原位反应法制备Fe-Cr-Ni/TiC(p)复合材料的组织结构与抗氧化性

STRUCTURE AND OXIDATION RESISTANCE OF Fe-Cr-Ni/TiC(p) COMPOSITE PREPARED BY IN-SITU SYNTHESIS

利用原位反应法制备了Fe - 2 6Cr- 14Ni+3mass%TiC(p)和Fe - 2 6Cr- 14Ni+6mass%TiC(p)复合材料 .复合材料由平均尺寸为 0 5～ 5 μm的TiC颗粒与γ基体组成 ,TiC中存在α/ 2 [11- 0 ]和α/ 2 [0 1- 1]型高密度位错 ,TiC颗粒与γ相间界面为共格界面 ,二者存在下列位向关系 :(2 - 2 0 ) TiC∥ (0 2 0 ) γ,[0 0 1]TiC‖ [0 0 1]γ.1473K下的抗氧化性实验结果表明 ,TiC颗粒的存在使复合材料的初始氧化阶段具有短路扩散效应 ,两种复合材料的氧化动力学曲线分别符合抛物线和对数增长规律 ,在稳定氧化阶段 ,复合材料比基体合金具有更优良的抗氧化性能 ,氧化膜主要由多面体状Cr2 O3 和FeCr2 O4

Fe-26Cr-14Ni+3 mass%TiC(p) and Fe-26Cr-14Ni+6 mass%TiC(p) composites are prepared by in situ synthesis.The composites are composed of γ matrix and the TiC particulate with an average size of 0.5 μm～5 μm.TiC particulate contains a great deal of α/2-0] and α/2 and α/2-1] type of dislocation.The interface between TiC particulate and γ phase is a coherent interface with the orientation relationship (2 type of dislocation.The interface between TiC particulate and γ phase is a coherent interface with the orientation relationship (2-20) TiC ∥(020) γ, TiC ‖ γ.The oxidation experiment of the composites shows that TiC particulate causes an effect of short circuit diffusion at initial oxidation stage,the oxidation kinetic curves of the composites with 3 mass% TiC and 6% TiC follow the parabolic and logarithmic rule,respectively.The composites are of better oxidation resistance than the matrix alloy at stable oxidation stage.The oxide scale is mainly composed of polyhedron like Cr 2O 3 and FeCr 2O 4.