Research And Performance Of The Coating Of High Temperature Resistance Ceramic Insulated Wire

High temperature resistant ceramic insulated wire is a kind of wire which is made of ceramicglaze as insulated layer. Compared with the traditional insulated wire,ceraminc insulated wirehas advantage of high temperature resistant and high breakdown voltage, it can apply in hightemperature and damp for harsh environment. Die method and Sol-gel are mainly method topreparation high temperature resistant ceramic insulated wire. With sol-gel method porcelaincoating adverse factors such as high cost and long preparation period, whereas Die methodhas advantage of simple equipment, lower cost and short preparation period, in this paper, weuse the Die method to preparation high temperature resistant ceramic insulated wire.The object of paper is to prepare a kind of higt temperature resistant of ceramic insulatedwire,which has high break-down voltage and moderate flexibility(<20D). In this paper, wemake use of high temperature resistance of ceramic glaze, preparation of ceramic glaze asinsulated wire insulation layer, the expansion coefficient of ceramic glaze, glaze slurrystability, as well as the preparation of process parameters were studied.In this paper we discussed the expansion coefficient of different system of glass and thebeginning of melting temperature, the coefficient and melting temperature are considered asmain factors and we used boron lead system as insulating layer which close to the expansioncoefficient of metal nickel. By studying the alkali metal elements of boron lead frittedexpansion coefficient, and points out that with the increase of alkali content in glass graduallyreduce the expansion coefficient, when the alkali metal content is around30%began toincrease, because in this point the alkali metal content in30percent or every increase ofoxygen make two boron atoms by BO3configuration to BO4configuration process is stopped.Beyond the point might form a single bond under considerable concentration of oxygen,reduce network cohesion increase the coefficient of expansion. Studied the relationship ofparticle size with the ball mill time, it is concluded that with rapid grinding ball mill90minX50=0.69μm; X90=1.03μm.We studied the influence of different dispersants on the stability of the suspensionperformance, points out that suspension stability of methyl cellulose as dispersant for spacesteric effect, the mechanism of excessive methyl cellulose is unfavorable for dispersing effect. And polyacrylic acid ammonium as dispersant has electrostatic and steric effect, stablesuspension of polyacrylic acid ammonium, experiments of ammonium polyacrylate dispersingagent determined its dosage is1.5ml/100ml.Studied the effects of process parameters on the porcelain braid glaze layer thicknessbetween10and40microns porcelain coating with suitable mechanical properties andelectrical performance, and viscosity of250mpa s suspension suitable tensile membranespeed of1.0-1.8m/s; Viscosity suitable for300mpa s suspension at the rate of1.2to2.0m/stension membrane; Viscosity suitable for350mpa s suspension of tensile membrane speed is1.5m/s to2.0m/s; Viscosity of400mpa s suspension suitable tensile membrane speed is2.0m/s to3m/s; Drying temperature was60℃. From porcelain coated wire insulation layerthickness in about20microns when both can satisfy the requirement of the breakdownvoltage and can meet the requirements of insulating layer elastic.Establish a mathematical model to study the porcelain coating concentration diffusion ofoxygen in the process of sintering concluded that when the thickness of the insulation layer of20microns porcelain sintering time can’t more than25min, otherwise the oxygen diffusioninternal will lead to the oxidation of the metal which affect the electrical performance.Through to the metal surface of phosphating treatment, can effectively improve themechanical properties of glass coating, by studying the phosphating process, phosphating filmto improve the cohesive strength between metal and enamel coating, and the basis of theobtained phosphating formula is: Ma Ri, salt for3g/100ml, zinc nitrate is8g/100ml, sodiumfluoride is0.45g/100ml; Phosphating temperature of60℃; Phosphating time of15min.