Study On Fabrication Of Functionally Graded Materials Based On Components Distinct Different Magnetic Properties

Ceramic-Metal Functionally Graded Materials (FGMs) have the effect to decrease or eliminate stress, due to ceramic-metal dismatching interfaces. It is gradual continuum components and microstructures that content with the extremity conditions in high temperature , high press and other relative environment. There have dual properties as ceramics and metal, resistance of corrosion, high strength, well toughness, and so on. The dismatches in heatexpanded between ceramic and metal can be well solved.A new method which based on distinct different magnetic properties has been exhibited to fabricate the ferro-paramagnet FGMs. Slip-casting was used to mould with suspension slurry containing magnetic particles, and a graded magnetic field was applied during the moulding. The samples were attained after green bodys dried and sintered. Microstructure were characterized, and the function of Ni distribution was deduced which analysis the magnetic particles' motion, evocabled the magnetic force, in the slurry during the moulding.The motion behavior of magnetic particles in ZrO₂/Ni, ZrO₂/Co slurry was researched in sedimentation and viscosity experimentation. PVP can affect the stability of ZrO₂ and ZrO₂/Ni slurry as a dispersant in sedimentation experiment, and the better effect show ZrO₂ slurry with quantity of 0.5wt% dispersant and ZrO₂/Ni slurry with 1.0wt%. The viscosity of suspended slurry have the minimum ZrO₂/Ni with 2.5wt% PVP and ZrO₂/Co with 1.0wt% PVP, and that of slurry increase with the growth of magnetic field intensity. Contrary, it decrease with the growth of rotor velocity. The viscosity of high magnetic components concentration shows lower than that of low magnetic componets concentration, when the intensity of magnetic field exceeds 400mT and the former shows higher than the latter.ZrO₂/Ni FGMs initial 20vol% Ni concentration in slurry was fabricated via slip-casting during the graded magnetic field produced by designed gradient magnetic field. The samples were made up of t-ZrO₂ and Ni, and Ni concentration was continuum distribution from one edge to another with the characterization of optical-microscope and EDX. The theory of Ni distribution function was established base on magentic separation principle and compared with experimental data. The theory can offer the quantitative analysis for FGMs design whichbase on magnetic separation principle.