Improvement on Hardness of 6061 Al Alloy Using an Electroless Ni-P Coating

2010 ◽  
Vol 26-28 ◽  
pp. 293-296 ◽  
Author(s):  
Wen Feng Qin ◽  
Jiang Long ◽  
Feng Liu
Keyword(s):  
Surface Morphology ◽  
Sodium Hypophosphite ◽  
Al Alloy ◽  
Plating Bath ◽  
Nodular Structure ◽  
P Content ◽  
Scanning Electron Microcopy ◽  
Alloy Plating ◽  
6061 Al Alloy ◽  
Electroless Ni

The surface morphology and hardness of electroless Ni–P alloy plating on 6061 aluminum alloys substrate in an alkaline plating bath with sodium hypophosphite as reducing agent were investigated. The effects of bath pH on the plating rate, compositions and surface morphology of theelectroless Ni-P deposits were studied. The results showed the deposition rate of the electroless Ni–P deposits increased with the rise of the bath pH, while the P content decreased. Scanning electron microcopy (SEM) of the deposits showed nodular structure for the deposits. Hardness data of the Ni-P coatings indicated that electroless Ni–P plating could obviously improve the hardness of 6061aluminum alloy.

Formation and Structural Characterization of Electroless Ni-B-P Ternary Alloy Coatings

2014 ◽  
Vol 592-594 ◽  
pp. 385-390 ◽  
Author(s):  
P.G. Venkatakrishnan ◽  
S.S. Mohamed Nazirudeen ◽  
T.S.N. Sankara Narayanan
Keyword(s):  
Electroless Plating ◽  
Morphological Characteristics ◽  
Reducing Agents ◽  
Sodium Hypophosphite ◽  
Electron Microscopic ◽  
Plating Bath ◽  
Peak Broadening ◽  
Chloride Hexahydrate ◽  
Electroless Ni

The aim of the present investigation is to study the formation of electroless Ni-B-P alloy coatings and structural and morphological characterization of various coatings with different boron and phosphorous content. An alkaline plating bath with nickel chloride hexahydrate as the source of nickel ions and sodium borohydride and sodium hypophosphite as reducing agents were used for the formation of electroless Ni-B-P alloy coatings. The influence of changes in the concentrations of the reducing agents in the electroless plating bath on the chemical composition, structural and morphological characteristics of the coatings were studied. Scanning electron microscopic studies revealed that the surface morphology of Ni-B-P alloy coatings changed from corn cob-like structure to cauliflower-like structure with increasing borohydride concentration in electroless plating bath, whereas increase in hypophosphite concentration favoured sideway growth, thereby decreased the surface roughness of the Ni-B-P alloy coatings. The peak broadening in the X-Ray Diffraction profiles indicates the large reduction in the crystallite size of the electroless Ni-B-P alloy coatings with increasing boron content in the coating (i.e. for higher borohydride concentration in the plating bath).

MORPHOLOGY, THERMAL STABILITY, AND SOLDERABILITY OF ELECTROLESS NICKEL–PHOSPHORUS PLATING LAYER

2007 ◽  
Vol 14 (04) ◽  
pp. 827-832 ◽  
Author(s):  
JEONG-WON YOON ◽  
HYUN-SUK CHUN ◽  
HAN-BYUL KANG ◽  
MIN-HO PARK ◽  
CHEOL-WOONG YANG ◽  
...  
Keyword(s):  
Surface Composition ◽  
Electroless Nickel ◽  
Sodium Hypophosphite ◽  
X Ray Diffraction ◽  
Plating Bath ◽  
Heat Treated ◽  
P Content ◽  
The Individual ◽  
Wetting Force ◽  
Treated Layer

We studied the growth kinetics and characteristics of electroless nickel–phosphorus (EN–P) deposition layer on Cu substrate in an acid plating bath with sodium hypophosphite as the reducing agent. The individual nodules of the EN–P layer increased in size but decreased in number with increasing plating time and pH, i.e. the root-mean-square (RMS) roughness of the EN deposit decreased. In addition, the plating rate of the EN layer increased with increasing plating bath pH. X-ray diffraction (XRD) analyses revealed that the as-plated deposit was in an amorphous phase, while the heat-treated layer was composed of crystallized Ni and Ni 3 P compound. The solderability of the EN layer increased with decreasing P content. In addition, the wetting force increased with increasing surface roughness. The present study clearly showed that the solderability behavior of the EN layer is affected by both surface composition ( P content) and morphology.

TEMPERATURE DEPENDENCE OF ELECTROLESS Ni–P DEPOSITION ON POLYESTER FABRIC

2008 ◽  
Vol 15 (05) ◽  
pp. 587-593 ◽  
Author(s):  
R. H. GUO ◽  
S. Q. JIANG ◽  
C. W. M. YUEN ◽  
M. C. F. NG
Keyword(s):  
Electromagnetic Interference ◽  
Surface Resistance ◽  
Polyester Fabric ◽  
Amorphous Structure ◽  
Shielding Effectiveness ◽  
Plating Bath ◽  
P Content ◽  
Electromagnetic Interference Shielding Effectiveness ◽  
Electroless Ni ◽  
Emi Se

The effects of plating temperature on the plating rate, P content, surface morphology, and electrical resistance of the electroless Ni–P deposits were studied. The results showed that the deposition rate of the Ni–P deposit and P content of the Ni–P layer increased with the rise of temperature of the plating bath. Scanning electron microscopy of the Ni–P deposits showed a nodule structure. The Ni–P plating layers had an amorphous structure and surface resistance of the layer decreased with the rise of temperature. In addition, the electromagnetic interference shielding effectiveness (EMI SE) of electroless Ni–P plated polyester fabric was also investigated. The result indicated that EMI SE of Ni–P plated polyester fabric was close to 45–50 dB when the surface resistance was 0.63 Ω/□.

Study on Ni-P-Nanometer Diamond Composite Electroless Plating for 2A12 Aluminum Alloy

2012 ◽  
Vol 472-475 ◽  
pp. 2926-2929 ◽  
Author(s):  
Gang Yi Cai ◽  
Bing Yi Yan ◽  
Xue Feng Shi
Keyword(s):  
Aluminum Alloy ◽  
Adhesion Strength ◽  
Deposition Rate ◽  
Sodium Acetate ◽  
Orthogonal Design ◽  
Nickel Sulfate ◽  
Sodium Hypophosphite ◽  
Plating Bath ◽  
Diamond Composite ◽  
Electroless Ni

On the basis of electroless Ni-P plating, the technique of electroless Ni-P-nanometer diamond composite plating for 2A12 aluminum alloy was studied. The table of L9 (34) of orthogonal design was adopted in the experiment. The optimal formulation of plating bath for 2A12 aluminum alloy was determined. The effect of bath composition on deposition rate and adhesion strength was studied. The results show that the order of marked factors on deposition rate from large to small is nanometer diamond, sodium acetate, nickel sulfate hexahydrate and sodium hypophosphite in turn, while for adhesion strength is nanometer diamond, sodium acetate, sodium hypophosphite and nickel sulfate hexahydrate. The optimal plating formulation are consisted of nanometer diamond (2g/L), NiSO4•6H2O (30g/L), NaH2PO2•H2O (30g/L) and CH3COONa (15g/L), which is operated at 80~85°C, pH (4.5). The microstructure of coating plated with optimal process is cellular structure, which is homogeneous, compact and good brightness, and its deposition rate is 17.0μm/h.

ELECTROLESS QUATERNARY NI-CU-CO-P ALLOY DEPOSITION MECHANISM IN ACIDIC BATH USING CYCLIC VOLTAMMETRY MEASUREMENT

2017 ◽  
Vol 79 (5-2) ◽  
Author(s):  
Mohd Nor Azran ◽  
Muhamad Khaizaki ◽  
Muhammad Alif ◽  
Muhammad Zaimi ◽  
Mohd Asyadi ‘Azam ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Nickel Alloy ◽  
Oxidation Potential ◽  
Plating Bath ◽  
Alloy Deposition ◽  
Cyclic Voltammetry Measurement ◽  
P Content ◽  
Ni Alloy ◽  
Electroless Ni ◽  
Acidic Bath

Quaternary nickel alloy of Ni-Co-Cu-P has been successfully deposit on Fe substrate for corrosion resistant material. However, the reaction mechanism of quaternary nickel alloy deposition is less known and requires investigation. In this study, using similar bath component is used to produce electroless Ni-Cu-Co-P alloy. Cyclic voltammetry (CV) study is done in various plating bath component at bath pH 4.50, 4.75 and 5.00. A coating of Ni-Cu-Co-P alloy was deposited on a Fe substrate to evaluate surface morphology and composition. From CV results, higher bath pH, increases the [H2PO2-] oxidation peak and shifted the oxidation potential towards less noble potential. The reduction potential of the Ni alloy moved to noble potential, hence, elevate deposition rate from 3.95 to 5.95 mm/hr. The Ni-Cu-Co-P alloy composition on Fe substrate in descending manner is Ni (68.55 – 82.09 wt%), Cu (14.11 – 27.80 wt%) and Co (1.32 - 1.52wt%). The P content remained lower than 3.00 wt%. Hence, Co act as reaction inhibitor, while Cu act as both reaction accelerator and stabilizer.

Effects of Surfactant Agent and PTFE Content on Surface Morphology and Microstructure of Ni-P-PTFE Composite Coating

2012 ◽  
Vol 625 ◽  
pp. 198-201
Author(s):  
Chuan Qi Fu ◽  
Xu He ◽  
Zhou Wang
Keyword(s):  
Surface Morphology ◽  
Composite Coating ◽  
Surfactant Concentration ◽  
Composite Coatings ◽  
Ultrasonic Frequency ◽  
Plating Bath ◽  
X Ray ◽  
Ptfe Composite ◽  
Electroless Ni ◽  
Scanning Electron

Effects of surfactant, PTFE concentration in plating bath on surface morphology and the microstructure of electroless Ni-P-PTFE composite coatings were investigated in this study. The dependence of microstructure and distribution of PTFE particles in composite coatings upon surfactant agent and PTFE content in the plating bath were reported. Also, effects of ultrasonic frequencies on PTFE content in the coatings were discussed. The surface morphology and microstructure of the composite coatings were analyzed using scanning electron microscope (SEM) and X-ray dialysis (XRD), respectively. The results obtained are indicating that surfactant and PTFE concentration in the plating bath have a great impact on PTFE content in the coatings, the population of PTFE in the coatings proved to increase with increasing surfactant concentration properly. In addition, ultrasonic frequency could change the PTFE content in the coating. The composite coating shows different surface morphology and microstructure in various surfactant concentrations, PTFE concentrations and ultrasonic frequencies.

Effects of the Duration of Potentiostatic Anodizing on the Corrosion Resistance and Surface Morphology of Films Formed on Mg-Al Alloys

2005 ◽  
Vol 486-487 ◽  
pp. 125-128 ◽  
Author(s):  
Seong Jong Kim ◽  
Seok Ki Jang ◽  
Jeong Il Kim
Keyword(s):  
Corrosion Resistance ◽  
Surface Morphology ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Film ◽  
Al Alloy ◽  
Active Dissolution ◽  
Dissolution Reaction ◽  
Alloy Az91 ◽  
Morphology Of Films

The effects of the duration of potentiostatic anodizing on the corrosion resistance and surface morphology of anodic oxide films formed on Mg-Al alloy (AZ91) in 1 M NaOH were investigated. With the formation of an anodic film, the current density decreased gradually, started to stabilize at 300 s, and was relatively constant at 600 s. These results may be related to the increased time for catalysis of the active dissolution reaction, which not only enlarges the area covered by the anodic film, but also produces a more coherent, thicker film. The reference corrosion potentials of the anodic oxide film for AZ91 shifted in the noble direction with time. In general, the corrosion resistance characteristics were improved with anodizing time.

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