The Effect of Al2O3 Concentration on Properties of Ni-W-P-Al2O3 Electroless Composite Coating

2012 ◽  
Vol 468-471 ◽  
pp. 1163-1166 ◽  
Author(s):  
Wan Chang Sun
Keyword(s):  
Corrosion Resistance ◽  
Composite Coating ◽  
Potentiodynamic Polarization ◽  
Steel Substrate ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Plating Bath ◽  
Hardness Tester ◽  
Al2o3 Concentration ◽  
Plating Solution

Ni-W-P-Al2O3 electroless composite coating was successfully co-deposited on 45 steel substrate using electroless plating. Optical microscope (OM), micro-hardness tester and potentiodynamic polarization were used to analyze the morphology, micro-hardness and corrosion resistance of the composite coating. The effect of Al2O3 concentration in the plating solution on the micro-hardness and corrosion resistance of the composite coating was mainly discussed. The results show that Al2O3 particles co-deposit with Ni-W-P homogeneously. The micro-hardness and corrosion resistance of the coating are improved with the increasing of Al2O3 concentration in the plating bath, and then decrease at a high Al2O3 concentration.

Characterisation of WC-17Co and WC-9Ni HVOF Sprayed Cermet Coatings

2016 ◽  
Vol 840 ◽  
pp. 331-335
Author(s):  
Nur Amira Mohd Rabani ◽  
Zakiah Kamdi
Keyword(s):  
Steel Substrate ◽  
Optical Microscope ◽  
Binder Phase ◽  
High Porosity ◽  
Tungsten Carbides ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hardness Tester ◽  
Vickers Micro Hardness

Cemented tungsten carbides have been paid much attention due its better mechanical properties with excellent combination of hardness and toughness characteristics. The hard WC particles in the coating provide hardness and wear resistance, while the ductile binder such as Co and Ni contribute to toughness and strength. WC-17wt.% Co and WC-9wt.% Ni powders have been sprayed by the HVOF method to form coatings approximately 300μm and 150μm thick onto AISI 1018 steel substrate. Both coatings have been prepared and supplied by an external vendor. The coatings were examined using optical microscope (OM), scanning electron microscope (SEM), and X-Ray diffraction (XRD). The hardness of both coatings were also measured using Vickers micro-hardness tester. The microstructure of the coatings has been analyzed and found to consist of WC, brittle W2C phase, metallic W phase, and amorphous binder phase of Co and Ni. It is found that WC-Ni has a higher hardness value compared to WC-Co due to high porosity distribution.

Tungsten Inert Gas (TIG) Cladding of TiC-Fe Metal Matrix Composite Coating on AISI 1020 Steel Substrate

2020 ◽  
Vol 1159 ◽  
pp. 19-26
Author(s):  
Anil Kumar Das ◽  
Sujeet Kumar ◽  
Mayank Kumar Chaubey ◽  
Waquar Alam
Keyword(s):  
Composite Coating ◽  
Gas Flow ◽  
Steel Substrate ◽  
Variable Parameter ◽  
Scanning Speed ◽  
Inert Gas ◽  
Hardness Profile ◽  
Micro Hardness ◽  
Gas Flow Rate ◽  
Hardness Tester

TiC – Fe composite coating was produced on AISI 1020 steel by the tungsten inert gas (TIG) cladding process to increase the hardness and wear resistance properties of the substrate. In this paper authors have investigated the effect of process parameters on the microstructure and hardness value of the coated layer. In this TIG cladding process the variable parameter is only current, whereas the other parameters such as scanning speed, standoff distance, and voltage and gas flow rate are fixed. Fe and TiC powders were mixed in the proper ratio of 80wt% - 20wt% and 90wt% - 10wt% respectively. The microstructure and micro-hardness value of the samples were investigated by the scanning electron microscope (SEM) and Vickers micro hardness tester. The result of SEM shows the distribution of the coating powder in the cladded zone. Micro hardness profile shows the variation of the hardness value in the cladded zone as well as in the substrate. The hardness value decreases with increase in distance from top surface of the cladded layer, which is due to difference in cooling rate. Also, the hardness value of cladded layer decreases with increase in current from 140A to 150A. The maximum hardness value of cladded layer was achieved as 262 HV0.05 with 140A current and composition of 90 wt.% - 10wt% (Fe - TiC), which was nearly two times higher than that of the as received AISI 1020 steel substrate. Keywords TIG, Microstructure, Micro hardness, Titanium Carbide (TiC), Iron (Fe) powder.

Characteristics of Laser Cladded Nickel-Based Chromic Carbide Composite Coatings

2017 ◽  
Vol 893 ◽  
pp. 340-344
Author(s):  
Sheng Dai ◽  
Dun Wen Zuo ◽  
Xian Rui Zhao ◽  
Jin Fang Wang
Keyword(s):  
Wear Resistance ◽  
Carbon Steel ◽  
Composite Coating ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Surface Hardness ◽  
Micro Hardness ◽  
Wear Properties ◽  
Hardness Tester ◽  
Metallurgical Bonding

To improve the surface hardness and wear resistance of metal parts. Ni-based chromic carbidecomposite coating was prepared on the carbon steel (0.45 mass% C) substrates by laser cladding. Microstructure and wear properties of composite coatings were investigated by SEM, EDS, XRD, Vickers micro-hardness tester and wear machine. The results show that good metallurgical bonding between the Ni-based chromic carbidecomposite coating and carbon steel substrate. Micro-hardness of Ni-based Cr3C2 composite coating along the layer depth presents an evident stepladder distribution. The average micro-hardness of the laser clad coating is about 950 HV. The result of wear experiment shows that Ni-based Cr3C2 composite coating processes good wear resistance.

Effect of High-Energy Shot-Peening on H13 Tool Steel Ion-Nitriding

2011 ◽  
Vol 393-395 ◽  
pp. 67-71
Author(s):  
Zhi Lan Ren ◽  
Xin Heng Wang
Keyword(s):  
Corrosion Resistance ◽  
Shot Peening ◽  
High Energy ◽  
Optical Microscope ◽  
Micro Hardness ◽  
Ion Nitriding ◽  
H13 Steel ◽  
Hardness Tester ◽  
Nitride Layers ◽  
Hardness Gradient

High-energy shot-peening on H13 steel after quenched. The samples with or without high-energy shot-peening were ion-nitrided at 520°C for 3h．The Microstructure，nitriding depth, hardness gradient, surface phase and Corrosion resistance of the nitride layers were compared between the high-energy shot-peening samples and the original samples using optical microscope, micro-hardness tester, X-ray diffraction and CH1660A electrochemical test. Results show that the high-energy shot-peening greatly speeds up the nitriding on the H13 steel at 520°C for 3h.. The depth of ion-nitriding layer after shot peening is from 0.11mm to 0.16mm, micro-hardness of the surface layer is from 998HV0.5 to 1105HV0.5, The hardness gradient is slightly flat . Phase structure and content of the surface is different by Powerful shot-peening and not. Corrosion resistance of the samples by high-energy shot-peening is significantly improved because it is easier to form a stable passive film.

The Effect of Heat Treatment on Corrosion Resistance of Ni-W-P-Al2O3 Composite Coating

2012 ◽  
Vol 468-471 ◽  
pp. 1177-1180
Author(s):  
Wan Chang Sun
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Annealing Temperature ◽  
Steel Substrate ◽  
Optical Microscope ◽  
Amorphous Structure ◽  
Crystal Defects ◽  
X Ray Diffraction ◽  
X Ray

Abstract. Ni-W-P-Al2O3 electroless composite coating was successfully co-deposited on 45 steel substrate using electroless plating. Optical microscope (OM), X-ray diffraction (XRD) and potentiodynamic polarization were used to analyze the morphology, microstructure and corrosion resistance of the composite coating. The results show that Al2O3 particles co-deposit homogeneously, and the structure of the composite coating as deposited is amorphous and crystallite. After heat treatment, the amorphous structure of the composite coating appears a precipitation transformation. When annealing at 400°C, because of the emergence of crystal defects brought out by the precipitation of crystal phases, the composite coating exhibits the lowest corrosion resistance. As the annealing temperature rising to 600°C, the crystalline structure continually grows up and the precipitation transformation tends to be completed. Then the crystal defects decreases which results in an improvement to the corrosion resistance of the composite coating.

Study of Corrosion Performance of Electroless Ni-P Coating with Molybdenum Disulfide Nanoparticles

2008 ◽  
Vol 373-374 ◽  
pp. 256-259 ◽  
Author(s):  
Xian Guo Hu ◽  
Wen Ju Cai ◽  
Jiu Cong Wan ◽  
Yu Fu Xu ◽  
Xiao Jun Sun
Keyword(s):  
Corrosion Resistance ◽  
Molybdenum Disulfide ◽  
Composite Coating ◽  
Steel Substrate ◽  
Surface Film ◽  
Composite Coatings ◽  
Salt Spray ◽  
Optical Microscope ◽  
Corrosion Mechanism ◽  
Corrosion Properties

The electroless nickel-phosphor coatings containing molybdenum disulfide nanoparticles were prepared and analyzed in this paper. The effects of incorporation of MoS2 into the Ni-P coating on the morphology of the coating surface and corrosion properties were also studied. Corrosion tests were conducted inside a salt spray box with NaCl solution (5.0 wt%). The corrosional surfaces were studied and analyzed through optical microscope, X-ray spectrometer (XRD) and scanning electron microscopy (SEM). The investigation on the relationship between heat-treatment and the corrosion resistance of the coatings showed that the corrosion resistance of the composite coating became worse because of the occurrence of transformation from non-crystalline to crystalline, and then increased the metastable intergradation of the composite coating. Meanwhile, the experimental results also showed that corrosion resistance of the coating containing MoS2 was higher than that of steel substrate. The corrosion mechanism of the composite coatings was mainly ascribed to the formation of micro-cell around the nanosized MoS2 particles, and the active ion like Cl- destroyed the surface film and induced the corrosion towards the inside part of coating.

Influence of CNTs Concentration on the Microstructure and Electrochemical Properties of Ni-P-MWNTs Composite Coating

2014 ◽  
Vol 809-810 ◽  
pp. 610-614 ◽  
Author(s):  
Miao Miao Tian ◽  
Wan Chang Sun ◽  
Qin Shi ◽  
Ying Wang ◽  
Qing Hao Yang
Keyword(s):  
Carbon Nanotubes ◽  
Corrosion Resistance ◽  
Composite Coating ◽  
Corrosion Potential ◽  
Steel Substrate ◽  
Plating Bath ◽  
Multi Walled Carbon Nanotubes ◽  
P Matrix ◽  
Microscopic Morphology ◽  
Walled Carbon Nanotubes

Ni-P-multi-walled carbon nanotubes (Ni-P-MWNTs) composite coating was successfully co-deposited on 45 steel substrate by electroless plating. The microscopic morphology of Ni-P-MWNTs composite coating was observed by SEM. The influences of CNTs concentration in plating bath on the microstructure and corrosion resistance of the composite coating were investigated. The results indicated that the deposited composite coating shows dispersed CNTs and continuous Ni-P matrix, and there are no pores and cracks and other defects at the interface between the substrate and composite coating, and the thickness of the composite coating is about 50 μm. The Ni-P-MWNTs composite coating with 0.3g/L CNTs in bath displayed the best corrosion resistance, the corrosion potential of the composite coating is-0.372V.

Evolutions of Microstructure for Multilayered Al-Mg Alloy Composites by Accumulation Roll Bonding (ARB) Process

2011 ◽  
Vol 411 ◽  
pp. 527-531
Author(s):  
Bing Zhang ◽  
Zhong Wei Chen ◽  
Shou Qian Yuan ◽  
Tian Li Zhao
Keyword(s):  
Multilayer Structure ◽  
Optical Microscope ◽  
Alloy Layer ◽  
Mg Alloy ◽  
Micro Hardness ◽  
Roll Bonding ◽  
Fine Grained ◽  
Hardness Tester ◽  
Average Grain Size ◽  
Evolution Of Microstructure

In this paper, accumulative roll bonding (ARB) has been used to prepare the Al/Mg alloy multilayer structure composite materials with 1060Al sheet and MB2 sheet. The evolution of microstructure of the cladding materials during ARB processes was observed by optical microscope, scanning electron microscopy, and micro-hardness was measured by micro-hardness tester. The results show that a multilayer structure material of Al/Mg alloy with excellent bonding characteristics and fine grained microstructure was prepared by ARB processes. With the ARB cycles increasing, Mg alloy layer in multilayer composite material was necked and fractured, and the hardness of the Al and Mg alloy was increased. Average grain size was less than 1μm after ARB4 cycles.

scholarly journals Microstructural and Corrosion Behavior of High Velocity Arc Sprayed FeCrAl/Al Composite Coating on Q235 Steel Substrate

Coatings ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 542 ◽  
Author(s):  
Ndumia Joseph Ndiithi ◽  
Min Kang ◽  
Jiping Zhu ◽  
Jinran Lin ◽  
Samuel Mbugua Nyambura ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Composite Coating ◽  
High Velocity ◽  
Steel Substrate ◽  
Arc Spraying ◽  
Spray Parameters ◽  
Q235 Steel ◽  
Electrochemical Tests ◽  
Al Composite ◽  
Al Coating

High velocity arc spraying was used to prepare FeCrAl/Al composite coating on Q235 steel substrate by simultaneously spraying FeCrAl wire as the anode and Al wire as the cathode. The composite coating was sprayed with varying voltage and current to obtain optimum coating characteristics. FeCrAl coating was also prepared for comparison purposes. The surface microstructure of the coatings was characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The average microhardness of the coatings and the substrate was analyzed and compared. Corrosion resistance was investigated by means of electrochemical tests. The image results showed that a lamellar structure consisted of interwoven layers of FeCrAl and Al. Al and FeCr constituted the main phases with traces of oxides and AlFe intermetallic compounds. The average porosity was reduced and microhardness of the coatings was improved with increasing voltage and current. The FeCrAl/Al coating formed alternating layers of hard and ductile phases; the corrosion resistance of the coatings in the sodium chloride (NaCl) solution depended on the increase in Al content and spray parameters. The corrosion resistance tests indicated that FeCrAl/Al coating had a better corrosion resistance than the FeCrAl coating. FeCrAl/Al can be used to coat steel substrates and increase their corrosion resistance.

scholarly journals Influence of the resistive-pulse welding parameters of nickel super-alloys on selected properties of the connection

Mechanik ◽  
2017 ◽  
Vol 90 (11) ◽  
pp. 1060-1062
Author(s):  
Sławomir Spadło ◽  
Wojciech Depczyński ◽  
Piotr Młynarczyk ◽  
Tadeusz Gajewski ◽  
Jarosław Dąbrowa
Keyword(s):  
Optical Microscope ◽  
Mechanical Tests ◽  
Welding Parameters ◽  
Thin Sheets ◽  
Micro Hardness ◽  
Hastelloy X ◽  
Haynes 230 ◽  
Hardness Tester ◽  
Resistive Pulse ◽  
Pulse Welding

Microstructure and mechanical tests of welds of thin sheets made from nickel-based super-alloys (Haynes 230 and Hastelloy X) were presented. The welds were made using the resistive-pulse micro-welding method using the WS 7000S device. The micro-hardness of the joints was measured with a Matsuzawa Vickers MX 100 hardness tester at 100 G (0.98 N). Metallographic observations of the prepared micro-sections were performed using the Nikon Eclipse MA200 optical microscope at various magnifications. The metallographic microstructure studies were supplemented by linear analysis of the chemical composition, for which the OXFORD X-MAX electron microscope was applied.

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