A study on the wear resistance of electroless Ni–P/Diamond composite coatings
TL;DR: In this article, the effect of heat treatment, particle size and phosphorus content on the wear characteristics of composite electroless coating containing diamond particles was investigated and the results indicated substantial increase in wear resistance after the coated sample containing 9-10 wt% P content having fine diamond particle size is annealed around 350°C.
About: This article is published in Wear.The article was published on 2000-04-01. It has received 103 citations till now. The article focuses on the topics: Diamond & Electroless nickel.
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TL;DR: In this article , four types of coatings including Ni-PP, Ni-BP/Ni30 and Ni-NB/Ni60, which were labelled with different deposition time, were prepared on Q235 steel via electroless co-deposition technique.
Abstract: In the field of tribology, black phosphorus (BP) with a layered structure has displayed outstanding performance. To alleviate the high friction and corrosive wear of the friction pairs of marine equipment, four types of coatings including Ni-PP, Ni-BP/Ni30, Ni-BP/Ni60, and Ni-BP/Ni90, which were labelled with different deposition time, were prepared on Q235 steel via electroless co-deposition technique. A ball-on-disk reciprocating tribometer was used to evaluate their tribological properties in 3.5 wt% NaCl, poly-α-olefin 6 (PAO6), and deionized water, respectively. The results show that the Ni-BP/Ni coatings sliding in 3.5 wt% NaCl exhibited better friction reduction and wear resistance than that in deionized water. The Ni-BP/Ni30 coating sliding in 3.5 wt% NaCl showed excellent tribological properties and compared with the Ni-P coating, its average friction coefficient was reduced by 40 % at a load of 4 N and the wear scar cross-sectional area was reduced by 77 % at a load of 10 N. The enhanced tribological properties were attributed to the lamellar slip of BP nanosheets and the formation of a tribofilm composed of NiO, Ni(OH)2, and SiO bonds and an adsorbed film with BP nanosheets. The Ni-BP/Ni coatings present a promising application in seawater corrosive environment.
3 citations
01 Jul 2015
TL;DR: In this article, an optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings is proposed.
Abstract: Electroless nickel coatings are widely popular in various industrial sectors due to their excellent tribological properties. The present study considers optimization of coating parameters along with annealing temperature to improve microhardness and corrosion resistance of Ni-P-TiO2 composite coatings. Grey relational analysis is used to find out the optimal combination of coating parameters. From the analysis, it is confirmed that annealing temperature of the coating has the most significant effect and amount of titanium particles in the coating has some significant effect on corrosion properties of the coating. The same trend is observed in case of combined study of corrosion behavior and microhardness. The surface morphology, phase transformation and the chemical composition are examined using scanning electron microscopy, X-ray diffraction analysis and energy dispersive analysis respectively. The Ni-P-TiO2 composite coating revealed nodular structure with almost uniform distribution of titanium particles and it turns in to crystalline structure after heat treatment. Study of Hardness and Corrosion Resistance of Electroless Ni-P-TiO2 Composite Coatings
3 citations
TL;DR: In this article , the effect of coating thickness on monolithic and composite electroless Ni-P coating wear behaviour was investigated. And the wear rates of each coating were found by measuring the volume loss form multi-pass wear tests.
Abstract: Protective coatings can prolong the lifespan of engineering components. Electroless Ni-P coating is a very hard coating with high corrosion resistance, but low toughness. The addition of NiTi nanoparticles into the coating has shown the potential to increase the toughness of electroless Ni-P and could expand its usability as a protective coating for more applications. However, the study of the tribological behaviour and wear mechanisms of Ni-P-NiTi composite coating has been minimal. Furthermore, there is no studies on the effect of coating thickness on monolithic and composite electroless Ni-P coating wear behaviour. The wear rates of each coating were found by measuring the volume loss form multi-pass wear tests. The wear tracks were examine using a confocal microscope to observe the wear mechanisms. Each sample was tested using a spherical indenter and sharp indenter. It was found that the NiTi nanoparticle addition displayed toughening mechanisms and did improve the coating’s wear resistance. The 9 μm thick Ni-P-NiTi coating had less cracking and more uniform wear than the 9 μm thick Ni-P coating. For both the monolithic and composite coatings, their thicker version had higher wear resistance than their thinner counterpart. This was explained by the often observed trend in coatings where it has higher tensile stress near the substrate interface, which decreases and becomes compressive as thickness increases. Overall, the 9 μm thick Ni-P-NiTi coating had the highest wear resistance out of all the coatings tested.
3 citations
TL;DR: In this article, surface-modified diamond grits embedded into nickel micro-prominences via micro-fabrication and nickel electroforming were used to fabricate novel diamond dressers.
3 citations
TL;DR: In this article, the structure, elemental contents and properties of the diamond-Ni-P composite electroless plating coating were investigated by SEM and EDS, and the dispersants were selected by determining the height of emulsion in the colorimetric cylinder after standing different time.
Abstract: In order to obtain stable and homogeneous diamond-Ni-P composite electroless plating, dispersants were selected by determining the height of emulsion in the colorimetric cylinder after standing different time.The structure,elemental contents and properties of the diamond-Ni-P composite electroless plating coating were investigated by SEM and EDS. Experimental results show that OP-10 of 50mL•L-1 and softex kw of 1g•L-1 have better dispersing effect to diamond powder of 1g•L-1 in water. This composite electroless plating solution can keep stable for more than twelve or eight hours respectively at 85°C. While in the electroless plating solution, Softex kw of 1g•L-1 has better dispersing effect and can be stable for more than two hours at 85°C. The diamond powder grains in the composite coating are homogeneous and the content of carbon is 2.261 wt% under the certain amount of the selected dispersant. When the content of diamond was 5g•L-1 in the solution, the diamond powders were dispersed non-homogeneously in plating and cluster phenomena were appeared. The composite electroless plating coating consists of amorphous Ni-P and diamond powder. Its hardness and porosity are similar to those of the electroless plating Ni-P coating. The wear-resisting is improved greatly,which is 2.6 times of electroless plating Ni-P or 2 times of that after heat treatment at 400°C for one hour.
2 citations
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TL;DR: In this article, a discussion of several important aspects of evaluating wear resistance is presented, focusing on abrasion, which is a large area of the complex field of wear, and the merit of these several qualities should be checked by statistical mathematics to avoid erroneous conclusions and misplaced confidence.
54 citations
Journal Article•
TL;DR: In this article, the formation of the Ni 3 Si compound and wear mechanism of the composite coatings are discussed and structural analysis confirms that a new phase of Ni 3Si compound exists in the Ni-P-SiC deposits annealed at 650 °C for 1 hr.
Abstract: Electroless Ni-P-SiC composite coatings were investigated from the viewpoint of bath formulation, technology and coating properties. A sound and homogeneous deposit containing 25-30 vol. percent SiC can be produced, using an optimum bath formulation and technology. In comparison with Ni-P coatings, Ni-P-SiC composite coatings possess greater hardness and higher porosity, as well as lower adhesion and corrosion resistance. It is a significant advantage that the wear resistance of the composite coating is considerably increased. Heat treatment at high temperature can improve adhesion and wearability of the composite coating. Structural analysis confirms that a new phase of Ni 3 Si compound exists in the Ni-P-SiC deposits annealed at 650 °C for 1 hr. In this paper, formation of the Ni 3 Si compound and wear mechanism of the coatings are discussed.
24 citations
Journal Article•
TL;DR: In this paper, a mixture of microcrystalline nickel and amorphous phases was observed to be a mixture based on X-ray diffraction and transmission electron microscopy.
Abstract: Electroless Ni-P-B deposits with weight percentages of 0.72 P and 4.15 B; 1.87 P and 4.87 B, were observed to be a mixture of microcrystalline nickel and amorphous phases, based on X-ray diffraction and transmission electron microscopy. On annealing, Ni 3 P and Ni 3 B precipitated along with crystalline nickel in one step. The microhardness of the deposits showed typical precipitation hardening behavior, with hardness increasing from about 550 VHN in the as-deposited condition, to about 1000 VHN in the fully crystallized condition
6 citations