Thermal Stability of Calcium α-sialon Ceramics

The Relationship between the Spark Plasma Sintering Temperature and Mechanical Properties of Combustion-Synthesized α- and β-SiAlON

“…Comparing the two α-SiAlON powders, the α to β transformation ratio is higher for Y-α-SiAlON than for Ca-α-SiAlON. This result agrees with the report by Hewett et al 13) , which described that Ca-α-SiAlON showed thermal stability superior to α-SiAlONs with added rare-earth elements.…”

Thermal properties of the nitrogen-rich Ca-α-Sialons

“…no ␣ to ␤ phase transformation takes place in these samples. In contrast, most ␣-Sialons stabilized by rear earth cations are prone to transform into ␤-Sialon and grain boundary phases in the temperature region 1300-1600 • C. [15][16][17][18] This finding, together with the findings by Hewett et al 12 and Mandal and Thompson 13 , that oxygen-rich Ca-␣-Sialons are stable even when sintered with excess glass phase, indicates that calcium stabilized ␣-Sialons is probably the most thermal stable Sialon phase over a wide composition and temperature range. Low oxygen contents of starting compositions often yield less amounts of grain boundary glass phase in the sintered body, and the formed grain boundary phase has, due to its higher nitrogen content, higher viscosity than an oxygen-rich grain boundary phase.…”

Ca-α SiAlON hollow spheres prepared by carbothermal reduction–nitridation from different SiO2 powders

“…SiAlON, a-and b-SiAlON, have been well known as representative groups in engineering ceramics because of their high hardness, excellent wear and corrosion resistance in severe environment [1][2][3][4]. a-SiAlON is a solid solution of the a-Si 3 N 4 crystal structure in which metal cations are incorporated as a stabilizer.…”

“…Calcium also has a higher solubility per unit cell in the a-SiAlON lattice, hence the quantity of residual glass in the grain boundary of Ca-a SiAlON ceramics can be less and the formation range of a-SiAlON single phase would be wider compared to a-SiAlONs containing rare-earth elements [2,5]. Furthermore, thermal stability in Ca-a SiAlON is superior to rare-earth stabilized aSiAlON [3]. The toughness of a-SiAlON ceramics can be improved due to the development of Ca-a SiAlON ceramics with elongated grains [1].…”

“…a-SiAlON ceramics have been generally produced from powder mixture of Si 3 N 4 -AlN-M x O y at high temperatures through a liquid phase sintering process [1][2][3][4]6,7]. In order to improve the reliability of a-SiAlON ceramics, it is important to develop homogeneous and fine a-SiAlON powders.…”