| Electroless nickel-phosphorus alloy with excellent plating ability,high hardness,strong corrosion resistance and wear resistance characteristics,widely used in war industry,automobile,aerospace,decoration and so on.However,the stability of electroless nickel plating bath under the influence of many factors,such as complexing agent,stabilizer,tank material etc.This thesis mainly by optimizing the chemical nickel plating technology process,in view of the different material tank preprocessing and complete chemical nickel plating cycle experiment,to explore its effect law on the stability of electroless nickel plating solution,provide guidance for industrial production.The bath pH,bath stability,cNi2+,cH2PO2-,plating speed,the coating glittering,the phosphorus content of the coating,corrosion resistance of the coating,electrochemical workstation,SEM,XDR as index,the bath stability,morphology and performance of the coating and ingredient has been examined,and explain its mechanism of passivation.The experimental results showed that:1.On the basis of the established technology route and formula,when choosing sulfur-containing stabilizer has yellow material generated in bath surface,using IR measured this material for sulfur compounds;applicable to the system annexing agent was KIO3,organic C,organic matter B,organic matter A,when annexing KIO3 50 mg/L or organic matter A 10mg/L,the solution stability constant was 98%,the phosphorus content of the coating was 12.22%;when annexing organic matter B 4mg/L,the speed was 17.75?m/h;the RE ions with a little were both improve the stability of the plating solution,one of Y3+ was better,upgrade to 11.1h,when the RE ions between 2mg/L and 4mg/L,will increasing plating speed and the coating glittering,but adding rare earth element cerium on citric acid system has obvious selectivity,RE ions used in electroless deposit could make nickel grain smaller and performance of the coating,but have not RE elements of the coating.2.The organic matter A,organic matter B,organic C,and Ce?SO4?2·4H2O complex on Properties of Electroless Ni-P alloy is studied.The experimental results shows that the best combinations is 1.0mg/L organic matter A?10mg/L organic matter B?0.5g/L organic C and 6mg/L Ce?SO4?2·4H2O,the activation energy of the system were 42.7725kJ,the plating speed is 10.92?m/h,the glossiness of coating was 225Gs,the phosphorus content of the coating is 12.96%,the coating structure is uniform and compact,it is significantly layered structure.3.For both 304 and 316 grades of was carried out passivation of stainless steel,the passive film main composition elements is Cr?Fe?Ni and Mo in the form of Cr2O3?FeO?NiO and MoOx.And Y can be improved by adding SiO2 based passivation membrane continuity,compactness,more conducive to establish a complete and continuous stainless steel passivation membrane.4.The same kind of chemical nickel plating bath tub of different material made of chemical nickel plating,the material has an impact on the service life of bath,and little influence on the quality,the service life of beaker tank filled by bath is 12.5 MTO,the service life of PE tank filled by bath is 10.0 MTO,the service life of 304 stainless steel tank filled by bath is 6.0 MTO,the service life of 316 stainless steel tank filled by bath is 9.0 MTO. |
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