为了研究添加Al粉对自蔓延高温合成β-Mo（Si，Al）2的影响，以Si、Mo 和Al粉为原料，按照化学式Mo（Si1-xAlx）2（x分别取0、0．1、0．2、0．3、0．4，即Al取代Si物质的量依次为0、10％、20％、30％、40％）配料，采用自蔓延高温合成制备了不同Al含量的β-Mo（Si，Al）2，并利用X射线衍射仪和扫描电镜对合成产物进行了相组成和产物形貌分析。结果表明：Al的加入有利于自蔓延反应进行得更加完全，在自蔓延过程中，Al进入到MoSi2晶格中，发生 Al、Si 取代，当 Al 取代 Si 物质的量达到40％时，仍能实现 Al 的合金化，生成高温相β-Mo（Si，Al）2，并且随着Al的添加会使自蔓延合成产物的晶格发生严重变形。通过SEM观察发现：加入Al粉的合成产物形貌都呈现出小颗粒的聚集状态，且小颗粒为球形或接近等轴状，颗粒平均粒径为2～5μm，说明自蔓延合成产物的形貌继承了Mo粉的原始形貌，而与Al粉加入量没有明显关系。
β-Mo(Si,Al)2 with different Al additions was prepared by self-propagating high-temperature synthe-sis (SHS)using Si,Mo and Al powders as starting materials,batching according to Mo(Si1-xAlx)2 (x=0, 0.1,0.2,0.3,and 0.4,corresponding to Al substituting 0,10%,20%,30%,and 40%of Si in molar ratio,respec-tively)in order to research effect of adding Al powder on SHS ofβ-Mo(Si,Al)2.The phase composition and morphology of the synthesized compounds were investigated by XRD and SEM.It is found that,the self-prop-agation reactions are prompted by introducing Al;Al enters in MoSi2 lattice to substitute Si during the SHS process;when Al substitution reaches 40%,the alloying of Al can still be realized forming high temperatureβ-MoSi2 phase,and the lattices of synthesized compound deform seriously with the increase of Al addition. SEM analysis shows there are small particle aggregates in the synthesized compounds added with Al,and small particles are spheric or near equiaxed with 2-5 μm of average size,which means the morphology of the SHS products is similar with the original morphology of Mo powders,independent of Al addition.
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