摘要
Ti_(2)AlC MAX相涂层是一类兼具金属和陶瓷特性的具有密排六方结构的高性能陶瓷涂层,在电接触、高温防护、宽温域摩擦等领域具有广阔的应用前景。然而MAX相涂层的成相成分窗口窄,性能受杂质相影响大,实现高纯、致密Ti_(2)AlC MAX相涂层的制备目前仍存在挑战。考虑沉积气压与溅射等离子体能量密切相关,采用高功率脉冲复合直流磁控溅射技术在钛合金基体上制备了TiAl/Ti-Al-C涂层,经后续热处理退火得到高纯Ti_(2)AlC MAX相涂层,重点研究不同沉积气压对涂层退火前后的成分、微观结构以及力学性能的影响和作用机制。结果表明,随着气压不断增大,沉积态涂层厚度先增加后减少。其中低沉积气压下沉积态涂层退火后,结构中除了Ti_(2)AlC MAX相外,还含有一定量杂质相;而在高气压下沉积态涂层退火后几乎全部转变为Ti_(2)AlC MAX相,呈现高纯、表面光滑致密的MAX相涂层特征。相较于沉积态涂层,退火后的涂层硬度变化不大,但由于生成了Ti_(2)AlC MAX相,涂层弹性模量有所提高。
Ti_(2)AlC MAX phase coating is a kind of high-performance ceramic coating with dense hexagonal structure,which benefits the combined superior properties from metals and ceramics and the promising applications in electric contact,high temperature protection etc.However,due to the narrow formation and the high deposition temperature of MAX phase,it is still an open challenge to realize the Ti_(2)AlC MAX phase coating with high purity and dense structure.Therefore,the TiAl/Ti-Al-C coating is firstly deposited on titanium alloy substrate by a home-made high-power pulsed magnetron sputtering technology,where the subsequent heat treatment is performed to fabricate the high-purity Ti_(2)AlC MAX phase coating.In particularly,the composition,structure and mechanical properties of the Ti_(2)AlC MAX phase coating is investigated as a function of working pressure during deposition.The results show that increasing the pressure lead to the first increase and then the decrease of deposited coating thickness.After annealing,the coating obtained under low deposition pressure except Ti_(2)AlC MAX phase,the structure also contains a certain amount of impurity phase.However,the coating prepared under high deposition pressure presents the high purity Ti_(2)AlC MAX phase and the compact smooth surface after annealing.Note that the hardness of coating is slightly deteriorated after annealing,while the elastic modulus is improved due to the laminar structural formation of Ti_(2)AlC MAX phase coatings.
作者
周定伟
李忠昌
王振玉
马冠水
柯培玲
胡晓君
汪爱英
ZHOU Dingwei;LI Zhongchang;WANG Zhenyu;MA Guanshui;KE Peiling;HU Xiaojun;WANG Aiying(College of Materials Science and Engineering,Zhejiang University of Technology,Hangzhou 310000,China;Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences,Ningbo 315201,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2022年第5期236-245,共10页
China Surface Engineering
基金
国家自然科学基金(52025014,52171090,51901238)
宁波市自然科学基金(202003N4025)资助项目
