Study On The Preparation And Performance Of Graphene/Ni

Nanostructured materials have a series of excellent properties becauseof distinctive structural features, which gained considerable interest allover the world. In the study of a variety of nanocrystalline material,nanocrystalline nickel and its composite materials is one of theimportant direction of research, mainly concentrated in theelectrodeposition process, structure, mechanical properties anddeformation mechanism, etc. However, the relationship between thecorrosion resistance and nano structure is relatively complex, corrosiveenvironment, grain size, structure have different influence, especiallynanocrystalline nickel thermal stability directly associated with theproperties and applications of materials. Nickel-based composites due toits high strength, excellent corrosion resistance and abrasion resistanceare widely used in the field of automobile and aviation. Usually adoptfiber and SiC particles as the second phase particles to improve itsmechanical properties, thermal stability, etc. Graphene as a second phaseparticles are expected to further improve the mechanical properties suchas the hardness, strength and corrosion resistance, wear resistance.Direct current deposition is the preparation of nanocrystalline nickeland graphene/nickel composite method of an effective and economic.Inthis paper, a direct current deposition preparation of nanocrystallinenickel and graphene/nickel base materials, analysis the stability of thenanocrystalline nickel after annealing, and study its corrosion resistancein different corrosion medium, and this paper makes a research on thecurrent density, content of graphene graphene/nickel-based composites microhardness, wear resistance, corrosion resistance, the influence law oftensile properties, and discusses the introduction of graphene on thethermal stability of nanocrystalline nickel. The study found that:(1) Thegrain size of nanocrystalline nickel initial is9.727nm, after200℃and300℃annealing treatment, the grain size is12.563nm and19.246nm,respectively, which show that the effect of annealing at200℃on grainsize is not big, mainly had the effect on stress relief, and annealing at300℃, in addition to eliminate internal stress, also can improve thedensity of material;(2) The corrosion resistance of electrodepositionnanocrystalline nickel in NaCl and NaOH liquid performance is different,Cl-on the corrosion of nanocrystalline nickel was much higher than thatof OH-corrosion; Low temperature annealing treatment is beneficial toimprove high concentration of NaCl and NaOH liquid corrosionresistance;(3) After200℃﹑300℃annealing, due to the elimination ofinternal stress and the increase of the density, the corrosion resistance ofelectrodeposition nanocrystalline nickel in NaCl solution is improved.Compared with NaCl solution, annealing treatment for electrodepositionof nanocrystalline nickel in NaOH etching liquid is not sensitive tocorrosion.For graphene/nickel composite materials, draws the followingconclusions:(1) Graphene/nickel composite material was prepared bydirect current deposition. Raman prove that GO sheets had been reducedduring the electrodeposition process.(2) The introduction of the graphenemake hardness, wear resistance, corrosion resistance of graphene/nickelcomposite material are improved, and with the concentration of GOincreased to0.15from0.01g/l, the hardness and wear resistance has a tendency to increase; The effects of current density on hardness, wearresistance of pure nickel and composite material are small;(3)Graphene/nickel composite microhardness after annealing treatment, withthe increase of annealing temperature, hardness drop of the amplitude isreduced, to improve the temperature needed for the same hardness, showsthat the introduction of graphene inhibits the abnormal grain growth ofnanocrystalline nickel, improve the thermal stability.