Enhancing composite materials through fly ash reinforcement through powder metallurgy

• Published in: Materials chemistry and physics 2023-10, Vol.307, p.128124, Article 128124
• Main Authors: da Motta, Clayton André Oliveira, de Souza, José, Martins, Vinícius, Shaeffer, Lirio, Rossini, Elton Gimenez, Biehl, Luciano Volcanoglo, de Jesus Pacheco, Diego Augusto, Damas Martins, Carlos Otávio, Medeiros, Jorge Luis Braz
• Format: Article
• Language: English
• Subjects: Fly ash; Mechanical behavior; Mechanical properties; Metallic composites; Powder metallurgy
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2023.128124

The utilization of fly ash as reinforcement in composites offers a cost-effective alternative for applications involving ductile metallic matrices. Ash is a by-product of coal combustion in thermoelectric plants, and its use can serve as an environmentally friendly option. Fly ash exhibits characteristics of a ceramic material. However, there are gaps in understanding the mechanical and metallurgical behavior resulting from the interaction between the matrix and the fly ash-based reinforcement. This study aims to develop and evaluate the application of various amounts of fly ash as reinforcement in metal matrix composites through the powder metallurgy process. The process adheres to internationally recognized standards for incorporating ashes into metallic composites. The method involved producing specimens with no fly ash (0FA) and using 5%, 10%, and 15% fly ash (5FA, 10FA, 15FA). The samples were assessed for density, microstructure, microhardness, and wear coefficient using established techniques. Through graphical and statistical analyses, the research examined the impact of reinforcements on the metallic matrix. The results indicate that including fly ash as a composite reinforcement led to a reduction in density with a variance level of F′ 17.7. The microhardness values were not significantly affected, with F′ 0.46. There was a noticeable improvement in wear resistance for 200 cycles (F′ 22.7), 400 cycles (F′ 4.7), and 600 cycles (F’ 0.58). In conclusion, employing composites reinforced with fly ash of varying compositions is feasible, using highly applied compressive pressures and the powder metallurgy process. [Display omitted] •Fly ash composites show comparable properties to ash-free composites.•Mechanical strength and dimensional stability of composites resemble the unreinforced matrix.•Fly ash exhibits lower post-sintering density, indicating enhanced matrix-reinforcement interaction.•Fly ash content above 5% as reinforcement is a feasible option for metallic matrix composites.•The research contributes novel insights to the field of powder metallurgy technology.