ABSTRACT

In this work, multi-walled carbon nanotubes reinforced Cu–Ni matrix (Cu–Ni-MWCNTs) composite coatings were produced using the electro-codeposition method by adding different concentrations of MWCNTs (0.05, 0.1 and 0.15 g L⁻¹) to the Cu–Ni plating bath. To achieve effective dispersion of the MWCNTs, the plating solution was stirred using an ultrasonicator (20 kHz and 500 W) for 120 min. Cu–Ni-MWCNTs composite coatings were characterised by scanning electron microscopy and X-ray diffraction to study the surface morphology and microstructure of the coatings. In addition, the effects of MWCNTs on the microhardness, wear resistance and electrical conductivity of the coating were investigated by microhardness tester, pin on disk wear tester and four-point probe system respectively. All Cu–Ni-MWCNTs composite coatings showed enhanced microhardness and wear performance as compared to the Cu–Ni coating. The Cu–Ni-MWCNT (0.15 g L⁻¹) composite coating exhibited maximum microhardness of 438 HV and minimum wear loss of 0.9 mg among all the coatings, in the same pin-on-disk test conditions, which is attributed to the combined effect of microstructural refinement, higher content of MWCNTs and superior properties of MWCNTs. Electrical studies reveal that MWCNTs play a vital role in increasing electrical conductivity by 1.21 times of magnitude.

摘要

在这项工作中，通过电共沉积法，通过添加不同浓度的MWCNT（0.05、0.1和0.15 g L ^-1，）到Cu-Ni电镀液。为了实现MWCNT的有效分散，使用超声仪（20 kHz和500 W）将镀液搅拌120分钟。通过扫描电子显微镜和X射线衍射对Cu-Ni-MWCNTs复合涂层进行了表征，以研究涂层的表面形态和微观结构。另外，分别用显微硬度计，圆盘磨损试验机和四点探针系统研究了多壁碳纳米管对涂层显微硬度，耐磨性和导电性的影响。与Cu-Ni涂层相比，所有Cu-Ni-MWCNTs复合涂层均具有更高的显微硬度和耐磨性能。Cu–Ni-MWCNT（0.15 g L ^-1）在相同的针-盘测试条件下，复合涂层在所有涂层中均表现出438 HV的最大显微硬度和最小的磨损损耗0.9 mg，这归因于微结构细化，更高的MWCNT含量和优异的性能的综合作用的多壁碳纳米管。电学研究表明，MWCNT在将电导率提高1.21倍数量方面起着至关重要的作用。