激光干涉空间选择性形成金属间化合物Ni3Al

Spatially selected intermetallic reaction of Ni_3Al by laser interference structuring

金属间化合物,例如Ni-Al、Ti-Al系合金,是指不同种类的原子长程有序排列构成的有较确定化学当量比的合金相.这类合金相原子间结合力强,具有高温结构材料所期望的优异性能.然而这类合金普遍存在室温塑性差、高温抗蠕变性差以及环境脆性敏感等问题.本文利用激光干涉图样对应的温度分布,空间选择性地产生Ni和Al的金属间化合物Ni3Al,以线阵或点阵的方式局域金属间化合反应形成了软、硬属性交替的薄膜材料,为改善塑性及脆性敏感等问题探索新的解决途径.对所制备样品进行的白光干涉显微镜(WLI)和原子力显微镜(AFM)分析给出了样品的表面形貌特征;X射线衍射(XRD)和纳米硬度测试给出了金属间化合物合金相及其微观硬度分布.

Intermetallic compounds, such as Ni - Al, Ti - Al alloy, are referred to the alloy of a definite composition with different atoms of specific stoichiometric ratio, and arranged orderly in long distance. This alloy has a strong binding force among atoms, and can resist high temperature. But the common drawbacks of this kind of ally are the lack of plasticity, the inferior capacity of anti - creeping, and the environmental sensitive brittleness. In this work, the intermetallic reaction of Ni and Al was promoted in a spatially resolved manner, taking advantage of the temperature distribution induced by the later interference pattern. Thus intermetallic Ni3 Al was developed in the forms of dot - array or line - array, so as to get a thin films with alternative hard and soft properties on its surface. This can be a new way to solve the problem of plasticity and brittleness for the intermetallic compounds.