摘要
使用Nd∶YAG激光器在H13钢表面制备了Ni基涂层,采用扫描电镜、能谱仪、X射线衍射仪及摩擦磨损试验机,研究了涂层组织形貌、物相组成和耐磨性能。结果表明,涂层由细小树枝晶和共晶组成。树枝晶主要由γ-Ni固溶体组成,而共晶相由M_(23)C_6、M_7C_3、Ni_3Fe、Ni_3B等组成。涂层表面相对于其他区域,晶粒更为细小且晶粒方向性消失。涂层平均硬度(HV_(0.2))为708.4,是淬火回火态H13钢的1.60倍。不同磨损条件下,激光熔覆层耐磨性能皆优于H13钢;并随载荷、转速增加,涂层表现出更好的耐磨性能。磨损试验表明,涂层主要为磨粒磨损并伴随少量粘着磨损,H13钢主要为粘着磨损并伴随少量磨粒磨损。
Ni-based alloy coatings were fabricated on H13 steel substrate by Nd： YAG laser cladding methods. The microstructure, phase constitutions and wear resistance of the coating were investigated by means of scanning electron microscope （SEM）, energy dispersive spectrometer （EDS）, X-ray diffrac- tion （XRD） and abrasion testing machine. The results reveal that, Ni-based alloy coating is dense with absence bf obvious holes and cracks, which is mainly composed of fine dendrites and eutectics. The den- drites are composed of 7-Ni, and the eutectic crystal is composed of M_23C_6 , M_7C_3 , Ni_3Fe, Ni_3B. Compared with other regions of coating, the grain size of surface is the finer and the grain orientation disap- pears. The average microhardness of Ni-based alloy coating reaches 708.4 HV_0.2, which is 1.60 times higher than that of quenched and tempered H13 steel. With the increase of load and sliding speed of ab- rasion testing machine, the wear resistance of the coating is superior to that of H13 steel. In process of wear, the wear of coating exhibits mainly abrasive wear accompanied with a small amount of adhesive wear, while the H13 steel wear is mainly characterized by adhesive wear accompanied with a small a- mount of abrasive wear.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2016年第7期690-693,共4页
Special Casting & Nonferrous Alloys
基金
重庆市高校模具技术重点实验室开放课题(MT201505)
关键词
H13钢
激光熔覆
NI基涂层
显微组织
耐磨性能
H13 Steel, Laser Cladding, Ni-Based Alloy Coating, Microstructure, Abrasion Resistance
