A Comparative Evaluation and a Benefit Assessment of Sintering α‐Al 2 O 3 in Induction and Conventional Furnaces

This work provides a quantitative comparison of induction heating and conventional resistance‐furnace sintering for the processing of high‐purity α‐Al 2 O 3 ceramics, focusing on thermal behavior, energy efficiency, and sintering quality. The study combines experimental characterization of sintering samples and analysis of thermal curves. Here is also covered an energy‐based modeling to propose a microstructural development, heating behavior, and overall energy demand for induction and conventional resistance furnaces. The materials used in this work are commercial alumina (as‐received) and milled powder to isolate the effect of the heating method, with a mechanically milled condition. We also examined its influence on microstructure. The samples sintered by induction heating achieved a maximum relative density of ∼98.2% and a Vickers hardness of 2060 ± 22 HV at 1500°C for milled alumina powder, compared to 1980 ± 28 HV and 97.1% relative density for conventional sintering under identical conditions. Thermal simulations in a Matlab‐based finite differences methods (FDM) model reveal that resistance‐furnace heating is dominated by slow radiative and convective fluxes, leading to a slower achievement of a homogeneous temperature distribution, which in practice means the system takes longer to equilibrate. In induction heating, the sintering starts in the first few minutes and the pellet edges exhibit a more pronounced temperature rise. However, this condition diminishes rapidly, and within a short time the temperature distribution becomes homogeneous, achieving uniformity significantly faster than in a conventional furnace. Energy analysis shows that induction reduces total cumulative electrical consumption by 92.37% relative to the furnace at the highest target temperature evaluated (1500°C).