摘要
目的改善NiCrAlY涂层微观组织并提高其力学性能。方法采用直接激光沉积方法制备100%NiCrAlY、NiCrAlY+10%Al2O3和NiCrAlY+20%Al2O3三种样件,分别利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、X射线能量色散谱仪(EDS)、电子探针X射线显微分析仪(EPMA),对不同成分样件进行相组成分析、微观组织观察以及元素组成检测,使用维式显微硬度测试计和万能摩擦磨损试验机,分别检测各个涂层的显微硬度和摩擦系数。结果在NiCrAlY中添加Al2O3后,Al2O3以不规则形状或球形分布在晶内或者晶界处,其尺寸小于2μm。三种复合涂层样件均由γ-Ni和β-NiAl相组成,添加Al2O3陶瓷颗粒后,涂层一次枝晶臂间距均减小,且Ni-Y相显著减少,Y2O3陶瓷颗粒弥散分布在基体的晶内与晶界处。NiCrAlY、NiCrAlY+10%Al2O3和NiCrAlY+20%Al2O3涂层的平均硬度分别为(440.69±30)HV0.2、(482.18±30)HV0.2和(453.09±20)HV0.2,100%NiCrAlY、NiCrAlY+10%Al2O3和NiCrAlY+20%Al2O3涂层的摩擦系数分别为0.77、0.55和0.52。结论加入Al2O3后,基体晶粒有一定程度的细化。在晶粒细化作用以及陶瓷颗粒弥散作用下,涂层的显微硬度有所提高,其中NiCrAlY+10%Al2O3的硬度最高,相比NiCrAlY基体提高了约9.5%。此外,发现添加Al2O3后,NiCrAlY+10%Al2O3和NiCrAlY+20%Al2O3样件的摩擦系数比NiCrAlY样件下降均超过25%,其中NiCrAlY+10%Al2O3样件的磨损量最小,相对于NiCrAlY涂层下降了近13.5%,耐磨性明显改善。
The work aims to improve the microstructure and mechanical properties of NiCrAlY coating.Three kinds of samples,100wt.%NiCrAlY,NiCrAlY+10wt.%Al2O3 and NiCrAlY+20wt.%Al2O3,were prepared by directed laser deposition.X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive X-ray spectrometer(EDS)and electron probe X-ray microanalyzer(EPMA)were used to analyze the phase composition,microstructure and elemental composition of samples with different constituents,respectively.The microhardness and friction coefficient of the samples were measured by Vickers indenter and universal friction and wear tester.After added into NiCrAlY,Al2O3 particles were distributed in an irregular shape or in a sphere within or at grain boundaries with a size less than 2μm.The three composite coating samples were composed ofγ-Ni andβ-NiAl phases.After Al2O3 particles were added,the primary arm spacing of the coating decreased and the Ni-Y phase decreased significantly,and Y2O3 ceramic particles were dispersed in the crystal and grain boundaries of the matrix.The average microhardness and friction coefficients of NiCrAlY,NiCrAlY+10%Al2O3 and NiCrAlY+20%Al2O3 coatings were(440.69±30)HV0.2,(482.18±30)HV0.2 and(453.09±20)HV0.2,respectively and 0.77,0.55 and 0.52,respectively.After Al2O3 particles are added,the matrix grain size is refined to a certain extent,and the microhardness of coatings is improved under the effect of grain refinement and ceramic particle dispersion.In particular,the microhardness of NiCrAlY+10%Al2O3 is the highest,which is about 9.5%higher than that of NiCrAlY matrix.In addition,it is found that the friction coefficient of the coating decreases and the wear resistance increases after Al2O3 particles are added.The friction coefficient of NiCrAlY+10%Al2O3 and NiCrAlY+20%Al2O3 coatings decreases by more than 25%compared with NiCrAlY samples.Among them,the NiCrAlY+10%Al2O3 sample has the smallest wear loss,which is nearly 13.5%lower than that of the NiCrAlY coating,and the wear resistance is obviously improved.
作者
吴东江
刘妮
余超
崔强
牛方勇
马广义
赵凯
WU Dong-jiang;LIU Ni;YU Chao;CUI Qiang;NIU Fang-yong;MA Guang-yi;ZHAO Kai(Key Laboratory for Precision and Non-traditional Machining Technology of Ministry of Education,Dalian University of Technology,Dalian 116024,China;Shanghai Aerospace Equipments Manufacturer Co.,Ltd,Shanghai 200245,China)
出处
《表面技术》
EI
CAS
CSCD
北大核心
2020年第1期203-212,共10页
Surface Technology
基金
国家自然科学基金青年科学基金(51805070)~~
作者简介
通讯作者:马广义(1982-),男,博士,副教授,主要研究方向为激光增材制造、激光焊接。邮箱:gyma@dlut.edu.cn。
