摘要
利用大功率激光在1Cr18Ni9Ti表面熔覆NiCrBSi涂层,采用SEM、EDS和MM2000磨损试验机研究了不同激光功率下熔覆层的显微组织、成分及磨损特性。结果表明,熔覆层由熔覆区和结合区两部分组成,熔覆区主要有γ-(Ni,Fe)、CrB等多种相结构,呈现出树枝晶、不规则颗粒状、针状及共晶形式等多种形貌。结合区为细小柱状晶,激光功率增大,稀释率增大。熔覆层的磨损为磨粒磨损和粘着磨损共同作用的结果,磨损率分布在(2.2～2.6)×10^(-5)mm^3/m.N之间,平均摩擦系数为0.52。激光功率增加,耐磨性下降。EDS分析表明主要元素Ni、Fe、Cr、Si在熔覆层中均匀分布。高功率激光熔覆层中,Fe含量所占比重明显增加。
Laser cladding of NiCrBSi coatings on 1Cr18Ni9Ti stainless steel were obtained by high power laser. Microstructure, composition distribution and wear properties of the as-ctadded coatings by different laser power were investigated using SEM, EDS and MM-2000 wear resistance machine. The results show that the coating can be characterized as two regions, cladding and bonding zones. The cladding zone consists of multiple phases such as γ-（Ni,Fe） and CrB, which presenting several morphologies： dendritic, eutectic, irregular granulated and needle-like structures. The bonding zone was mixed by NiCrBSi and substrate alloy, mainly made up of columnar grains. Dilution increased with the increase of laser power. The wear test results show that wear mechanism of the overlap-cladded coatings are abrasive wear and adhesive wear. The wear rate is in the range of （2.2-2.6） × 10^-5 mm^3/m. N and the average friction coefficient is 0.52. The wear resistance decreased when increasing laser power. EDS analysis indicates that the main constitutional compositions of Ni, Fe, Cr and Si homogeneously distribute in the coatings. The content of Fe was apparently improved in the higher laser power cladded coatings.
出处
《应用激光》
CSCD
北大核心
2010年第3期173-177,共5页
Applied Laser
基金
国防科技重点实验室09基金项目
关键词
激光熔覆
镍基合金
显微组织
磨损特性
laser cladding
Ni-based alloys
microstructure
wear resistance properties
