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对采用布里奇曼定向凝固技术制备的Ni-Si共晶复合材料的晶体生长机理进行了研究。结果表明,在初始过渡区形成的是较粗大的金属间化合物和α-Ni基体。在稳态晶体生长区,形成了α-Ni、Ni_3Si、Ni_31Si_(12)三相。在分析已有的热力学数据基础上,采用双参数模型,并通过模型求解,估算了二元金属化合物Ni_3Si、Ni_31Si_(12)的标准生成焓,并从热力学角度,探索了亚稳相的形成机理。
The crystal growth mechanism of Ni-Si eutectic composite prepared by Bridgman directional solidification technique was studied. The results show that in the initial transition zone is formed coarser intermetallic compounds and α-Ni matrix. In steady-state crystal growth zone, three phases of α-Ni, Ni_3Si and Ni_31Si_ (12) were formed. Based on the analysis of existing thermodynamic data, the standard enthalpy of formation of binary compounds Ni_3Si and Ni_31Si_ (12) was estimated by using a two-parameter model and solved by the model. The formation mechanism of metastable phases was also discussed from the thermodynamic point of view .