稀土-WSi_2/MoSi_2复合材料的合成与性能

Synthesis of MoSi_2 matrix composite reforced by rare earth and WSi_2 and its mechanical properties

通过X射线衍射,分析讨论了机械合金化和高温自蔓延方法合成稀土-WSi2/MoSi2复合材料粉末过程中的相变化;比较了MoSi2、WSi2/MoSi2和稀土-WSi2/MoSi2等3种材料的性能.结果表明:高温自蔓延合成方法比机械合金化合成方法更合适于合成稀土-WSi2/MoSi2复合材料粉末;采用SHS合成+球磨的工艺可获得高致密的复合材料.机械合金化合成稀土-WSi2/MoSi2复合材料粉末过程中,Mo、W、Si相遵循Mo(W)固溶体、Si固溶于Mo(W)、WSi2/MoSi2相的形成规律;且随着稀土含量的增加,合金化过程延迟.复合添加稀土和WSi2比单一添WSi2对基体MoSi2具有更好有综合强韧化作用.图4,表1,参16.

The phase transformation had been analyzed by X-ray during synthesis of rare earth - WSi_2/MoSi_2composite by mechanical alloying and self-propagating high-temperature synthesis.And the mechanical properties of MoSi_2、WSi_2/MoSi_2 and rare earth-WSi_2/MoSi_2 was compared each other. Results show that rare earth-WSi_2/MoSi_2 powders are easier to be synthesized by self-propagating high-temperature synthesis than by mechanical alloying.It is right to prepare enough compact composite by using the technique of self-propagating high-temperature synthesis followed by milling.During the mechanical alloying process,Mo(W)solid solution,Si solving in Mo(W) and WSi_2/MoSi_2 formation is ordinal discovered. With the increases of content of rare earth,the alloying process is delayed.Effect of strengthening and toughening on MoSi_2 matrix reforced by rare earth and WSi_2 is more obvious than only reforced by WSi_2.4figs.,1tab.,16refs.