ZTA蜂窝陶瓷增强铁基复合材料界面过渡层的形成机制及其对磨料磨损性能的影响

In order to solve the infiltration difficulty of iron melt into ceramic preforms of ZTA (ZrO2 toughening Al2O3) particles, and to improve the ZTA/iron interface bonding strength for the ZTA particles reinforced iron matrix honeycomb-shaped composites, an interaction infiltration technology was invented in the early study of this project in which fine active ceramics powders such as B4C and TiO2 were first coated on ZTA particles in the preforms, then interacted with ZTA and the iron melt during infiltrating, so that the iron melt infiltrated into the preforms much more easily than before, and a interfacial layer thick more than 10 micrometer generated at the ZTA/iron interface. .The project focuses on a study on basic theories such as the formation mechanism of the interfacial layer, its effect on the interfacial continuity and interfacial bonding strength at ZTA/iron interface, the correlation between the interfacial bonding strength and the abrasive wear resistance of the composites. For these purposes, both advanced material test methods, characterization techniques and multi-scaled computer calculation, simulation method will be applied in the project, and cooperate to interpret at the atom and electron scale the scientific reasons of the formation, the properties of the interfacial layer, its influence on the interfacial bonding strength, to explore the influence factors and control methods to the interaction infiltration process at mesoscale and macroscale, and a model will be set up for the interaction infiltration process. The influence rule of the factors such as the phases and the thickness for the interfacial layer, the structure parameters of the honeycomb-shaped preforms and the interfacial bonding strength, to the abrasive wear resistance will be studied so as to improve the bonding strength at ZTA/iron interface and the abrasive wear resistance..The project will provide a new method to realize the infiltration and improve interfacial bonding for the non-wettable composite system, develop the composite infiltration theory and support the application of the wear resistant metal matrix composites in the industry in theory.

为解决氧化锆增韧氧化铝（ZTA）陶瓷颗粒增强铁基复合材料铸渗复合困难、界面结合强度低的问题，本项目在蜂窝状陶瓷预制体的ZTA颗粒表面包裹B4C、TiO2等活性陶瓷微粉，通过反应浸渗的方法改善铁液对ZTA预制体的浸渗能力，同时在ZTA颗粒和铁基体间生成界面过渡层，提高界面结合强度。项目将先进的实验表征技术和材料多尺度的计算与模拟方法相结合，从原子电子层次上深入阐释界面过渡层的形成、性能及界面结合强度的科学本质，并从介观和宏观尺度上探究反应浸渗过程的影响因素与控制途径，建立反应浸渗过程的理论模型；研究界面过渡层物相、厚度及蜂窝陶瓷预制体结构参数对复合材料界面结合强度及抗磨料磨损性能的影响规律，从而优化复合材料界面，提高其耐磨性。项目为解决非浸润型的陶瓷/金属基复合材料铸渗和改善其界面结合提供新思路与新方法，将丰富复合材料浸渗理论，为陶瓷增强钢铁基耐磨复合材料的工业应用奠定理论基础。

为解决氧化锆增韧氧化铝(ZTA)陶瓷颗粒增强铁基复合材料铸渗复合困难、界面结合强度低的问题, 本项目在氧化锆增韧氧化铝（ZTA）颗粒表面包覆B4C、TiO2、SiC及Al2O3等不同种类的活性微粉，制备出具有蜂窝构型的陶瓷预制体，并通过反应铸渗的方法获得了ZTA颗粒增强铁基复合材料。利用铁液在预制体中的渗透作用，促进了微粉与陶瓷颗粒和金属发生双向反应，在形成反应型过渡界面的同时提高铁液的浸渗能力。采用EPMA、微区XRD、TEM和纳米压痕等手段表征了反应型过渡界面的组织及性能，结果表明过渡界面处的物相以非晶相为主，其硬度和模量等性能介于陶瓷和金属之间，可起到良好的过渡作用。通过第一性原理计算不同包覆粉体与基体的粘附功和界面能差，发现复合材料的界面结合强度得到显著提升。将制备工艺参数与反应浸渗过程相关联，获得最佳的浇注速度为0.2m/s。阐明了ZTA颗粒增强铁基蜂窝构型复合材料的磨损机制，优化出最佳的孔径/孔壁比等结构参数，显著提高了材料的耐磨性。本项目的开展为陶瓷/金属基复合材料的铸渗和界面结合的改善提供了新思路与新方法，丰富了复合材料浸渗理论，为陶瓷增强钢铁基耐磨复合材料的工业应用奠定了理论基础。