Thermally annealed biochar assisted nanofluid as quenchant on the mechanical and microstructure properties of AISI-1020 heat-treated steel—a cleaner production approach

To improve the mechanical and microstructure properties of low carbon steel (AISI 1020), a thermally annealed biochar (TAB)-aided quenchant was used in this study. The primary goal of this research was to see how effective it was to use a low-cost, thermally conductive (10³S/m) annealed biochar to improve the mechanical and microstructure of a quench hardened steel workpiece as a quenchant. The quenching procedure was carried out in this analysis with pure distilled water and 0.25, 0.5wt% annealed biochar dispersed distilled water nanofluids. The quenched sample with 0.25wt% biochar nanofluid had a faster cooling rate, lower surface roughness, and a higher hardness value from the center to the edges, according to the findings. Similarly, the specific wear rate and coefficient of friction (COF) of 0.25wt% biochar-aided quenchant are 0.0058mm³/Nm and 0.44, respectively. Furthermore, the martensite microstructures in the 0.25wt% biochar nanofluid quenched workpiece are more refined than the distorted martensite in the 0.5wt% biochar nanofluid quenched workpiece. These low-cost, high-performance, and environmental friendly nanofluids made with annealed biochar may be a cheaper alternative to nanofluids made with other high-cost carbon allotropes like carbon nanotubes (CNTs), graphene, and fullerene.