化学镀Ni⁃P及Ni⁃W⁃P镀膜组织及性能对比研究

Comparative Study on Microstructure and Properties of Electroless Ni⁃P and Ni⁃W⁃P Coatings

为了更好地了解化学镀Ni⁃P及Ni⁃W⁃P 2种镀膜的优缺点,利用X射线衍射仪、光学显微镜、电化学工作站以及维氏硬度计等测试分析手段对化学镀Ni⁃P和Ni⁃W⁃P镀膜镀态及热处理态显微组织、结合力、硬度和耐特定工况腐蚀性能进行对比研究。结果表明:2种镀膜均与基体形成良好结合且厚度均匀,镀膜表面胞粒堆垛致密,具有一定方向性且大小均匀,镀膜孔隙率低;Ni⁃W⁃P镀膜初始晶化的热处理温度较Ni⁃P镀膜低;在镀膜硬度超过800 HV_(3N)后,Ni⁃W⁃P镀膜较Ni⁃P镀膜表现出更好的韧性;且Ni⁃W⁃P镀膜在特定工况腐蚀环境下具有更好的耐蚀性。

In order to better understand the advantages and disadvantages of electroless Ni⁃P and Ni⁃W⁃P coatings,X⁃ray diffractometer,opti⁃cal microscope,electrochemical station,Vickers hardness tester and other test and analysis methods were used for the comparative study on the microstructure,adhesion,hardness and the corrosion resistance in particular working conditions of electroless Ni⁃P and Ni⁃W⁃P coatings in as⁃plated and heat⁃treated statuses.Results showed that the adhesion of two coatings with the substrate was good and both coatings had uni⁃form thickness.The coatings showed well packed homogenous cells on their surfaces with a certain directionality and low porosity.The Ni⁃W⁃P coating started to crystallize at a lower heat treatment temperature than Ni⁃P coating.Besides,the Ni⁃W⁃P coating presented better ductility than Ni⁃P coating when the hardness of the coatings was higher than 800 HV_(3N).Meanwhile,the Ni⁃W⁃P coating had better anticorrosion prop⁃erty under certain corrosive service conditions.