Blf 18 3

The debinded samples were sintered to a density >97% using a high‐temperature bottom loader furnace of type BLF 18/3 (Carbolite/Gero, Germany). The 35vol.% feedstock was sintered for 3 h at 1550 °C and the 40vol.% feedstock was sintered for 15 min at 1530 °C with heating and cooling rates of 5 K min^‐1, respectively. The pre‐sintered samples were fully densified using a hot isostatic press of type QIH‐6 (Asea, Ohio, USA) for 2 h at 1700 °C under argon pressure of 1500 bar with heating and cooling rates of 10 K min^–1. Slight discolorations due to the hot isostatic pressing (HIP) process were removed by heating the HIP treated MAS in air to a temperature of 1200 °C for 2 h.

Debinding of the samples was done using a two‐step debinding protocol. The parts were immersed in water at 40 °C for a minimum of 5 h and dried at 65 °C for a minimum of 3 h afterward. In the second step, the remaining binder was removed by thermal decomposition in an ashing furnace of type AAF (Carbolite/Gero, Germany). The thermal debinding was done with a heating rate of 1 K min⁻¹ and dwelling phases at the critical decomposition temperatures (270, 400, and 600 °C for 1 h each) in air. The debinded samples were sintered to dense and transparent fused silica glass using a high‐temperature tube furnace of type STF16/450 (Carbolite/Gero, Germany) for sintering in vacuum or a bottom loader furnace of type BLF 18/3 (Carbolite/Gero, Germany) for sintering under atmospheric pressure. The parts were sintered either in vacuum (1 × 10^‐1 mbar) with a dwelling phase at 1320 °C for 2 h or under atmospheric air pressure with dwelling phases at 1250 and 1320 °C for 2 h each. Heating and cooling rates of 3 K min⁻¹ were used, respectively, for both sintering protocols.

The organic binder matrix of the green parts was removed in an ashing furnace of type AAF (Carbolite Gero, Germany). Afterward, the debinded parts were sintered to a density >97 % in a high‐temperature furnace type BLF 18/3 (Carbolite Gero, Germany) with a heating rate of 5 °C min⁻¹ to a maximum temperature of 1550 °C and a dwell time between 1 and 3 h, depending on the thickness of the printed parts.