TC4合金仿生结构化激光氮化工艺与抗汽蚀性能研究  

Bionic Structured Laser Nitriding and Anti-cavitation Performance of TC4 Alloy

作　　者：吴国龙 张玉清 秦心卉[1,2,4] 吴浩 王晔 陈智君[1,2,3] 姚建华 WU Guolong;ZHANG Yuqing;QIN Xinhui;WU Hao;WANG Ye;CHEN Zhijun;YAO Jianhua(Institute of Laser Advanced Manufacturing,Zhejiang University of Technology,Hangzhou 310023;Special Equipment Manufacturing and Advanced Processing Technology,Ministry of Education/Zhejiang Provincial Key Laboratory,Hangzhou 310023;School of Mechanical Engineering,Zhejiang University of Technology,Hangzhou 310023;School of Science,Zhejiang University of Technology,Hangzhou 310023)

机构地区：[1]浙江工业大学激光先进制造研究院,杭州310023 [2]特种装备制造与先进加工技术教育部/浙江省重点实验室,杭州310023 [3]浙江工业大学机械工程学院,杭州310023 [4]浙江工业大学理学院,杭州310023

出　　处：《机械工程学报》2024年第21期387-396,共10页Journal of Mechanical Engineering

基　　金：浙江省基础公益研究(LGJ22E050002);国家自然科学基金(U2130122,51975533,U22A20199);装备预研基金教育部联合基金(8091B022215)资助项目。

摘　　要：针对传统激光气体氮化技术在钛合金表面难以大面积加工、易开裂等问题,将激光氮化与仿生织构相结合,提出一种改善钛合金表面耐磨、抗汽蚀性能的仿生结构化激光气体氮化方法。设计制备条纹形、正方形、正三角形和正六边形的仿生结构化表面,并对仿生结构化单元体的显微硬度、微观组织和物相组成进行了详细分析。对比分析整体氮化与结构化氮化试样的耐磨损性能与抗汽蚀性能,并对失效机制进行研究。结果表明:氮化层平均硬度为850 HV_(0.3)、氮化层表层和中部由发达的树枝晶和富氮固溶体组成,物相组成包括α-Ti、TiN及TiN_(x(0<x<1)),氮化层的磨损以磨粒磨损为主,表面结构的变化起到了缓解汽蚀破坏的作用。整体氮化和结构化氮化试样的耐磨性相比基体均提高了3倍左右,正六边形结构氮化试样的摩擦因数和磨损量最低,结构化氮化试样抗汽蚀性能的提升是表面硬度提升和软硬相间的硬度特征共同作用的结果。利用激光氮化复合仿生织构技术有效改善了钛合金表面的抗汽蚀性能和耐磨性能,且制备的氮化层均匀无裂纹产生。In view of the problems of traditional laser gas nitriding,such as difficult to deal with large areas and easy to crack,a bionic structured laser gas nitriding method is proposed to improve the wear and corrosion resistance of titanium alloy surface by combining laser nitriding with texture.The bionic structured surfaces of stripe,square,positive triangle and positive hexagon are designed and fabricated,and the microhardness,microstructure and phase composition of the bionic structured units are analyzed in detail.The wear resistance and cavitation resistance of integral and structured nitriding samples are compared and analyzed,and the failure mechanism is studied.The results show that the average hardness of the nitride layer is 850 HV0.3,and the surface and middle part of the nitride layer are composed of dendrites and nitrogenous solid solution.The phase composition of the nitride layer includesα-Ti,TiN and TiNx(0<x<1).The wear of the nitride layer is mainly abrasive wear,and the change of surface structure plays a role in alleviating the cavitation damage.The wear resistance of the overall nitrided and structured nitrided specimens is about 3 times higher than that of the matrix,and the friction coefficient and wear amount of the nitrided specimens with the regular hexagonal structure are the lowest.The improvement of the cavitation resistance of the structured nitrided specimens is the result of the joint action of the surface hardness increase and the hardness characteristics between soft and hard.The laser nitriding composite biomimetic weaving technology is used to effectively improve the vapor corrosion resistance and wear resistance of the titanium alloy surface,and the prepared nitriding layer was uniform and crack-free.

关 键 词：激光气体氮化 TC4合金 仿生耦合 耐磨性能 抗汽蚀性能 

分 类 号：TG156[金属学及工艺—热处理]