• Journal of Electrochemical Science and Technology
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• v.11 no.2
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• pp.155-164
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• 2020

Here we report our preliminary results about nickel phosphide (Ni-P) electroless coating on the surface of cellulose paper (CP) and its feasibility as the anode for lithium (Li) batteries. In particular, CP can act as a flexible skeleton to maintain the mechanical structure, and the Ni-P film can play the roles of both the anode substrate and the active material in Li batteries. Ni-P films with different P contents were plated uniformly and compactly on the microfiber strands of CP. When they were tested as the anode for Li battery, their theoretical capacity per physical area was comparable to or higher than hypothetical pure graphite and P film electrodes having the same thickness. After the large irreversible capacity loss in the first charge/discharge process, the samples showed relatively reversible charge/discharge characteristics. All samples showed no separation of the plating layer and no detectable micro-cracks after cycling. When the charge cut-off voltage was adjusted, their capacity retention could be improved significantly. The electrochemical result was just about the same before and after mechanical bending with respect to the overall shape of voltage curve and capacity.

• Journal of the Korean institute of surface engineering
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• v.22 no.2
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• pp.101-108
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• 1989

Effects of Na+ ion on zeta potential of SiC and Al2O3 particles suspended in nikel sufate and nickel chloride solutions were investigated. various complexing agents for Ni2+ ion were added to electroless Ni composite bath and the effects of the complexing agents on zeta potential and codeposition of the particles from the baths were studied. It was confirmed that Na+ ion was absorbed on the particles bringing about the positive surface charge and thus they promoted the entrapment of the particles into the nickel deposit. On the basis of these results it was possible to deposit SiCc particle in nickel chloride electrolyte containing complex agent such as trisodium citrate+sodium succinate.

• Journal of Powder Materials
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• v.24 no.3
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• pp.242-247
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• 2017

In this study, the electroless nickel plating method has been investigated for the coating of Ni nanoparticles onto fine Al powder as promising energetic materials. The adsorption of nickel nanoparticles onto the surface of Al powders has been studied by varying various process parameters, namely, the amounts of reducing agent, complexing agent, and pH-controller. The size of nickel nanoparticles synthesized in the process has been optimized to approximately 200 nm and they have been adsorbed on the Al powder. TGA results clearly show that the temperature at which oxidation of Al mainly occurs is lowered as the amount of Ni nanoparticles on the Al surface increases. Furthermore, the Ni-plated Al powders prepared for all conditions show improved exothermic reaction due to the self-propagating high-temperature synthesis (SHS) between Ni and Al. Therefore, Al powders fully coated by Ni nanoparticles show the highest exothermic reactivity: this demonstrates the efficiency of Ni coating in improving the energetic properties of Al powders.

• Particle and aerosol research
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• v.10 no.4
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• pp.177-182
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• 2014

In this study, nickel-coated aluminum (Ni/Al) powders were synthesized for the utilization of energetic applications. Oxide materials present at the surface of Al powders of $45{\mu}m$ in averaged size were removed by using sodium hydroxide(NaOH) solution which is used for controlling pH. Nickel material is coated into the surface of oxide-removed Al powders by electroless-plating process. The microstructure of fabricated Ni/Al powders shows that nickel layers with a few hundreds nm were very homogeneously formed onto the surface of Al powders. The oxidation behavior of Ni/Al exihibit somewhat faster oxidation rate than that of pure Al with surface oxidation. Also, the higher exothermic reaction was observed from the Ni/Al powders. From the result of this, nickel coating is very promising method to obtain highly reactive and safe Al powders for energetic applications.

• Journal of the Korean institute of surface engineering
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• v.19 no.3
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• pp.83-91
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• 1986

Codeposited of boron nitride(BN) particle dispersed into electroless nickel-phosphours (Ni-P) and nickel-boron(Ni-B) platings were studied for the purpose of developing the wear resistance and lubricity. BN can be codeposited from electroless nickel plating bath with $NaH_2PO_2$ and $NaBH_4$ as the reducing agents. Most dispersolids were distributed uniformly in the Ni-P and Ni-B matrix. Abrasion loss decreased with increasing amount of codeposits and reached a constant value 2.4 percent by volume percent of BN particle. The wear resistance and the friction coefficient of the heat treated BN composite coatings were improved about three times than that of as-coatings. The BN composite coatings were more wear resistance than hard chromium. Ni-B-BN composite coatings showed lower wear resistance and friction coefficient than Ni-P-BN. The BN content of the deposite was found to be 2.4 v/o for these optium conditions.

• Journal of the Korean institute of surface engineering
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• v.22 no.1
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• pp.43-51
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• 1989

The characteristion of composite electroless Nikel palting on the condition of adding 3kinds ceramic dispersives, Al2O3, Si3O4 and artificial diamond powder were studied. Decreasing solution temperature for composite plating was required to depress the spontaneous decomposition caused by dispersive including enlargement of reaction surface. The rate of composite plating was faster than that of general electroless-Nickel plating without dispersive. this increasing tendency of plating rate was remarkable for the active catalysis, like diamond powder.

• Journal of the Korean institute of surface engineering
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• v.27 no.4
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• pp.193-206
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• 1994

A wear behavior of electroless (Ni-P-X, X: SiC, $Al_2O_3$, Diamond) composite coating layers, formed under various conditions on commerical grade low carbon steel, has been investigated using Taber abrasion tester and scanning electron microscope. Several factors, which are type of particles, co-deposited content, particle size, distribution of particles and heat-treatment, influenced the wear resistance. The wear resistance of the composited coating layers after heat-treatment at $400^{\circ}C$ for 1 hr was increased 70 times with diamond, 15 times with SiC and 8 times with $Al_2O_3$, compared with the electroless nickel plating layer without heat-treatment.

• Journal of the Microelectronics and Packaging Society
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• v.16 no.3
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• pp.11-17
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• 2009

The drop impact reliability comes to be important for evaluation of the life time of mobile electronic products such as cellular phone. The drop impact reliability of solder joint is generally affected by the kinds of pad and reflow number, therefore, the reliability evaluation is needed. Drop impact test proposed by JEDEC has been used as a standard method, however, which requires high cost and long time. The drop impact reliability can be indirectly evaluated by using high speed shear test of solder joints. Solder joints formed on 3 kinds of surface finishes OSP (Organic Solderability Preservation), ENIG (Electroless Nickel Immersion Gold) and ENEPIG (Electroless Nickel Electroless Palladium Immersion Gold) was investigated. The shear strength was analysed with the morphology change of intermetallic compound (IMC) layer according to reflow number. The layer thickness of IMC was increased with the increase of reflow number, which resulted in the decrease of the high speed shear strength and impact energy. The order of the high speed shear strength and impact energy was ENEPIG > ENIG > OSP after the 1st reflow, and ENEPIG > OSP > ENIG after 8th reflow.

• Korean Journal of Materials Research
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• v.24 no.11
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• pp.632-638
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• 2014

We investigated the effects of DMAB (Borane dimethylamine complex, C2H10BN) in electroless Ni-B film with addition of DMAB as reducing agent for electroless Ni plating. The electroless Ni-B films were formed by electroless plating of near neutral pH (pH 6.5 and pH 7) at $50^{\circ}C$. The electroless plated Ni-B films were coated on screen printed Ag pattern/PET (polyethylene terephthalate). According to the increase of DMAB (from 0 to 1 mole), the deposition rate and the grain size of electroless Ni-B film increased and the boron (B) content also increased. In crystallinity of electroless Ni-B films, an amorphization reaction was enhanced in the formation of Ni-B film with an increasing content of DMAB; the Ni-B film with < 1 B at.% had a weak fcc structure with a nano crystalline size, and the Ni-B films with > 5 B at.% had an amorphous structure. In addition, the Ni-B film was selectively grown on the printed Ag paste layer without damage to the PET surface. From this result, we concluded that formation of electroless Ni-B film is possible by a neutral process (~green process) at a low temperature of $50^{\circ}C$.

• Journal of the Korean institute of surface engineering
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• v.19 no.2
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• pp.31-43
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• 1986

The properties of the electroless nickel deposit mainly depends on the pH of the bath, the plating temperature, and the molar ratio of nickel to hypophosphite but they are also affected by its formulation and concentration of complexing and buffering agents. According to changeing the concentration of triethanolamine and boric acid, phosphorous contents, microsturcture, crystalline, hardness and wear resistance of deposits obtained from ammoniacal alkaline bath were investigated by EPMA, differential thermal analyser, X-ray diffractometer and wear tester. The results are as follows; (1) Increasing concentration of triethanolamine in the bath, the deposits is slightly inclined to increase its phosphorous content(3.7% P). (2) In the as-plated state, the deposits are not crystallized state but they are thermally unstable phase, and they are crystallized with precipitating $Ni_3P$ at 400$^{\circ}C$. (3) The deposit containing 2.3% P has higher hardness value in the as plated and heat treated state at below 300$^{\circ}C$ than those of 3.7% phosphorous deposit (1090Hk). But in the case of heat treating at 400$^{\circ}C$, the former has lower hardness value (1000Hk) than the latter and has remarkably Ni(III) orientation by heat treatment. (4) The 3.7% phosphorous deposit heat treated at 400$^{\circ}C$ has better wear resistance than hard chromium plating.