The Property Characterization of α-Sialon/Ni Composites Synthesized by Spark Plasma Sintering

Abstract

This study investigates the effect of micron-sized nickel particle additions on the microstructural, thermal, and mechanical property changes of α-sialon ceramic composites. The α-sialon/Ni composites were synthesized with an increasing amount of Ni (10–40 wt.%) using the spark plasma sintering technique and nanosized alpha precursors at a relatively low synthesis temperature of 1500 °C with a holding time of 30 min in each case. The density of the samples increased with the increase in Ni content of up to 15 wt.% and, with the further increase in Ni content, it became almost constant with a slight decrease. Furthermore, thermal conductivity and thermal expansion properties of Ni-sialon composites improved slightly with the inclusion of 10 wt.% Ni. The addition of Ni to α-sialon matrix resulted in a decrease in the hardness of the composites from HV10 21.6 to HV10 16.3, however the presence of Ni as a softer interfacial phase resulted in a substantial increase in the fracture toughness of these composites. Fracture toughness was found to increase by approximately 91% at 40 wt.% Ni addition.

Spark Plasma Sintering of SiAlON Ceramics Synthesized via Various Cations Charge Stabilizers and Their Effect on Thermal and Mechanical Characteristics

“…As shown in the densification plot of spark plasma sintered samples (Figure 1), the evolution of SiAlON phases was observed to take place in the range of ~1000-1500 • C. The solution-precipitation process initiated at around ~1200 • C and continued until almost 1500 • C. Similar observation has been reported in previous studies [13,19,28,66]. It is believed that the nitride powders reacted with the oxide precursors to form the oxynitride eutectic liquid phase, which facilitated the densification of SiAlON ceramic.…”

“…Due to the short process time and fewer processing steps it requires, this approach is considered as an energy-saving technology [25,26]. The prominent characteristics of the SPS process include localized generation of plasma, focused plasma-material interaction, and uniform yet fast heating and cooling of the sample [11,12,16,17,[27][28][29][30][31]. Synthesis of a variety of new ceramic materials such as WC-Co, C 3 N 4 -ZrB 2 -SiC, TiC-Si 3 N 4 , TiC-ZrN-C, TiB 2 -hBN, and TiC-SiC w -WC n via SPS technology have been reported in literature [32][33][34][35][36][37].…”

Evaluation of alumina reinforced oil fly ash composites prepared by spark plasma sintering

“…The maximum value of thermal conductivity (27.9 W/m·K) at room temperature is in case of 5 wt.% OFA in a nanosized alumina matrix. Thermal conductivity depends on voids, interface resistance, and particle size of fillers and matrix . Conversely, the thermal expansion decreased as OFA was incorporated into either matrix, (Table ) and this tends to increase with more OFA amount.…”

“…Thermal conductivity depends on voids, interface resistance, and particle size of fillers and matrix. 51,52 Conversely, the thermal expansion decreased as OFA was incorporated into either matrix, ( 3.…”

Sialon and Alumina Modified UV-Curable Coatings with Improved Mechanical Properties and Hydrophobicity

“…Our investigations allow us to compare the photocuring and physical behaviour of systems filled with Sialon and aluminum oxide and can help to design formulations and conditions for industrial applications. Sialon and Alu C compounds are assumed to be potential for used in the engineering of ceramic materials because of their excellent mechanical and thermal properties [25,26]; these fillers can be used for UV-curable polyacrylate-based composites for protective coatings, particularly in the woodworking industry. Light-cured coatings containing Sialon and Alu C have significant advantages over conventional production methods due to their broad properties, such as the material's short curing time and low space requirements.…”