Korzystne skutki azotowania stwierdzono na powłokach ze stali SpG3-S1.

EN

The paper presents examination results of selected regenerative coatings applied on to the samples by various methods and nitrided in various ways (ion and gas nitriding). Surface geometry changes after nitriding have been examined, coating hardness profiles before and after nitriding have been determined abrasion tests have been performed. The investigation has shown that nitriding does not result in a significant increase of abrasion resistance of alloy steel coatings and coatings of nickel alloy which have revealed wear resistance prior to the thermochemical treatment. Advantageous results of nitriding have been found on coatings of SpG3-S1 steel.

3

Testing Of Regenerative Thermal Spraying Ni-Al Alloy Coatings

Starosta R.

Journal of Polish CIMAC

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2008

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Vol. 3, no 2

9-13

EN

The article presents the results of testing of Ni-Al alloy coatings with different chemical constitution and phase composition, which might replace currently used electrolytic chromium coatings .Crust chromium coatings are suitable for reconditioning of machine parts because of their very good maintenance properties. However, due to toxicity of electrolylic chromium bath, their application tends to be restricted. Thermal flame and plasma spraying technologies were chosen for nickel aluminium coating application. Obtained coatings were distinguished by significant porosity of structure and surface roughness. The thickness of coatings ranged from 440 to 683 mm. Microhardness of coatings was not related to applied metal plating technology but to chemical constitution and phase composition. The more aluminium content in alloy coating the harder the coatings were. The hardness of coatings which resulted from NiAl phase was ca 250 HV 0.04. Flame spray coatings are distinguished by nearly 10 times bigger corrosion current density when compared with plasma spray coatings .The value of corrosion potential is influenced by structure and chemical constitution of coatings. The more aluminium content the lower Ecorr.