TY - GEN
T1 - Grain growth of β-Si3N4 using Y 2O3 and Al2O3 as sintering aids
AU - Ceja-Cárdenas, Leonel
AU - Lemus-Ruiz, José
AU - De La Torre, Sebastián Díaz
AU - Bedolla-Becerril, Egberto
PY - 2012
Y1 - 2012
N2 - The mechanical properties of silicon nitride ceramics are closely linked to the α-β phase transformation. Spark plasma sintering (SPS) technique has been used to density pure α-Si3N4 commercial powder, using Y2O3 and Al2O3 as additives; from 2.5 and 5.0 wt% and 1.5 and 3 wt%, respectively. Such powder admixtures were previously spray-dried at 160°C in such a way that powder was thoroughly homogenized. The sintering treatment included: 3 to 20 min holding time, 38 MPa axial load, sintering temperature of 1500°C and heating rate of 300°C/min. The maximum relative density developed on studied specimens is nearly 99% of theoretical value, which corresponds to 2M-series specimens and could only be attained once the β-phase nucleated from the α-silicon nitride matrix. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses confirmed the presence of two mains phases in the resultant microstructures: α- and β-Si3N4. Both the β-Si3N4 grain growth and the role that different amount of additives can play during SPS-sintering are analyzed.
AB - The mechanical properties of silicon nitride ceramics are closely linked to the α-β phase transformation. Spark plasma sintering (SPS) technique has been used to density pure α-Si3N4 commercial powder, using Y2O3 and Al2O3 as additives; from 2.5 and 5.0 wt% and 1.5 and 3 wt%, respectively. Such powder admixtures were previously spray-dried at 160°C in such a way that powder was thoroughly homogenized. The sintering treatment included: 3 to 20 min holding time, 38 MPa axial load, sintering temperature of 1500°C and heating rate of 300°C/min. The maximum relative density developed on studied specimens is nearly 99% of theoretical value, which corresponds to 2M-series specimens and could only be attained once the β-phase nucleated from the α-silicon nitride matrix. X-ray diffraction (XRD) and scanning electron microscope (SEM) analyses confirmed the presence of two mains phases in the resultant microstructures: α- and β-Si3N4. Both the β-Si3N4 grain growth and the role that different amount of additives can play during SPS-sintering are analyzed.
UR - http://www.scopus.com/inward/record.url?scp=84867903849&partnerID=8YFLogxK
U2 - 10.1002/9781118486955.ch7
DO - 10.1002/9781118486955.ch7
M3 - Contribución a la conferencia
SN - 9781118273753
T3 - Ceramic Transactions
SP - 71
EP - 77
BT - Advances in Sintering Science and Technology II - A Collection of Papers Presented at the International Conference on Sintering 2011
PB - American Ceramic Society
T2 - International Conference on Sintering 2011
Y2 - 26 August 2011 through 1 September 2011
ER -