超高速激光熔覆镍包覆c-BN颗粒增强耐磨复合涂层及摩擦磨损行为  

High-speed Laser Cladding Ni-coated c-BN Particles Reinforced Wear-resistant Composite Coating and its Wear Behavior

作　　者：刘康诚 娄丽艳 蔡志海 邢志国 王海斗 李成新[1] LIU Kangcheng;LOU Liyan;CAI Zhihai;XING Zhiguo;WANG Haidou;LI Chengxin(State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an 710049,China;National Engineering Research Center for Mechanical Product Remanufacturing,Academy of Armored Forces Engineering,Beijing 100072,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049 [2]陆军装甲兵学院机械产品再制造国家工程研究中心,北京100072

出　　处：《中国表面工程》2024年第5期337-345,共9页China Surface Engineering

基　　金：国家自然科学基金(52130509)。

摘　　要：钛合金拥有较轻的密度和较高的比强度被广泛应用在航空航天以及航海等领域。然而,较差的耐磨性限制了其在各种工况下的应用。为提升钛合金在极端服役条件下耐磨性能,采用超高速激光熔覆工艺在高温钛合金表面成功制备出完整、致密的镍包覆c-BN复合耐磨涂层。利用XRD、SEM、EDS和显微硬度计、摩擦磨损试验机等手段分析测试涂层微观组织形貌、物相组成和力学性能。结果显示,c-BN颗粒在激光照射下部分分解,并与熔池中的Ti反应,原位生成TiN、TiB等增强相;另外在涂层凝固过程中,c-BN表面包覆的镍进入Ti晶格并部分与Ti反应生成Ni-Ti金属间化合物,对涂层起到固溶强化和弥散强化,使得镍包覆的c-BN涂层硬度和耐磨性能相较于钛合金基体和未包覆镍的c-BN涂层均显著提升:涂层平均硬度值在1200 HV0.3以上,达到钛合金基体3倍以上;经过摩擦磨损试验后,其磨损体积相较于钛合金基体和未包覆镍c-BN涂层分别减少72%和22%。磨损形貌显示,钛合金基体表现出明显的黏着磨损,未包覆镍的c-BN涂层表现为磨粒磨损;而镍包覆的c-BN涂层磨痕则出现大量“鱼鳞”状磨屑。研究采用镍包覆的方式在熔覆前将c-BN颗粒包裹,使得c-BN陶瓷粉末流动性提升,并进一步增强复合涂层的显微硬度,从而提升复合涂层的耐磨性能。Titanium alloys are widely used in aerospace and marine industry because of their low density and high specific strengths.However,their low hardness and poor wear resistance limit their application under various working conditions.Coating is an effective and rapid surface modification method that can improve the wear resistance of titanium alloys under extreme service conditions.In this study,a complete and dense c-BN(cubic boron nitride)composite wear-resistant coating was successfully applied on the surface of titanium alloy using a novel ultra-high-speed laser cladding method.To enhance the mobility of the c-BN ceramic powder,it was coated with Ni via electroless plating,and the effects of Ni coating on the microstructure and wear performance of the coating were comparatively studied.The microstructure,phase composition,and mechanical properties of the coatings were analyzed using an XRD/SEM/EDS microhardness tester and a friction wear tester.The results showed that the c-BN particles partially decomposed under laser irradiation and reacted with Ti in the molten pool to generate TiN,TiB,and other reinforced phases in-situ.In addition,in c-BN(Ni)coatings,the Ni coating on the c-BN surface melted under laser irradiation and entered the Ti lattice or partially reacted with Ti to generate Ti-Ni intermetallic compounds in the molten pool during solidification.This strengthened the solid solution and dispersion of the coating.Thus,the microhardness of the c-BN(Ni)coatings was significantly improved compared to that of the titanium alloy and c-BN coatings without Ni coating.Furthermore,the average microhardness of this coating was more than 1200 HV0.3,which is more than three times that of the titanium alloy.After etching,for both the c-BN coatings,the top of the coating was mainly TiN,and the bottom of the coating was fine TiB;furthermore,the middle of the coating contained mix of TiN and TiB.The results of friction wear tests using Si_(3)N_(4)as a counter-abrasive pair showed that these reinforced phases produced a

关 键 词：超高速激光熔覆 钛合金 表面改性 摩擦 

分 类 号：TB333[一般工业技术—材料科学与工程]