Low-temperature synthesis of AlN powder with multicomponent additive systems by carbothermal reduction–nitridation method

Effects of Milling pH and Hydrothermal Treatment on Formation of Nanostructured Boehmite Binder for Alumina Extrusion

“…The presence of this aluminum trihydroxide was confirmed by FTIR spectroscopy (Figure 2(b)). The absorption bands at 3370, 3425, 3470, 3547, 3620, and 3654 cm −1 were assigned as vibration frequencies of the OH stretching modes of -Al(OH) 3 and are in accordance with reported FTIR spectrum data for bayerite [22][23][24][25].…”

“…No significant differences were observed between the powders milled under different pH conditions (acidic, acidic-basic, and basic medium) when analyzed by SEM (Figures 1(b)-1(d)). However, XRD analysis and FTIR spectroscopy revealed that the powder milled under acidic (pH 4.0-4.2) condition had only -Al 2 O 3 phase (ICSD 85137), as the starting powder, while the powders milled under acidic-basic (pH 4.1-8.4) and basic (pH 9.2-10.3) conditions presented small fractions of bayerite [ -Al(OH) 3 , ICSD 38108], in addition to -alumina (Figure 2(a)). The presence of this aluminum trihydroxide was confirmed by FTIR spectroscopy (Figure 2(b)).…”

“…Among the several actions that may contribute to achieving the abovementioned goals, the use of low-toxicity materials and recycling plays a major role [1]. With regard to ceramic processing, environmental impacts may be reduced in many ways, such as the development of rapid sintering processes, new additives to decrease the temperature of powder synthesis, replacement of toxic organic solvents used in forming methods (such as tape casting and powder injection molding) by aqueous systems, development of manufacturing routes with fewer steps, and elimination or reduction of organic binders (e.g., PVA, PEG, PMMA, and PVB) [2][3][4].…”

Carbothermal synthesis of spherical AlN granules: Effects of synthesis parameters and Y2O3 additive

“…Also, it purifies the AlN lattices by forming YAP and YAM with low activity of Al 2 O 3 in them, which favors for oxygen removal and thus improves the thermal conductivity of AlN ceramics [21][22][23]. Furthermore, the efficiency of Y 2 O 3 additive on the carbothermal synthesis of AlN powders has also been demonstrated by several researchers [24][25][26][27]. It was expected that Y 2 O 3 was beneficial for enhancing the reactivity of Al 2 O 3 powders and thus decreasing the synthesis temperature of CRN process.…”

Processamento, propriedades e aplicações das cerâmicas de nitreto de alumínio

“…Dependendo da temperatura de síntese, os dois processos (RCN ou ND) podem resultar em pós de AlN com significativo residual de segundas fases oriundas das adições de agentes catalizadores. Deste modo, pode-se obter pós de AlN pré-aditivados, o que elimina a necessidade do uso de aditivos de sinterização [32].…”