The Effect of Powder-to-Flux Ratio and Heating Duration on the Microstructure and Corrosion Resistance of WO<sub>3</sub> Nanoparticle-Reinforced Sn–20Bi Coatings on Low-Carbon Steel

The current research introduces a cost-effective thermal coating process using a tinning surfacing technique to synthesize WO<sub>3</sub> nanoparticle-reinforced Sn-20Bi (S20B) alloy coating on low-carbon steel (LCS). A ball-milling machine was used for mechanical mixing and blending of...

Full description

Saved in:
Bibliographic Details
Main Authors: Naglaa Fathy, Mohamed Ramadan, Shereen Mohammad Al-Shomar, Khalid M. Hafez, El-Sayed M. Sherif, Alhulw H. Alshammari, K. S. Abdel Halim
Format: Article
Language:English
Published: MDPI AG 2025-06-01
Series:Crystals
Subjects:
Online Access:https://www.mdpi.com/2073-4352/15/6/551
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The current research introduces a cost-effective thermal coating process using a tinning surfacing technique to synthesize WO<sub>3</sub> nanoparticle-reinforced Sn-20Bi (S20B) alloy coating on low-carbon steel (LCS). A ball-milling machine was used for mechanical mixing and blending of Sn and Bi powders together with 0.25 wt.% WO<sub>3</sub> nanoparticles. The produced powders were mixed with a prefabricated flux in two different ratios to optimize the best surface coating morphology. The synthesized coatings were spread out on the surface of the LCS in a layer of 0.25 g cm<sup>−2</sup> and were heated for 3, 4, and 5 min at 370 °C. A series of corrosion tests was carried out to understand the effect of the different S20B and S20B-WO<sub>3</sub> coatings on the corrosion passivation of the LCS samples in 3.5% NaCl solution. The coating surface layer thickness increased by decreasing the percentage of flux in the synthesized coating. Increasing the heating time (from 3 min to 5 min) increases surface coating uniformity and slightly boosts the average Fe−Sn intermetallic (IMC) layer thickness (from 1.7 ± 0.3 µm to 3.3 ± 0.3 µm). By incorporating 0.25 wt.% WO<sub>3</sub> nanoparticles into the S20B coating surface layer, a uniform microstructure was achieved and the thickness of the Fe–Sn IMC layer was reduced to 2.6 ± 0.3 µm. This study found that the presence of WO<sub>3</sub> nanoparticles significantly improved the corrosion resistance of S20B-coated LCS. These results demonstrate that adding a small of WO<sub>3</sub> nanoparticles significantly enhances the microstructural integrity and corrosion resistance of S20B coatings on LCS.
ISSN:2073-4352