Tribological Behavior and Corrosion Resistance of Electroless Ni-B-W Coatings

2017 ◽  
Vol 05 (03) ◽  
pp. 1750010 ◽  
Author(s):  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo

The present study considers the tribological behavior and corrosion resistance of electroless Ni-B-W coatings deposited on AISI 1040 steel substrates. Coating is characterized using scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffraction technique. In as-deposited condition, coatings are found to be amorphous. On heat treatment, precipitation of crystalline Ni (1 1 1) and its borides take place. For as-deposited coating, the microhardness is obtained as [Formula: see text]759[Formula: see text]HV[Formula: see text] which increases to [Formula: see text]1181[Formula: see text]HV[Formula: see text] and [Formula: see text]1098[Formula: see text]HV[Formula: see text] when heat treated at 350[Formula: see text]C and 450[Formula: see text]C, respectively. Incorporation of W in Ni-B coating results in an increase of hardness by 89[Formula: see text]HV[Formula: see text] in as-deposited condition. Heat treatment also results in increase in crystallite size of Ni (1 1 1). Wear rate and coefficient of friction (COF) of the coatings are evaluated on a pin-on-disc setup under both dry and lubricated sliding conditions. Wear resistance is observed to improve on heat treatment with an increase in crystallite size while COF deteriorates. However, in as-deposited condition, wear rate and COF of Ni-B-W coatings improve by [Formula: see text]5 and [Formula: see text]3 times, respectively, compared with Ni-B coatings. Wear and friction performance of the coatings are enhanced under lubrication due to the columnar structure of the coatings that retain lubricants. Corrosion resistance of Ni-B-W coating in 3.5% NaCl solution gets improved on heat treatment.

2017 ◽  
Vol 24 (Supp01) ◽  
pp. 1850014 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO

The present work investigates the effects of heat treatment on friction and wear behavior of electroless Ni–B coatings at elevated temperatures. Coating is deposited on AISI 1040 steel specimens and subjected to heat treatments at 350[Formula: see text]C, 400[Formula: see text]C and 450[Formula: see text]C. Coating characterization is done using scanning electron microscope, energy dispersive X-Ray analysis and X-Ray diffraction analysis. Improvement in microhardness is observed for the heat treated deposits. Further, the effect of heat treatment on the tribological behavior of the coatings at room temperature, 100[Formula: see text]C, 300[Formula: see text]C and 500[Formula: see text]C are analyzed on a pin-on-disc setup. Heat treatment at 350[Formula: see text]C causes a significant improvement in the tribological behavior at elevated temperatures. Higher heat treatment temperatures cause deterioration in the wear resistance and coefficient of friction. The wear mechanism at 100[Formula: see text]C is observed to be predominantly adhesive along with abrasion. While at 300[Formula: see text]C, abrasive wear is seen to be the governing wear phenomenon. Formation of mechanically mixed layers is noticed at both the test temperatures of 100[Formula: see text]C and 300[Formula: see text]C for the coatings heat treated at 400[Formula: see text]C and 450[Formula: see text]C test temperature. The predominant wear mechanisms at 500[Formula: see text]C are abrasive and fatigue for as-deposited and heat treated coatings, respectively.


Author(s):  
Santanu Duari ◽  
Arkadeb Mukhopadhyay ◽  
Tapan Kumar Barman ◽  
Prasanta Sahoo

This paper presents an experimental study on tribological behavior of electroless Ni-B coating under lubricated condition based on Taguchi’s method. Mild steel specimens are used as the substrate material for the deposition of Ni-B coating and the thickness of the deposits is found to be around 35 μm. Based on Taguchi’s L27 orthogonal array of experiments, the wear tests are done on a pin-on-disc type tribotester This experiment is carried out by utilizing the combination of process parameters of the tribotester like normal load, sliding speed and duration of sliding. The analysis of the experimental data is carried out with the help of MINITAB® software package. It is seen that the normal load is the most significant factor followed by sliding time at 99% confidence level. The surface morphology, composition and compound analysis of the coatings are done by means of scanning electron microscope, energy dispersed X-ray micro-analyzer and X-ray diffraction analyzer respectively. Finally, a confirmation test is carried out to validate the analysis.


2017 ◽  
Vol 2 (2) ◽  
pp. 118 ◽  
Author(s):  
Ahmadi Jaya Permana ◽  
Dian Wulandari ◽  
Hartati Hartati ◽  
Harsasi Setyawati ◽  
Mochammad Zakki Fahmi

 Zinc oxide (ZnO) is a semiconductor material that widely used in various applications due to its unique properties. Synthesis of ZnO by solvothermal method has been conducted with controlled pH values. The variations of pH value were 10, 11 and 12 by adjusting NaOH content. Crystall structure of the synthesis products after heat treatment at 110oC and 600oC has characterised by X-ray Diffratometer (XRD). Crystallite size of ZnO was measured by Scherrer equation. Crystall phase of ZnO has been observed on all pH value variations at 110 oC with 22,98-37,06 nm of crystallite size, whereas ZnO has been observed on all pH value variations at 600 oC with 41,39-71,77 nm of crystallite size.Keywords: ZnO, pH values, crystallite size, solvothermal


2018 ◽  
Vol 25 (08) ◽  
pp. 1950023 ◽  
Author(s):  
ARKADEB MUKHOPADHYAY ◽  
TAPAN KUMAR BARMAN ◽  
PRASANTA SAHOO

The present work reports the deposition of a quaternary Ni-B-W-Mo coating on AISI 1040 medium carbon steel and its characterization. Quaternary deposits are obtained by suitably modifying existing electroless Ni-B bath. Composition of the as-deposited coating is analyzed by energy dispersive X-ray spectroscopy. The structural aspects of the as-deposited and coatings heat treated at 300[Formula: see text]C, 350[Formula: see text]C, 400[Formula: see text]C, 450[Formula: see text]C and 500[Formula: see text]C are determined using X-ray diffraction technique. Surface of the as-deposited and heat-treated coatings is examined using a scanning electron microscope. Very high W deposition could be observed when sodium molybdate is present in the borohydride-based bath along with sodium tungstate. The coatings in their as-deposited condition are amorphous while crystallization takes place on heat treatment. A nodulated surface morphology of the deposits is also observed. Vickers’ microhardness and crystallite size measurement reveal inclusion of W and Mo results in enhanced thermal stability of the coatings. Solid solution strengthening of the electroless coatings by W and Mo is also observed. The applicability of kinetic strength theory to the hardening of the coatings on heat treatment is also investigated. Corrosion resistance of Ni-B-W-Mo coatings and effect of heat treatment on the same are also determined by electrochemical techniques.


Author(s):  
Manu Sam ◽  
N Radhika ◽  
Katru Pavan Sai

LM25 aluminum alloy reinforced with 10 wt% of TiB2, WC, and ZrO2 were squeeze cast to investigate the effect of T6 heat treatment on tribo-mechanical properties. Among all, WC-reinforced composite achieved superior mechanical properties at the aging time of 8 h. Microstructural examination performed on all composites and alloy concluded that the presence of WC in T6 LM25 caused reduction of α-Al dendrite size, exhibiting superior properties for this composite. X-ray diffraction analysis conducted on alloy and WC-reinforced superior composite revealed formations of phases, which improved their mechanical properties. Energy-dispersive X-ray spectroscopy analysis quantified the actual intensity of WC presence in the superior composite along with its other constituents. Response surface methodology model developed for wear test of the superior composite involves parametric range like applied load (10–50 N), sliding velocity (1–4 m/s), and sliding distance (500–2500 m). Analysis of variance along with regression analysis proved that, statistical analytical model developed good relationship between the actual wear rate and process parameters. Response surface plots represented the linearly increasing wear trend with respect to load and sliding distance. Wear rate dropped initially and raised later on along with velocity. Scanning electron microscopy exhibited the surface deformation prevailing on the composite surface at high load.


2016 ◽  
Vol 844 ◽  
pp. 133-140 ◽  
Author(s):  
Mariya R. Komissarova ◽  
Ilia G. Dyakov ◽  
Yurii P. Gladii

Microhardness, friction coefficient, and wear rate of carburized titanium alloy VT 20 are considered. An X-ray diffractometer, a scanning electron microscopy (SEM) used to characterize the phase composition of the modified layer and its surface morphology. A pin-on-disc tribometer was occupied to evaluate wear behavior of the treated titanium alloys. It is established that the friction coefficient decreases from 0.46 (untreated sample) to 0.15 for the sample carburized at 750 °C during 5 min. Therefore, the anode carburizing of titanium alloys results in the reducing of the wear rate by 2 orders.


2012 ◽  
Vol 184-185 ◽  
pp. 1175-1180
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Bi Xue Yang

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.


Silicon ◽  
2017 ◽  
Vol 10 (3) ◽  
pp. 1203-1215 ◽  
Author(s):  
Arkadeb Mukhopadhyay ◽  
Tapan Kr. Barman ◽  
Prasanta Sahoo

2011 ◽  
Vol 306-307 ◽  
pp. 901-906 ◽  
Author(s):  
Huan Ming Chen ◽  
Ya Hong Gao ◽  
Qiong Lv ◽  
Dong Yang ◽  
Xin Xin Lin

The Ni-P-W/nano-Al2O3composite coatings were deposited on the surface of sintered NdFeB permanent magnet by electroless plating method. The morphology and the phases of Ni-P-W/nano-Al2O3composite coatings were investigated using scanning electron microscopy and X-ray diffraction respectively. The hardness and the corrosion resistance of the composite coatings were also tested. The results indicated that the composite coatings morphology appears closely nodules morphology, and the microhardness increases with increasing incorporation of Al2O3ratio. Compared with NdFeB magnet and Ni-P-W alloy coatings, the corrosion resistance of the composite coatings was superior to that of the NdFeB magnet and the alloy coating obviously.


2011 ◽  
Vol 189-193 ◽  
pp. 1096-1099
Author(s):  
Xi Ran Wang ◽  
Hui Lu ◽  
Ying Wei Zhang ◽  
Xin Gang Hu ◽  
Jing Wu

In this work, the effect of plating temperature on the electroless plating rate and the properties of the electroless Ni-Cu-P deposits was studied. The corrosion resistance, hardness, surface morphology and components of the coating were studied by using electrochemical workstation, digital micro-hardness SEM and EDS. The results show that the optimum plating temperature is 75°C. The deposition rate, hardness and corrosion resistance are all good when the optimal temperature is 75°C. The adhesion between the deposits and the matrix is better. The deposits is smooth and uniformity, smooth by SEM. The deposit contains Ni 77.80%, Cu 7.68%, P 14.52% by the analyses of energy disperse X-ray.


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