Research Of Mo-20Cu Alloy Prepared By Chemical Plating

Mo-Cu alloy Material is made up of non-magnetic Material Cu and Mo formedby the proportion according to the demand of miscibility of pseudo alloy,bipolarComposite materials(Composite Material).The material performance is stable and hashigh ablation resistant characteristics,low porosity, excellent mechanical properties.Itcan be adjusted according to the need for material composition flexibly, so Mo-Cualloy has broad prospects for development with its unique performance.This experiment adopts the method of electroless Cu plating of compositepowders.High density Mo-Cu alloy is prepared by solid-liquid two-phase sinteringmethods.we carry on the deep discussion on the plating process and sinteringprocess,then research the influence of process parameters on the alloy comprehensiveperformance comprehensively.Getting the conclusions,as follows:（1）Preprocessing (coarsening of Mo powder, sensitization and activation),before plating pretreatment can change Mo powder micro morphology structure andto enhance the surface activity, improve the Mo powder surface and the adhesionstrength of the Cu particles and facilitate the implementation of the plating process.（2）The configuration of the Cu plating solution.Copper ion content of24g/L,Reducing agent hydrazine hydrate0.35mol/L,Crossing the liquid PH of11.5～12,Content of polyvinyl pyrrolidone12ml/L,Citric acid content of10ml/L,Constanttemperature water bath is set to65～75℃.When crossing the liquid adding organicadditive ingredients can form a variety of organic polymer particles which can controlthe direction of Mo-Cu nucleation and location and space.（3）Cleaning and drying process of compound powder.Mo-Cu compositepowders need to be cleaned and remove surface impurities;Taking hydrogen drying isin order to protect the metal Cu.Setting the drying temperature is240℃, time is120minutes.（4）Preforming and final forming are two ways for forming compositepowders.Preforming uses100t four-column type hydraulic oil equipment prefabricateinto embryo;Eventually forming adopts cold isostatic pressing equipment for stress evenly dispersed, setting the pressure350MPa.（5）Alloy sintering process parameters.The best sintering temperature is1150℃for insulation sintered by stages to make the temperature uniform fully;Hightemperature sintering holds time120minutes;Hydrogen as a protective gas, hydrogenflux rate is10~15ml/L.Sintering process has a significant impact on the alloydensity;Using scientific and reasonable sintering process can reduce the presence ofporosity,make the alloy composition uniform distribution and obtain goodcomprehensive properties of alloy.Evaluating the performance of the alloy,themeasured density reached more than99.25%, closing to full density;Microstructureobserved its compact structure, no visible flaws,Mo and Cu facies show each otherspiral wound mesh distribution;EDAX shows that the alloy composition is uniform,the micro area composition no difference.Using eddy current conductivity meter totest its conductivity is45.83%(IACS), conductive good performance.The hardness ofalloy is181.1kg f/mm2.（6）By analysis of alloy solid-liquid sintering densification mechanism getsthat density and the relate density of the overall trend is rising with the increase oftemperature, density and the relate density of1150℃after falling.Organizationcomposition homogeneous alloy,its internal micro zone groups micro hardness valuewon’t have too big difference and the internal porosity is less.Mo is coated perfectlyby Cu particle.Liquid Cu can short-circuit diffusion on the surface of Mopowder,reducing surface free energy provides driving force needed for thediffusion.The increase of sintering temperature, the space of germ will collide witheach other.The body parts form open clusters and interaction which cause the mutualdiffusion of Mo and Cu powder,having a positive role on densification of alloy.