车用ZL205A铝合金激光熔覆Al2O3/NiCrAl涂层组织及摩擦性能研究  

Tribological Behavior of ZL205A Al-Alloy Modified with Laser Cladded Al2O3-Doped NiCrAl Coatings

作　　者：邵海泉[1] Shao Haiquan(College of Automotive Engineering,Henan Polytechnic Institute,Nanyang 473009,China)

机构地区：[1]河南工业职业技术学院汽车工程学院,南阳473009

出　　处：《真空科学与技术学报》2020年第11期1034-1038,共5页Chinese Journal of Vacuum Science and Technology

摘　　要：综合运用Ni/Al和Al2O3粉末并以激光熔覆方法在阀门用ZL205A铝合金上制得耐磨涂层,实验测试研究其微观组织及摩擦性能。研究结果表明:NiCrAl/Al2O3复合涂层形成较为平整表面,得到的熔覆涂层具有均匀的厚度。添加Al2O3陶瓷颗粒后,能够达到细化组织的效果。位于在枝晶间隙区域还有许多白色的小尺寸颗粒,在相邻枝干间形成了由Al、Ti共同组成的微量起伏结构。NiCrAl涂层硬度平均为350 HV,NiCrAl/Al2O3复合涂层达到了650 HV硬度,说明加入Al2O3颗粒后可以获得比原先单一NiCrAl涂层更高显微硬度。与铝合金相比,NiCrAl/Al2O3复合涂层达到了更小的磨损量,并且比NiCrAl涂层减小近30%。NiCrAl/Al2O3复合涂层内存在许多弥散态的Al2O3细小颗粒,对摩擦期间的基体塑性起到抑制作用,对基体发挥明显支撑作用,显著提升涂层耐磨能力。The surfaces of ZL205 A Al-alloy,a good automobile valve material,were modified with the Al2O3-doped NiCrAl coatings synthesize by laser cladding of Ni,Al and Al2O3 powders.The microstructures and tribological properties of the Al2O3-doped NiCrAl and Al2O3-doped NiCrAl coatings were characterized with X-ray diffraction,scanning electron microscopy and conventional mechanical probes.The results show that when it comes to tribological properties,the Al2O3-doped NiCrAl coating outperforms the NiCrAl coating.For example,the Al2O3-doping decreased the friction coefficient,increased the hardness of NiCrAl coatings from 350 to 650 HV and decreased the wear-rate of NiCrAl coatings by 30%,possibly because the randomly distributed well-dispersed Al2O3 particles effectively prevented the growth of dendric textures in laser cladding,resulting in significant reductions of both the grain-size and plasticity of the uniform,smooth and compact Al2O3-doped NiCrAl coatings.

关 键 词：铝合金 激光熔覆 Al2O3/NiCrAl涂层 微观组织 摩擦性能 

分 类 号：TG142[一般工业技术—材料科学与工程]