Microstructure characteristics of NiCrBSi/WC coatings on medium-Ni-Cr infinite chilled cast iron by laser cladding

作者：Chen, Chang-jun; Zhang, Min^*; Liu, Xing; Wang, Xiao-nan

来源：International Journal of Surface Science and Engineering, 2016, 10(2): 162-178.

DOI：10.1504/IJSURFSE.2016.076513

• medium-Ni-Cr infinite chilled cast iron
• laser cladding
• microstructure
• WC
• NiCrBSi
• wear

Thick composite coatings of tungsten carbides (WC) in a metal matrix are ideal for components subjected to heavy abrasive wear. Laser cladding NiCrBSi/WC composite layers were produced on medium-Ni-Cr infinite chilled cast iron substrates with a continuous wave (CW) CO2 laser using the powder delivering technique. Different substrate temperature was selected during the cladding process. And the optimised preheat temperature was 300 degrees C. Microhardness of the cladding layers was measured and the microstructure was characterised by optical microscope (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The chemical composition of the coating was analysed by the energy dispersive X-ray analysis (EDAX) equipped in the SEM machine. The results show that over 0.5 mm thickness, fully dense and crack-free cladding layers of NiCrBSi/WC can be formed on medium-Ni-Cr infinite chilled cast iron substrate. Average microhardness values of the metal matrix composite coating is as high as 900 HV, while the substrate is only 500 HV. The pin-on-plate wear tests showed the wear resistance of the cladding layer is substantially higher than that of the untreated substrate.

• 出版日期2016
• 单位苏州大学