Fabircation And Characteirzation Of Al₃BC₃Ceramic Mateirals

In this work, using spark plasma hot sintering research the technology of s-ynthesis Al₃BC₃ceramic（spark plasma sintering is new tepy technology of fabr-ication materials, that can reduce sintering teperature and holding time.）, and u-sing pressureless sintering fabricate porous materials. The influences of the diff-erence ratio of starting materials on Al₃BC₃-based ceramics are prepared by pre-ssureless sintering; the influences of using spark plasma sintering study speciesof mould designing on Al₃BC₃ceramics are prepared by spark plasma sintering;the influences of studying spark plasma sintering on the preparation of Al₃BC₃ceramics is fabricated by spark plasma sintering.The influences of the difference ratio of starting materials on Al₃BC₃-basedporous ceramics are prepared by pressureless sintering: Al₃BC₃-based porous cer-amics are prepared by pressureless sintering using Al, B4C, and graphite powde-rs as the starting materials. The influences of molar ratio of starting materials o-n the purity, open porosity, and pore size of the Al₃BC₃-based porous ceramicsare investigated. Graphite is the main impurity of the Al₃BC₃-based porous ce-ramics and can be eliminated by adjusting the molar ratio of starting material.With the molar ratio of Al:B4C:C=3.2:0.25:2.30, high pure Al₃BC₃porous cera-mic is successfully fabricated by pressureless sintering in vacuum at1800oC for2h. The open porosity of the Al₃BC₃-based porous ceramics ranges from36%to47%. The pores are uniformly distributed.the influences of using spark plasma sintering study species of mould desi-gning on Al₃BC₃ceramics are prepared by spark plasma sintering:we design do-uble mould, one is single pressing sintering, further more another is two-directi-on pressing sintering; single pressing is apattern of gradient sintering, the prim-ary difference of mould fluctuate surface of area result in the different currentdensity through mould fluctuate surface, accordingly that cause gradient; In thesintering process, we find that the shortcomings of single sintering form temper-ature gradient in sintering materials of single crystal and polycrystalline material-ls, which lead to nonuniform sintering; two-direction pressing sint-ering is a p-attern of uniformity sintering, mould fluctuate surface ofarea is consistence, wh-ich cause uniformity current density by moulding, the fluctuate sample is consi- stent for sintering conducting materials and non-conducting materials; In the sit-ering process we find that the advantage of two-direction pressing form both d-ensity and uniformity sample in the single crystal materials, composite materialsand polycrystalline materials. the influences of researching spark plasma sintering on the preparation of Al₃BC₃ceramics is fabricated by spark plasma sintering:the different ratio of raw material and the different temperature fabricate Al3BC3ceramics,（1）in the same temperature andthe different proportions of raw mate-rial powder, the analysis of XRD patterns indacate that pure Al₃BC₃can be fa-bricated with a molar ratio of3:1:3. The main impurity is graphite;（2）with amolar ratio of3:1:3, the synthsis of high density Al₃BC₃material reduce impur-ity phase with the increasingly of teperature, Al₃BC₃material attain98%under1650oC;（3）Grain show long plate-like, grain of the average length is85.5μm, t-he average width is17.5μm, length-width ratio was4.8; slender plate-likesimilarto other layered ternary carbon boron aluminum such as Ti3SiC2and Ti3AlC2.