采用ＳＨＳ工艺，在１００ＭＰａ高压氮气下，制备了致密的ＡＩＮ－ＴｉＣ陶瓷，相对密度达９５％，抗弯强度达２４０ＭＰａ．研究表明，ＡＩ－Ｎ２－ＴｉＣ体系ＳＨＳ过程中，当反应温度升至６６０℃时，ＡＩ熔化．高温下熔融ＡＩ在ＴｉＣ表面发生漫流现象，在ＳＨＳ反应区发生液相烧结，从而使反应区孔隙率显著下降，当开气孔闭合时在气相等静压作用下形成致密产物．随着ＴｉＣ含量增加，液相烧结作用增强，产物致密度显著提高，抗弯强度及断裂韧性提高．ＡＩ－Ｎ２－ＴｉＣ体系的ＳＨＳ致密化主要发生在燃烧波蔓延方向，具有明显的方向性．
Compact AlN-TiC ceramics were fabricated by combustion synthesis of Al particles in
super-high pressure nitrogen (100MPa), and the maximal relative density of 95% can be gained in the products, and maximal bending strength reached
240 MPa. In the SHS process of Al-N2-TiC system, when the temperature was up to 660℃, Al melted. At high temperature of SHS
reaction melting, Al spread over TiC particle surfaces, which led to liquid sinter occur in the SHS reaction zone. With liquid sinter occurred,
the porosity of reaction zone apparently decreased. With increasing of TiC content in the original powder system, liquid sintering strengthened,
and relative density of the products improved, bending strength and fracture toughness increased. In Al-N2-TiC system, SHS-densification
had apparent tropism, mainly occurred along the combustion front.
参考文献
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