Ti(C,N)/AlCoCrFeNi金属陶瓷的高温抗氧化机理

High Temperature Anti-oxidation Mechanism of Ti(C,N)/AlCoCrFeNi Cermets

本文从热力学角度和氧化膜完整性两方面深入研究了Ti(C,N)/AlCoCrFeNi金属陶瓷的高温抗氧化机理。结果表明,多主元AlCoCrFeNi高熵合金的引入对Ti(C,N)基金属陶瓷抗氧化性能的显著提升主要归因于氧化过程中粘结相组元Al、Cr活性较强,倾向于被优先氧化,其形成的AlTiO5和Cr_4WO_6复合氧化膜不仅自身组织致密度高,对基体有完整的覆盖性,且能有效减小氧化膜的生长应力,遏制氧化膜的破裂剥落,使得氧化膜与合金基体结合紧密,从而氧的传输被极大地抑制,有效减缓了氧化进程。

In this paper,high temperature anti-oxidation mechanism of Ti（C,N）/AlCoCrFeNi cermets was studied by the thermodynamic analysis and oxide scales integrity examination.The result shown that the addition of multi-component AlCoCrFeNi high entropy alloy to Ti（C,N）-based cermets showed an optimum high temperature oxidation resistance behavior.The outstanding oxidation resistance was mainly ascribed to the high activity of elemental aluminum and chromium concentrations in the binder phase.These active components tend to preferentially oxidized and urge the formation of composite oxide film consisting of AlTiO5 and Cr4WO6 compound.The formed oxide film is not only dense and continuously covered on the surface of matrix,but also reduce the growth stress and curb its spalling failure process.Therefore,it makes the oxide film closely deposited on the alloy substrate,which impedes the inward oxygen transport from the environment to the oxide-alloy interface,and the oxidation process is slowed down effectively.