反应合成ZrAl3金属间化合物及其形核行为

采用自蔓延高温合成反应,应用Zr和Al粉末制备了ZrAl3金属间化合物,并利用XRD、DTA 和 SEM 等分析手段,研究了SHS合成ZrAl3相的反应行为.结果表明,自蔓延合成ZrAl3的反应起始于Al与Zr的固-固反应,然后扩展列液-固反应,最后完成于后烧阶段.ZrAl3颗粒呈现不规则的石块状,且其表面布满许多树枝状的凹纹.在Zr-AI体系中,当Zr/Al is≤1(原子比)时,ZrAl3是唯一形成的相,其形成与所设计初始粉末的成分无关,并详细讨论了ZrAl3相的形核形为.

Reaction Synthesis of ZrAl3 Intermetallic Compound and Its Nucleation Behavior

Using self-propagating high-temperature synthesis(SHS)reaction,ZrAl3 intermetallic compound was fabricated from Zr and Al elemental powders and its reaction behavior was investigated by XRD,DTA and SEM analysis.The result reveals that the synthesis process of ZrAl3 initiates from solid-solid reaction,then further extends to solid-liquid reaction,and finally was completed at afterbuming stage.The ZrAl3 grain takes on irregular block-like morphology and many sunken dendrites appear on its surface.In Zr-Al system,when the ratio of Zr/AlS≤1,the formation of ZrAl3 iS independent on the expected composition of starting mixtures.Finally,the nucleation behavior of ZrAl3 was discussed in detail.