Microwave cladding: a novel technique for development of a nanostructured wear resistant surfaces
DOI: 10.62564/M4-AS1841
Apurbba Kumar Sharma
Mechanical and Industrial Engineering Department, Indian Institute of Technology Roorkee
Economic impact of friction and wear on a society is huge. They not only contribute to reduction of the product life, but also significantly reduce the productivity while increasing the manufacturing lead time. Therefore, an engineered surface through coatings or other means would lead to decreased friction and wear. The current work aims to present a novel approach, called microwave cladding, to achieve this. Development of wear resistant surfaces using conventional surface engineering techniques such as weld surfacing and laser cladding have their own limitations like high dilution rates, distortion of substrate, high cost and interfacial cracking etc. In other to address the issues associated with the conventional deposition-based processes, a novel surface engineering process, called microwave cladding, has been developed. This emerging electromagnetic radiation-based technique employs principles of microwave hybrid heating (MHH) to develop clads on metallic substrates. A clad developed through microwave cladding exhibits excellent metallurgical bonding with substrate owing to complete melting of the powder particles and partial melting of a thin interfacing layer of the substrate. Convective current at the interface ensures uniform dilution within a thin layer. Uniform heating nature of the MHH and reduced thermal gradient leads to the formation of uniform microstructure with less porosity in the microwave developed clads. Macro and nanostructured clads of different wear resistant materials, including WC10Co & WC12Co, could be developed using the technique. The cladding was accomplished in a multimode home/industrial microwave applicator with an exposure time of ~540 s at 2.45 GHz. Lower value of power and exposure time was required to develop the nanometric while compared to macromatic clads. The wear resistance of the developed clads were found comparable with the clads developed by other methods.
