The isothermal reduction of iron oxide pellet fines–carbon composites was investigated at temperatures of 900–1100 °C. The reduction reactions were monitored using the thermogravimetric (TG) technique. Alternatively, a Quadruple Mass Spectrometer (QMS) analyzed the CO and CO₂ gases evolved from the reduction reactions. The effect of temperature, carbon source, and reaction time on the rate of reduction was extensively studied. The phase composition and the morphological structure of the reduced composites were identified by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The results showed that the reduction rate was affected by the temperature and source of carbon. For all composite compacts, the reduction rate, as well as the conversion degree (α) increased with increasing temperature. Under the same temperature, the conversion degree and the reduction rate of composites were greater according to using the following carbon sources order: Activated charcoal > charcoal > coal. The reduction of the different composites was shown to occur stepwise from hematite to metallic iron. The reduction, either by activated charcoal or charcoal, is characterized by two behaviors. During the initial stage, the chemical reaction model (1 − α)⁻² controls the reduction process whereas the final stage is controlled by gas diffusion [1 − (1 − α)^1/2]². In the case of reduction with coal, the reduction mechanism is regulated by the Avrami–Erofeev model [−ln (1−α)²] at the initial stage. The rate-controlling mechanism is the 3-D diffusion model (Z-L-T), namely [(1−α)^−1/3−1]² at the latter stage. The results indicated that using biomass carbon sources is favorable to replace fossil-origin carbon-bearing materials for the reduction of iron oxide pellet fines.

Composite materials, such as aluminum alloy FGMs, provide advantageous weight reduction properties compared to homogenous pure structures while still preserving sufficient stiffness for diverse applications. Despite various research on drilling simulation concepts and ideas for these materials, there still needs to be an agreement on the process modeling. Researchers have looked into a lot of different numerical methods, including Lagrangian, Eulerian, arbitrary Lagrangian–Eulerian (ALE), and coupled Eulerian–Lagrangian (CEL), to find solutions to problems like divergence issues and too much mesh distribution, which become more of a problem at higher speeds. This research provides a global analysis of bottom-up meshing for eleven 1 mm layers using ABAQUS^® software. It combines the internal surface contact approach with the Lagrangian domain’s kinematic framework. The model uses the Johnson–Cook constitutive equation to precisely predict cutting forces, stress, and strain distributions, optimizing cutting parameters to improve drilling performance. According to Taguchi analysis, the most favorable parameters for reducing cutting force and improving performance are a rotational speed of 700 rpm, a feed rate of 1 mm/s, and a depth of cut of 3 mm. The findings suggest that increasing the feed rate and depth of cut substantially affects the cutting force, while the rotational speed has a comparatively little effect. These ideal settings serve as a foundation for improving FGM drilling efficiency.