冷冻铸造技术制备仿贝壳层状结构陶瓷复合材料研究进展

贝壳珍珠层是一种天然的层状结构复合材料,类似"砖和泥"的软硬相交替的层状分级组装结构赋予其优良的力学性能。通过对贝壳的珍珠层进行仿生研究,人们已利用不同技术如冷冻铸造技术等,制备了一系列仿生高强超韧层状复合材料,并且这些材料在航空航天、军事、民用及机械工程等领域表现出广阔的应用前景。首先介绍了贝壳珍珠层的结构性能,并对其断裂机制进行了阐述;然后综合介绍了冷冻铸造技术的发展历程、作用机理、控制因素、装置设计和总体工艺流程。在此基础上,对制备仿贝壳层状结构陶瓷复合材料的表观密度、多孔陶瓷的孔隙率进行介绍,综述了多孔陶瓷的性能、陶瓷/金属层状结构复合材料以及陶瓷/聚合物层状结构复合材料的特点和应用,最后分析和总结了在研究仿贝壳层状结构陶瓷复合材料过程中出现的问题,并对该复合材料的未来发展趋势做了一定的预测。

Applying Freeze-casting Technique to the Fabrication of Nacre-like Lamellar Structured Ceramic Composites:A State-of-the-art Review

Shell nacre is a natural layered composite and has a layered hierarchical assembly structure similar to the "brick and mortar" structure with the alternation of hard and soft phase,which endows it with excellent mechanical properties.Through the bionic study of shell nacre,people have used different technologies(such as freeze-casting technology) to prepare a series of bionic and layered composite materials with high strength and toughness,which show broad application prospects in aerospace,military,civil use,mechanical engineering and other fields.The performance and facture mechanism of shell nacre structure are reviewed firstly.Then the development process,mechanism,control parameters,device design and overall processing steps of freeze-casting technology are introduced.On this basis,the stability,apparent density and porosity of porous ceramics,used for preparing bionic and la-yered composite materials,is introduced.Meanwhile,the characteristics and applications of porous ceramics,ceramic/metal layered composites and ceramic/polymer layered composites are reviewed.Lastly,the analysis and summary of problems appeared in the preparation of ceramic with nacre-like lamellar structure was made,and the future development and research trend of this composite is predicted.