Development of B6O-based materials for wear applications

B6O材料是开发新型超硬耐磨材料的重要候选材料。在以前的工作中，申请人已经发现，烧结添加剂提供了通过FAST/SPS(放电等离子烧结)或HIP(热等静压)对B6O进行可重复的液相辅助致密化的可能性。对于可重复致密化和由此产生的材料性能的定制，了解在致密化过程中发生的过程并开发这些材料的微结构-性能关系是至关重要的。在拟议的项目中，将制备不同添加剂组成的B6O材料，并在不同的烧结条件下对其微观结构和所产生的力学性能进行表征。本研究的主要范围是所形成的微观结构(即B6O颗粒中的平面缺陷，被认为是导致B6O材料中异常晶粒生长的原因)与测量的力学性能，特别是硬度和断裂韧性，这是已知的控制材料耐磨性的主要性能。预计对目前尚未解决的关于增韧机制的问题以及观察到的多晶B6O材料与单晶数据相比硬度下降的问题的基本了解将导致工具允许定制微结构，从而使B6O材料具有可调节的性能。

B6O materials are a promising candidate for the development of new superhard and wear-resistant materials. In prior works the applicants have discovered that sintering additives offer the possibility for a reproducible liquid phase-assisted densification of B6O by FAST/SPS (Spark Plasma Sintering) or HIP (hot-isostatic pressing). For the reproducible densification and the tailoring of the resulting material properties, it is essential to understand the processes taking place during densification and to develop microstructure-properties relationships for these materials. In the proposed project, B6O materials with different additive compositions and under the use of different sintering conditions will be prepared and characterized in respect to their microstructure and the resulting mechanical properties.The main scope of this study is a correlation of the developed microstructure (i.e. planar defects in B6O grains which are supposed to be responsible for the occurrence of abnormal grain growth in B6O materials) with the measured mechanical properties, in particular the hardness and the fracture toughness which are known to be major properties for controlling the wear resistance of materials. It is expected that a fundamental understanding of the currently unsolved questions regarding the occurring toughening mechanisms and the observed decrease of the hardness of polycrystalline B6O materials in comparison to single crystal data will result in tools which allow a tailoring of the microstructure and thus B6O materials with adjustable properties.