中文摘要：

氧化物最容易溶解在 situ composites 陶器因为他们的优秀高温度的力量，在高温度的结构的材料的申请吸引了重要兴趣，氧化并且爬抵抗，以及突出的微结构稳定性。在 situ 高级低共熔体的方向性地团结的第三的 Al2O3/YAG/ZrO2 合成被一个激光地区 remelting 方法成功地准备，试图调查生长特征在下面超离频温度坡度。微观结构和阶段作文同样团结高级低共熔体被使用扫描电子显微镜学(SEM ) 描绘，精力散光谱学(版本) ，和 X 光检查衍射(XRD ) 。结果证明合成礼品由好 Al2O3 和钇铝柘榴石阶段组成的典型高级低共熔体的薄片状的微观结构，和有更小的尺寸的充实的 ZrO2 阶段在 Al2O3/YAG 接口并且在 Al2O3 阶段是随机分布式的。激光力量和扫描的率强烈影响样品质量和微观结构特征。另外，粗糙的殖民地微观结构也被观察，并且他们的形成和微观结构上的温度坡度的效果被讨论。

英文摘要：

Oxide eutectic ceramic in situ composites have attracted significant interest in the application of high-temperature structural materials because of their excellent high-temperature strength,oxidation and creep resistance,as well as outstanding microstructural stability.The directionally solidified ternary Al2O3/YAG/ZrO2 hypereutectic in situ composite was successfully prepared by a laser zone remelting method,aiming to investigate the growth characteristic under ultra-high temperature gradient.The microstructures and phase composition of the as-solidified hypereutectic were characterized by using scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,and X-ray diffraction（XRD）.The results show that the composite presents a typical hypereutectic lamellar microstructure consisting of fine Al2O3 and YAG phases,and the enriched ZrO2 phases with smaller sizes are randomly distributed at the Al2O3/YAG interface and in Al2O3 phases.Laser power and scanning rate strongly affect the sample quality and microstructure characteristic.Additionally,coarse colony microstructures were also observed,and their formation and the effect of temperature gradient on the microstructure were discussed.