摘要
目的研究铝含量对内生氧化铝颗粒增强高熵复合涂层的组织结构及其摩擦学性能的影响。方法在激光熔覆过程中,利用铝热反应将金属氧化物还原,并沉积在Q235钢表面,制备内生Al_(2)O_(3)陶瓷颗粒增强的Al_(x)CoCrFeNi(x=0,0.3,1,1.5,2)高熵复合涂层。通过XRD、SEM、EDS、XPS、RAMAN及摩擦磨损测试仪等检测方法,研究高熵复合涂层的组织结构及其摩擦学性能。结果涂层中含有大量弥散分布的纳米级Al_(2)O_(3)陶瓷颗粒。随着Al含量的增加,高熵复合涂层逐渐由FCC与BCC共存的形式转变为单相BCC的显微组织。同时,载荷为10 N时,高熵复合涂层的摩擦系数和磨损率均随着Al含量的上升而下降。Al_(2)CoCrFeNi具有最低的平均滑动摩擦系数(0.15)和最低的磨损率(1.01×10^(–6) mm^(3)/(N·m)),分别为Q235钢基体的1/4和1/38。当Al_(x)CoCrFeNi系涂层中,当x增加至2时,磨痕表面的逐层剥落现象消失。涂层的主要磨损形式由氧化磨损和疲劳磨损转变为轻微的磨粒磨损。载荷为20 N时,Al_(2)CoCrFeNi涂层的平均摩擦系数上升至0.325。结论增加复合涂层中Al元素的含量可以稳定BCC相,并细化组织。同时,过量Al元素有抑制Fe元素氧化、降低摩擦表面Fe_(2)O_(3)含量、提高Fe_(3)O_(4)含量的作用,从而显著降低复合涂层的摩擦系数,并提高其减摩和耐磨性能。
This paper is to study the effect of Al content on the microstructure and tribology performance of high-entropy composite coating reinforced by endogenous alumina particles.In the process of laser cladding,metal oxides were reduced and deposited on the surface of Q235 steel by thermite reaction to prepare Al_(x)CoCrFeNi(x=0,0.3,1,1.5,2)high-entropy composite coating reinforced by endogenous Al_(2)O_(3) ceramic particles.XRD,SEM,EDS,XPS,RAMAN,friction test and other experimental methods were used to study the microstructure and tribology performance of the high-entropy composite coatings.The results show that there are dispersed nano-sized Al_(2)O_(3) ceramic particles in the coating.With the increase of Al content,the microstructure of the high-entropy composite coating gradually changes from FCC and BCC coexistence to BCC single phase.At the same time,the friction coefficient and wear rate of the high-entropy composite coating under 10 N load decreased with the increase of Al content.Al_(2)CoCrFeNi has the lowest friction coefficient(0.15)and the lowest wear rate(1.01×10^(-6) mm^(3)/(N·m)),which are 1/4 and 1/38 of the base Q235 steel respectively.When x in Al_(x)CoCrFeNi coating increases to 2,the peeling phenomenon of the wear scar surface disappears.The main wear form of the coating changes from oxidative wear and fatigue wear to slight abrasive wear.The average friction coefficient of Al_(2)CoCrFeNi coating increased to 0.325 under a load of 20 N.Increasing the Al element in the composite coating can stabilize the BCC phase and refine the structure.At the same time,excessive Al element can inhibit Fe element oxidation and increase the content of Fe_(3)O_(4) on the surface of the wear scar,thereby significantly reducing the friction coefficient of the composite coating and improving its friction reduction and wear resistance.
作者
唐秋逸
纪秀林
段峻
王辉
张映桃
TANG Qiu-yi;JI Xiu-lin;DUAN Jun;WANG Hui;ZHANG Ying-tao(College of Mechanical&Electrical Engineering,Hohai University,Changzhou 213022,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2021年第11期218-225,242,共9页
Surface Technology
基金
国家自然科学基金(51875169,51475140)。
作者简介
唐秋逸(1996-),男,硕士研究生,主要研究方向为高熵合金涂层。;通讯作者:纪秀林(1975-),男,博士,教授,主要从事表面技术与摩擦学方面的研究。
