Effect of microstructure of overlapping regions on the wear/corrosion resistance performance of laser cladded Fe-based amorphous composite coatings

Abstract

The issue of crystallization during the laser cladding process poses a significant challenge to the application of amorphous coatings. In order to explore the practical application of Fe_41.5Co_12.2Cr_7.4Mo_37.3C_0.3B_0.5Y_0.4Al_0.4 (at.%) amorphous composite coatings, this study fabricated coatings with different scanning speeds. The aim was to delve into their crystallization processes and assess the consequential effects on the coatings’ properties. The study revealed that crystallization predominantly occurs in the coatings’ overlapping region, which can be divided into two zones: the overlapping transition zone (OTZ) and the overlapping heat affected zone (OHAZ). The crystallization extent within the OHAZ is higher than in the OTZ, attributable to the disparate cooling rates characteristic of each region. With increasing scanning speed, the OHAZ gradually increases and the OTZ decreases. The coating prepared at 2000 mm/min has excellent corrosion resistance (polarization resistance 10,814.2 Ω$·$cm²) and wear resistance (wear rate (8.88$\pm$0.378)$\times$10^–6 mm³/N$·$m).