Effect of nickel-plated graphite on microstructure and properties of matrix for Fe-based diamond tools

Nickel-plated graphite particles and unmodified graphite particles with different contents were added to the Fe-based diamond composites.The basic properties of those specimens were measured,including relative density,hardness,bending strength,abrasion ratio and holding force coefficient.And also,SEM,XRD and EDS were used to carry out microstructure characterization,phase analysis and element distribution of these specimens.The results show that nickel plating effectively improves the surface wettability of graphite particles.And it is determined that an element diffusion zone is formed on the transition interface between the nickel-plated graphite and the matrix materials,effectively enhancing the interfacial bonding strength.Also,the pores and cracks in the matrix generated by adding the graphite particles are reduced after nickel plating.Thus,the loss of basic properties of the specimens is restrained.But it is found the higher the graphite content is,the weaker the positive effect of nickel plating is.In addition,it is revealed that nickel plating plays a conducive part in the formation of graphite lubricants on the working surface,and nickel-plated graphites can slow down the thermal corrosion of the diamond particles inside the high-temperature sintered specimens.

Sulfide-Based Nickel-Plated Fabrics for Foldable Quasi-Solid-State Supercapacitors

Smart wearable market is burgeoning,and flexible energy storage is crucial to cope with its development.The commonly-used metal-based current collectors are heavy with limited flexibility.Other carbon-based current collectors are expensive and fragile.Moreover,the poor interface between active material and current collector leads to unsatisfactory stability.Herein,these two issues are attempted to be solved by using cheap and lightweight polyester-based fabrics as well as in-situ growth.A deposited thin layer of nickel on the fabrics not only enhances the conductivity,but also serves as the sacrificial precursor for the growth of active materials.Thus,intimate contact is secured via chemical bonding.The electrode with ternary(metalinorganic-organic)component shows excellent electrochemical performance.Namely,high areal capacity is realized(2.2 C cm^(-2)at 2 mA cm^(-2)),which is far superior to its rigid nickel-foam-based counterpart.Furthermore,an allsolid-state supercapacitor device was assembled.The device provides an areal capacity of 2.03 C cm^(-2)at the current density of 2 mA cm^(-2).It realizes an energy density of 0.45 mWh cm^(-2)when the power density is 1.6 mW cm^(-2).This work offers a feasible and cost-efficient way for fabricating electrode materials with excellent performance for portable supercapacitors.

Reclaim nickel and remove organics from the spent electroless nickel-plating bath by electrolysis

Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.

Analysis of the Phenomena of Diamond Synthesis by Seeding with Diamond

Synthesizing diamond single crystal by diamond seed particles which were electroplated with nickel film as catalyst under high pressure and high temperature （HPHT） was described. The microstructure of nickel film after synthesis and morphology of grown diamond were investigated by means of X-ray diffraction （XRD） and scanning electron microscopy （SEM）, respectively. The phase structure in nickel film were graphite, NiC, Ni, and diamond structure hadn＇t been found. A lot of recrystallized graphite pits appear in interface between the inner surface of nickel film and the surface diamond. It is shown that the new-grown diamond was developed epitaxially on the crystal planes of seeds. Also, the new-grown diamond grew by two-dimensional nucleation and by a layer growth mechanism. The growth process of crystal was microaggregate→step→expansion→new crystal layers, and the flat growth interface transformed into a cellular interface at the same time.

STUDY ON THE SURFACE OF TITANIUM CARBIDE PARTICLE PACKAGED NICKEL

Two kinds of packaged processes by nickel on the surface of titanium carbide particle are studied in this work. One is the chemical nickel-plating, the other is the organometallic compound decomposition. The composition, structure and morphology of the packaged powder were analyzed with XRD, DAT/TGA, SEM, EPMA etc. It has been shown that nickel was even dispersed on the surface of titanium carbide particle by the. two kinds of processes, deposited nickel exists as spherical particles of about 0.1 μm in diameter. The merits and demerits of the two kinds of processes have been compared, the organometallic copmound decomposition among them is a kind of hopeful method, which is not used by other researchers.

Corrosion Behavior of Different Steel Substrates Coupled With Conductive Polymer Under Different Serving Conditions

The corrosion behaviors of stainless steel and nickel plated carbon steel coupled with conductive polymer were investigated in both hot humid environment and simulated marine environment. The corrosion currents of dif-ferent steel substrates and conductive polymer in simulated marine environment at room temperature were measured. The corrosion surfaces of different steel couples were observed under a scanning electron microscope （SEM） and chemical compositions were examined by energy dispersive spectrum （EDS） analysis. The corrosion mechanism was discussed. The results showed that the stability of both stainless steel and nickel-plated carbon steel in hot humid en- vironment was excellent and no corrosion happened in the blank test for 360 h while slight corrosion existed in the contact area of coupled steel substrates. In simulated marine environment, the corrosion current of the stainless steel was lower than 100 μA and some directional rod-like particles formed on the surface of the stainless steel, which are mainly caused by oxidative corrosion among different phases. The corrosion current of the nickel-plated carbon steel couples was much greater than that of stainless steel couples and nickel plate cracking resulted in the corrosion of the internal iron because the coated nickel layer was not dense enough.