scholarly journals Microstructure Study and Morphology of Ni / Nano Al2O3 Composite Coating Synthesied by Electroless Plating

2021 ◽  
Vol 14 (3) ◽  
pp. 1-7
Author(s):  
Hala M. Kadhim

The electroless deposition method was used to prepare Ni-based nanocomposite coatings, this approach represents an alternate way of having coatings on the different substrates. Most of the previous literatures on this subject and work deals with a study the effect of the process conditions and, Bath composition on the microstructure at the macroscale of Ni-Al2O3 composite coatings. Though, effect on the step structure of the composition of the bath and microstructure are little, the present work aims to study the effect of hard ceramic Al2O3 nanoparticles at different concentrations (0.0, 0.5, 1.0, 2, 4) g/L, on the phase structure, microstructure and morphology of Al2O3 nanocomposite coating, in order to enhance the mechanical, plysical and chemical properties of nanocomposite coating. In this paper, An X-Ray diffraction method, spectroscopy (EDS), energy dispersive, and scanning electron microscope (SEM) were studied in the phase structure, chemical composition and morphological nanocomposition coatings. In the present paper, is evident from EDS study that the composite coating consists of Ni and nanoparticles of Al2O3. The micrograph study of the EDS showed that A flat and smooth surface is present in the deposited nanocomposite coating. Uniform distribution of nanoparticles of alumina within Ni-Matrix. And the XRD study showed the crystalline structure of the Ni- Al2O3 nanocomposite coating.

2010 ◽  
Vol 97-101 ◽  
pp. 1558-1561 ◽  
Author(s):  
Li Jie Wang ◽  
Ya Zhe Xing ◽  
Hong Bo Wang ◽  
Jian Min Hao

Three composite coatings were prepared by nitriding-sulfurizing processing of Ti-6Al-4V alloy at different sulfurizing temperatures. The microstructure and phase structure of the coatings were examined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Furthermore, the hardness of the coatings was measured. The effect of the sulfurizing temperature on microstructure of coatings was investigated. The results indicated that the composite coating was mainly comprised of titanium nitrides, titanium sulfides, and titanium. It was found that the phase composition of composite coating changed with the variation of the sulfurizing temperature.


2011 ◽  
Vol 675-677 ◽  
pp. 747-750
Author(s):  
B. Han ◽  
Dong Ying Ju ◽  
Xiao Guang Yu

Water cavitation peening (WCP) with aeration, namely, a new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration a standard N-type almen strips of spring steel SAE 1070 was treated byWCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by means of the Almen-scale and X-ray diffraction method, respectively. The optimal fluxes of aeration and the optimal standoff distances were achieved. The maximum of arc height value reach around 150μm. The depth of plastic layer observed from the results of residual stresses is up to 150μm. The results verify the existence of macro-plastic strain in WCP processing. The distributions of residual stress in near-surface under different peening intensity can provide a reference for engineers to decide the optimal process conditions of WCP processing.


2008 ◽  
Vol 373-374 ◽  
pp. 754-757 ◽  
Author(s):  
Dong Ying Ju ◽  
B. Han

Water cavitation peening (WCP) with aeration is a novel surface enhancement method. A new ventilation nozzle with aeration is adopted to improve the process capability of WCP by increasing the impact pressure induced by the bubble collapse on the surface of components. In this study, in order to investigate the process capability of the WCP with aeration, a standard N-type almen strips of spring steel SAE 1070 was treated by WCP with various process conditions, and the arc height value and the residual stress in the superficial layers were measured by X-ray diffraction method. The optimal fluxes of aeration and the optimal standoff distances were achieved.


RSC Advances ◽  
2018 ◽  
Vol 8 (22) ◽  
pp. 12138-12145 ◽  
Author(s):  
Zong-wei Jia ◽  
Wan-chang Sun ◽  
Fang Guo ◽  
Ya-ru Dong ◽  
Xiao-jia Liu

Ni–Co–Al2O3 composite coatings were prepared by pulsed electrodeposition and electrophoresis–electrodeposition on aluminum alloy.


2020 ◽  
Vol 34 (27) ◽  
pp. 2050243
Author(s):  
Hui Fan ◽  
Jie Jiang ◽  
Yangpei Zhao ◽  
Shankui Wang ◽  
Zhijing Li

Ni–Al2O3 composite coatings were prepared with a modified Watt’s bath by using jet electrodeposition method. As the key process parameter, current density and the addition of Al2O3 nanoparticles in electrolyte were studied about the effect on the surface morphology and co-deposition of Al2O3 nanoparticles of composite coating. The mechanical and tribological properties of the composite coating were also tested. The results show that properly increasing the current density and Al2O3 addition can increase the co-deposition of nanoparticles in the coating and promote the formation of a dense and refined coating structure. Using the optimized process parameters of current density (300 A/dm2) and Al2O3 addition (30 g/L), the co-deposition of Al2O3 in the composite coating can reach a maximum of 13.1 at.%. The hardness of the coating reaches the peak at 623 HV. The wear rate of the composite coating is also greatly reduced with optimized parameters.


2015 ◽  
Vol 228 ◽  
pp. 132-137 ◽  
Author(s):  
B. Łosiewicz ◽  
Grzegorz Dercz ◽  
Magdalena Popczyk

The Ni-Mo+MoO2composite coatings were obtained onto the steel substrate using anin situco-deposition of a Ni-Mo alloy and MoO2powder particles maintained in suspension in the potassium pyrophosphate bath. To characterize the physical and chemical properties of the obtained coatings, SEM, EDS, and XRD methods, were applied. It was found that the co-deposited MoO2particles strongly influenced the properties of the Ni-Mo alloy coating. In comparison with the comparable Ni-Mo deposit containing 45 at.% of Mo, the presence of MoO2embedded into the composite coating diminished the content of Mo alloyed with Ni to 23 at.%. The electrodeposited Ni-Mo+MoO2composite coating obtained under proposed electrochemical conditions contained 25 at.% of MoO2. The effect of the embedded MoO2as composite component on changes of the surface morphology and structure of the Ni-Mo binary alloy, was also discussed.


Author(s):  
Wei Jiang ◽  
Lida Shen ◽  
Kai Wang ◽  
Zhanwen Wang ◽  
Zongjun Tian

The Ni-Co/SiC composite coatings were prepared via jet electrodeposition in the presence of magnetic field. The microstructure and texture orientation of the composite coatings were analyzed via field emission scanning electron microscopy, three-dimensional profiling, and X-ray diffraction. The microhardness and wear resistance were characterized by a microhardness tester and a friction–abrasion testing machine. The results indicated that nano-SiC particles improved the surface morphology of the Ni-Co/SiC composite coating. In jet electrodeposition, globular structure aggregation began to form protrusions in the Ni-Co/SiC composite coating due to nanoparticle agglomeration when 6 g/L of nano-SiC was added. The Ni-Co/SiC (6 g/L) composite coating became uniform and densification by jet electrodeposition in magnetic field, with higher microhardness and better wear resistance. The microhardness of the Ni-Co/SiC composite coating increased to 626 ± 14 HV, and the corresponding friction coefficient was as low as 0.317.


2012 ◽  
Vol 472-475 ◽  
pp. 70-73
Author(s):  
Ya Xu Jin ◽  
Yu Ming Tian ◽  
Qiu Shu Li

Electroless nickel plating with potassium titanate whisker was co-deposited on medium carbon steel substrates. The microstructure of the composite coatings was investigated. The effect of aging temperature on the microstructure of the composite coatings was studied using X-ray diffraction. The results indicate that the composite coatings will turn into crystal state with increasing heat treatment temperature. Experimental results also show that a maximum hardness is achieved for the composite coating after heat treatment at 400°C for 1 hour. The corrosion resistance and tribological properties of the composite coatings are not inferior to those of electroless Ni-P coating.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1438-1443 ◽  
Author(s):  
ZHENTING WANG ◽  
LILI CHEN ◽  
XIANYOU ZHANG

A metal matrix composite coating reinforced by ZrC - ZrB 2 particulates has been successfully fabricated utilizing the in situ reaction of Zr , B 4 C and Fe pre-placed mixed powders by gas tungsten arc welding (GTAW) cladding process. Various volume fraction of ZrC - ZrB 2 particulates composite coatings were produced through cladding different weight ratios of Zr + B 4 C (30%, 50%, 70%) to improve the wear resistance of AISI1020 steel substrate. The Microstructure of the coating was analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy-dispersive spectrum (EDS), meantime microhardness and wear resistance at room temperature of the composite coating were examined by means of Microhardness Tester and Wear Tester, respectively. The results show that the main phases of the composite coating obtained by GTAW are ZrC , ZrB 2 and α- Fe , ZrC exhibits hexahedron and petal shapes, ZrC - ZrB 2 compound presents acicular and clubbed forms. With the increase of content of Zr + B 4 C , the maximum volume fraction of ZrC - ZrB 2 particulates can reach 16.5%, microhardness is up to 1300HV, and wear resistance is about twenty times higher than that of AISI1020 steel substrate.


2011 ◽  
Vol 189-193 ◽  
pp. 672-675
Author(s):  
Yu Hai Li ◽  
Yan Zhao ◽  
Bao Yi Li

The Al2O3-ZrO2 composite ceramic coatings were prepared on 2A12 aluminum alloy by Microarc oxidation in the mixed electrolyte of 40g/L Na2SiO3 and 8g/L Na2WO4 solution containing different ZrO2 content particles. The thickness of the coatings was measured by an eddy current thickness meter. Microstructure and phase composition were analyzed by scanning election microscopy (SEM) and X-Ray diffraction (XRD), respectively. The experimental results show that ZrO2 in electrolyte can promote coatings growth; Al2O3-ZrO2 composite ceramic coatings consist of α-Al2O3, t-ZrO2, m-ZrO2, and ZrO2 is located in island-like discharge channels and does not destroy the integrity of composite coatings; There is scarcely any erosion on the surface of Al2O3-ZrO2 composite coatings because the intermediate product Zr(OH)4 could suppress composite coating corrosion.


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