Influence of Heat-Treatment on High-Phosphorus Ni–P Plating Coating

2011 ◽  
Vol 337 ◽  
pp. 87-90 ◽  
Author(s):  
Xiao Juan Wu ◽  
Zheng Jun Liu ◽  
Guo De Li

The high-phosphorus electroless Ni–P plating coating with 11.64 at.% was prepared by electroless technology. By means of x-ray diffraction and scanning electron microscopy, the morphologies and phase structures of coating were analyzed. Furthermore, the mechanical properties of coating were studied by micro-hardness tester and universal friction-wear testing machine. The results reveal that, with increasing heat-treatment temperatures, the hardness and the wear resistance of the coating are enhanced increasingly. Treated by 1 hour at 500 oC, the hardness and the wear resistance both display a optimum value, i.e. 1004 HV and 1.5×10-3g, respectively. The thermal shock test suggests that between coating and matrix exist a perfect cohesion.

2011 ◽  
Vol 291-294 ◽  
pp. 129-132
Author(s):  
Xiao Juan Wu ◽  
Zheng Jun Liu ◽  
Guo De Li

The high-phosphorus electroless Ni–P plating was coated on the surface of stainless steel. Five parameters, which have much effect on coating quality, were chosen to optimize the high-phosphorus electroless Ni–P plating technology in L16(45) orthogonal test. By means of x-ray diffraction and scanning electron microscopy, the morphologies and phase structures of coating were analyzed. Furthermore, the mechanical properties of coating were studied by micro-hardness tester and universal friction-wear testing machine. The results reveal that the optimal technical parameters are as follows: 20 g•L-1 for NiSO4, 23 g•L-1 for NaH2PO2, 15 g•L-1 for C6H5O7Na3•2H2O, 8 g•L-1 for H2N-CH2-COOH, 10g•L-1 for CH3COONa, 7 g•L-1 for C4H6O4, with PH value of 4.6, which leads to perfect coating quality. Besides, the P content is 11.64 wt.%, i.e. a high-P coating. The micro-hardness of the coating is 550.67 HV and the wear loss, 4.7×10-3 g. The thermal shock test suggests that between coating and matrix exist a perfect cohesion, which is due to the homogenous and compact coating, with an amorphous structure, under the condition of the optimal technical parameters.


2009 ◽  
Vol 41 (2) ◽  
pp. 199-207 ◽  
Author(s):  
X. Dong ◽  
J. Hu ◽  
Z. Huang ◽  
H. Wang ◽  
R. Gao ◽  
...  

In this study, the boronized layers were formed on the surfaces of specimens with a composition of Fe-2 wt. % Cu-0.4 wt. % C by sintering and boronizing simultaneously, using a pack boronizing method. The processes were performed in the temperature range of 1050 - 1150 oC at a holding time of 4 hours in 97 % N2 and 3 % H2 atmosphere. Scanning electron microscopy examinations showed that the boronized layers formed on the surface of boronized and sintered specimens have a denticular morphology. The thicknesses of the boronized layers varied from 63 to 208 ?m depending on the processing temperature. The structures of the boronized layers were Fe2B and FeB confirmed by X-ray diffraction analysis. The microhardness values of boronized layers ranged from 1360 to 2066 HV0.3 much higher than that of substrate hardness which was about 186 HV0.3. Wear testing results showed that the wear resistance of the boronized and sintered specimens was significantly improved, resulting from increased surface microhardness.


2011 ◽  
Vol 399-401 ◽  
pp. 1838-1842
Author(s):  
You Bin Wang ◽  
Jian Min Zeng

The effects of Mn addition on the microstructure and hardness of 6061 aluminum alloy were studied by means of scanning electron microscope (SEM) , energy dispersive X-Ray Analysis (EDX), X-ray diffraction (XRD) and hardness tester in this work. The results shows that rod and fishbone AlSiFeMn phase will be formed in the alloy with Mn addition in 6061 aluminium alloy, and the AlSiFeMn phase increases with the increasing of Mn content . By the mean of XRD, the Al4.07 Mn Si0.74 phase is found in the 6061 aluminium alloy from 0.7% to 1.5% Mn. The hardness increases with the increasing of Mn contents both for as-cast and for T6 heat treatment. However, the hardness growth rate for as-cast is much more than that for T6 heat treatment at the same Mn addition in the 6061 alloy. Mn has a little effect on the hardness for T6 heat treatment in 6061 alloy.


Author(s):  
V. Agafii ◽  
V. Mihailov ◽  
N. Kazak ◽  
G. Volodina ◽  
C. Cracan

The article presents the results of wear testing of stainless steel Cr18Ni10Тi treated with electrodes made of refractory metals and graphite by the method of electric-spark alloying. It was established that all electrospark coatings had a higher wear resistance than the Cr18Ni10Ti uncoated steel. Wear resistance of coatings was increased in the direction Mo + GraphiteTi + Ni W + Graphite Ti + Al + Graphite. X-ray diffraction analysis showed that molybdenum, tungsten, titanium carbides and other solid materials such as titanium nitride and nickel-titanium intermetallide are formed on the doped steel surfaces, which increased microhardness from 4.9 to 8 times and wear resistance from 1.63 to 29 times.


2014 ◽  
Vol 1082 ◽  
pp. 480-483
Author(s):  
Zhen Ting Wang ◽  
Shi Kui Zhu ◽  
Fan Feng ◽  
Hao Ran Cheng ◽  
Zhi Jie Kang ◽  
...  

Nanostructure WC composite coatings were prepared on surface of Q235 steel by argon arc cladding injection using microstructure WC feeding which were prepared by nanostructure WC powder. The microstructure of the coating were analyzed by scanning electron microscopy (SEM). Phase of the coating were analyzed by energy dispersive spectrometer and X-Ray diffract meter, moreover, microhardness and wear resistance were texted by Microhardness tester (HVST-1000) and friction wear testing machine (MMS-2A). The results show that the combination of coating and substrate is metallurgical bonding. and no Pores and cracks were founded in bonding area. aggregated nanostructure WC particles and nanostructure WC particles uniformly distributed in the coating. The maximum hardness of the coating is 1461 HV. Compared with the Q235 steel, the wear resistance of the coating increased about 15 times.


2012 ◽  
Vol 538-541 ◽  
pp. 235-238 ◽  
Author(s):  
Ren Guo Song ◽  
Pu Hong Tang ◽  
Chao Wang ◽  
Guo Lu

Al2O3 and Al2O3-40wt.%TiO2 ceramic coatings on H13 hot-worked die steel have been prepared by plasma spraying, and then the microstructure, micro-hardness as well as wear resistance of the prepared coatings have been investigated by means of x-ray diffraction (XRD), scanning electron microscope (SEM), Vickers hardness tester and ball-on-disk high temperature tribometer. The results showed that the plasma sprayed ceramic coatings are of higher hardness and wear resistance than H13 hot-worked die steel.


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.


2011 ◽  
Vol 189-193 ◽  
pp. 373-376 ◽  
Author(s):  
Huai Yao ◽  
Guang Lin Zhu ◽  
Meng Du

The ternary Ni-W-P alloy coatings were deposited on the surface of Q235 steel using Chemical deposition. The microstructure, phase analysis, plating velocity and hardness were investigated with scanning electron microscope, X-ray diffraction technique and Vickers hardness tester. The results showed that the plating rate had been increased firstly, and then decreased with the increment of sodium citrate concentration in the range of 20-80g/L, the maximum plating velocity was 9.14μm/h. The hardness of Ni-W-P plating increased first and then decreased with the increment of sodium citrate concentration, the maximum hardness was 643HV when the concentration of sodium citrate was 40g/L. When the concentration of sodium citrate was 40g/L, the substrate was completely covered by Ni-W-P plating, the surface was composed of uniform crystalline grains, and had no obvious defects and presented amorphous. The coating and substrate were relatively strong, the coating had no the phenomena of fall off and crackle in the bending and files tests when the concentration of sodium citrate was 40g/L and 50g/L respectively.


2013 ◽  
Vol 750-752 ◽  
pp. 2052-2056 ◽  
Author(s):  
Lu Miao ◽  
Ya Nan Wang ◽  
Yan Hui Li

By vacuum fusion sintering technique made different CeO2 addition Ni-WC composite coatings on 45 steel. Hardness, wear resistance property and corrosion resistance property of the Rare-earth Ni-WC composite coatings were measured and analyzed by Rockwell hardness tester,micro-hardness tester, friction wear testing machine and Salt spray corrosion box. The results showed that:The CeO2 content comes up to 0.75% of the coatings` hardness, wear resistance and corrosion resistance property better than those of other coatings.


2017 ◽  
Vol 65 (2) ◽  
pp. 149-154 ◽  
Author(s):  
C. F. John ◽  
R. C. Paul ◽  
S. C. E. Singh ◽  
T. Ramkumar

Abstract High-energy mechanical alloying method was used to prepare Al-12Si-xZrC (x = 0, 5, 10, 15 wt. %) nanocomposites. Cylindrical preforms were prepared with an initial preform density of 89% by using a suitable die and punch assembly. The preforms were sintered in a muffle furnace with an inert gas atmosphere at a temperature of 550°C, followed by cooling until room temperature has been attained. Scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques were used to characterize the composites. Pin-on-disc wear testing machine was used to determine the tribological properties of the prepared composites. The results show that the wear loss reduced with increasing the reinforcement content and coefficient of friction increases gradually.


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