Effect of alumina content on surface morphology and hardness of Ni-P-Al2O3(α) electroless composite coatings

Alirezaei, S.; Monirvaghefi, S. M.; Salehi, Mehdi; Saatchi, A.

doi:10.1016/j.surfcoat.2003.11.013

Cited by 82 publications

(26 citation statements)

References 12 publications

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“…The presence of Al 2 O 3 in the coatings was confirmed by EDS spectrum analysis and chemical analysis report showed Al 2 O 3 is about 2.5 wt% with a reduction in phosphorus content to 9.8 wt%. Thus the decrease in phosphorous content is related to presence of alumina content in NiP coating which is in agreement with the micron size Al 2 O 3 co-deposited in NiP matrix [20]. indicates that the both coatings has lattice disorder which affects the crstallinity of the coating.…”

Section: Methodssupporting

confidence: 78%

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Influence of Nano Al2O3 Particles on the Adhesion, Hardness and Wear Resistance of Electroless NiP Coatings

Karthikeyan¹,

Vijayaraghavan²

2015

IJMMM

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Abstract-In this present study electroless NiP coatings and NiP-Al 2 O 3 coatings had been deposited on a mild steel substrate. The surface morphology of both the coatings had studied using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction technique. Adhesion, hardness and wear behavior were investigated and compared for NiP and NiP-Al 2 O 3 coatings. Optical micrograph images were used for the evaluation of adhesion of coatings which found sufficient and acceptable according to VDI 3198 standard. Hardness of the coating had been evaluated based on depth sensing techniques and substrate effect had avoided by maintaining depth to coating thickness ratio less than 0.1. Due to co-deposition of Al 2 O 3 particles the hardness of NiP coatings increased by 20.5% (7.8 GPa to 9.4 GPa). Dry sliding wear tests were conducted on PLINT TE66 micro scale tester against steel ball of hardness 800 HV. Wear resistance of NiP coatings increased with increase in sliding distance. The co-deposition of Al 2 O 3 particles in NiP matrix arrest the deformation during sliding of steel ball and thus wear resistance of NiP-Al 2 O 3 coatings is superior to NiP coatings. Wear crater morphology were studied using SEM and EDS. Adhesive wear mechanics was observed in NiP coatings and combination of adhesive and abrasive wear mechanism were found in NiP-Al 2 O 3 coatings.

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Section: Methodssupporting

confidence: 78%

“…The hardness value obtained for NiP-Al 2 O 3 is 9.4 GPa. An increase in 1.6 GPa hardness value is due to the existence of hard Al 2 O 3 particles which acts as a barrier to plastic deformation of NiP matrix [20]. [23].…”

Section: Methodsmentioning

confidence: 99%

Influence of Nano Al2O3 Particles on the Adhesion, Hardness and Wear Resistance of Electroless NiP Coatings

Karthikeyan¹,

Vijayaraghavan²

2015

IJMMM

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“…It has been reported that semi-coherent Ni 3 P phases are created approximately at 400°C and consequently microhardness increases, whereas the size of Ni 3 P precipitates increases with increasing of temperature to 600°C and these phases changed from semicoherent to noncoherent state. 18 Microstructural changes in ENi-P matrix as a result of heat treatment above 200°C are one of the effective factors that increase the microhardness of ENi-P coatings. Figure 5 shows x-ray diffractograms of the deposits obtained in different conditions listed in Table 3.…”

Section: Microhardness Of Electroless Eni-p Depositsmentioning

confidence: 99%

Investigation and optimization of SDS and key parameters effect on the nickel electroless coatings properties by Taguchi method

et al. 2010

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In this research, the influence of anionic surfactant sodium dodecyl sulfate (SDS), pH, substrate finishing, and annealing temperature on the surface morphology and hardness of the electroless nickel phosphorus (ENi-P) coatings were studied. Taguchi's experimental design method was used. Parameters selected in three levels and L9 from orthogonal robust array design were employed. Surface roughnesses of the deposits were measured using a stylus instrument. Scanning electron microscope and x-ray diffraction analysis were implemented to study surface morphologies and phase composition, respectively. Microhardness of the ENi-P deposits was measured using a microhardness tester at three trials per sample. The results showed that addition of the SDS increases the microhardness and improves surface morphology. Finally, optimum condition was achieved as, surfactant concentration equal to 1.5 g/L, pH 5.5, substrate finishing provided with emery paper no. 2000, and annealing temperature equal to 400°C.

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“…After the electroless processing, some samples were heat treated by aging them at 500°C for 60 min in an air-furnace atmosphere. 18 Other specimens were not heat treated after the electroless processing. The heat treatment was not longer than 24 h, applied after the electroless processing of the specimens.…”

Section: Experimental Partmentioning

confidence: 99%

“…9 Nickel with an amorphous structure has a lower hardness than nickel with a crystalline structure. 4,[10][11][12][16][17][18][19][20][21][22][23][24][25][26][27][28] After the heat treatment, the structure of the coating is more crystalline; moreover, the intermetallic nickel phosphide (Ni 3 P) phase appears. 9,10,15 The hardness of coatings can increase with the appearance of the intermetallic Ni 3 P phase and a higher crystallinity of nickelphosphorous coatings.…”

Section: Introductionmentioning

confidence: 99%

Heat treatment of electroless Ni-P layers on an austenitic stainless-steel substrate

Maretić¹,

Smoljan²,

Iljkić³

2017

Mater. Tehnol.

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Properties of electroless deposited nickel-phosphorous coatings on an austenitic stainless-steel substrate were investigated. The main study was focused on the influence of heat treatment on the microhardness and microstructure analysis of electroless Ni-P coatings. A nickel-phosphorous coating was deposited without nickel-strike pre-coating treatment. An electroless Ni-P layer was deposited on a stainless-steel substrate. Sodium hypophosphite was used as the reducing agent. The microstructure and morphology of heat-treated electroless specimens were analyzed with optical and scanning electron microscopy. Adhesivity was estimated with a Vickers indenter. Based on the experimental results, it can be concluded that heat-treated electroless nickel-phosphorous coatings have a higher microhardness than non-heat-treated electroless nickel-phosphorous coatings. An analysis of the Vickers indentation results showed that the proposed electroless process gives satisfactory results. Keywords: electroless, deposition, coatings, heat treatment, stainless steel, micro-hardness Preiskovane so bila lastnosti kemijsko nane{ene plasti nikelj -fosfor, na podlagi iz avtenitnega nerjavnega jekla. Glavni {tudij je bil usmerjen na vpliv toplotne obdelave na mikrotrdoto in analizo mikrostrukture kemijsko nane{enega Ni-P nanosa. Nanos nikelj -fosfor je bil nane{en brez predhodnega premaza. Kemijski nanos Ni-P je bil nane{en na osnovo iz nerjavnega jekla. Natrijev hipofosfid je bil uporabljen kot redukcijsko sredstvo. Mikrostruktura in morfologija kemijsko nane{enega vzorca je bila analizirana s svetlobno in z vrsti~no mikroskopijo. Adhezivnost je bila dolo~ena z vtiskovanjem po Vickers piramidi. Na osnovi rezultatov preizkusov je mogo~e zaklju~iti, da ima toplotno obdelan kemijski nanos nikelj -fosfor vi{jo trdoto kot neobdelan kemijski nanos nikelj -fosfor. Analiza rezultatov Vickers vtiskov je pokazala, da predlagani kemijski postopek daje zadovoljive rezultate.

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Effect of alumina content on surface morphology and hardness of Ni-P-Al2O3(α) electroless composite coatings

Cited by 82 publications

References 12 publications

Influence of Nano Al2O3 Particles on the Adhesion, Hardness and Wear Resistance of Electroless NiP Coatings

Influence of Nano Al2O3 Particles on the Adhesion, Hardness and Wear Resistance of Electroless NiP Coatings

Investigation and optimization of SDS and key parameters effect on the nickel electroless coatings properties by Taguchi method

Heat treatment of electroless Ni-P layers on an austenitic stainless-steel substrate

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