超高温氧化物共晶陶瓷高梯度定向凝固组织与性能调控研究进展

Research progress on microstructure and property regulation of ultra-high temperature oxide eutectic ceramics by high gradient directional solidification technology

随着航空航天等高新技术领域的迅猛发展,新一代高性能、高效率的超高温结构材料及其制备技术日益成为世界各国航空航天战略发展的重点。超高温氧化铝基共晶陶瓷具有天然杰出的抗氧化、抗腐蚀、抗蠕变、高强度等优良特性,在1400℃以上高温、水氧腐蚀等极端环境下服役具有突出的优势和巨大的发展前景。概述了超高温氧化物共晶陶瓷高梯度定向凝固技术的发展现状;探讨了氧化铝基超高温陶瓷高梯度定向凝固过程中缺陷的形成机理及其抑制措施;重点总结和评述了定向凝固氧化铝基共晶陶瓷的组织特征及均细化调控方法、共晶陶瓷晶体取向及织构调控方法,以及氧化物共晶陶瓷力学性能和强韧化调控方法;展望了高梯度定向凝固技术制备高性能大尺寸氧化物共晶陶瓷的发展趋势和突破点。

With the rapid development of aerospace and other high-tech fields,a new generation of high perfor-mance,high efficiency ultrahigh temperature structural materials and their preparation technologies increasingly becomes the focus of the development of aerospace strategy in the world.Ultrahigh temperature alumina based eutectic ceramics have excellent intrinsic oxidation resistance,corrosion resistance,creep resistance,high strength and other excellent properties.Therefore,they have outstanding advantages and great development prospect in extreme environment such as ultrahigh temperature above 1400℃,water and oxygen corrosion circumstances.In this paper,the current development status has been firstly introduced for the ultrahigh temperature oxide eutectic ceramics prepared by high gradient directional solidification technologies.Then,the formation mechanism and control method of the defects during the high gradient directional solidification process of the alumina based ultrahigh temperature eutectic ceramics have been summarized.Furthermore,the microstructure characteristics and homogenization control methods,crystal orientation and texture control methods,mechanical properties and strengthening-toughening control methods of oxide eutectic ceramics have been reviewed.Finally,the development trend and breakthrough point have been comprehensively prospected for the preparation of oxide eutectic ceramics with high performance and large size by high gradient directional solidification technologies.