Open-cell silicon carbide(SiC)foams with high performance were prepared from aqueous slurry by the organic foam impregnation and infiltration reaction sintering process with polyurethane sponges as the sub-strates.SiC ceramic struts formed a three-dimensional network connected structure similar to foam.The cells in the foams are randomly oriented,and mostly homogeneous in size and shape.Average pore size is about 2 mm. Controllable relative densities varied fromabout 15vol% to about 42vol%,which leaded to compressive strengths of SiC foams ranged betweenabout 11 MPa to about 50 MPa and flexural strengths varied from about 7 MPa to about 25 MPa.Deformation behavior of the SiC foams was investigated.When SiC foams were de-formed,the stress-strain curve showed approximately only one linear-elastic region and this was different from those of ceramic foams reported.This is possible because of the struts with fine microstructure had high density and high strength.Therefore,the SiC foams are uniform and the struts could response homogeneously to load transmitted through the foams.The thermal conductivity measurement indicated that the materials had excel-lent thermal conductivity properties and the materials could be processed into a complex shape that could be a-dapted to a variety of application requirements.%采用有机泡沫浸渍结合熔渗反应烧结技术制备了一种高性能泡沫 SiC,该种泡沫陶瓷由 SiC 陶瓷孔筋形成类似于泡沫的三维网络连通结构,平均孔径尺寸约2 mm,相对密度15%~42%(体积分数),具有高的可控性,其强度随密度增加而提高,压缩强度11~48 MPa,弯曲强度7~25 MPa.研究了材料受力时的变形行为,结果表明,该种泡沫SiC具有不同于常见报道中的泡沫陶瓷的形变机制,其应力应变曲线只有弹性变形阶段,原因在于材料整体均匀性高,陶瓷孔筋组织致密且晶粒细小,受力时表现出良好的整体协调性.材料具有优良的热导性能.同时该种材料还可以加工成复杂形状,可适应各种应用需求.
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