Effects of heating rate on alumina grain growth

Abstract

A rapid-heating method in the absence of electric/magnetic field was achieved by introducing a self-propagating-combustion (SHS) as heating source. The effect of heating rate on the alumina grain growth was explored based on this rapid-heating method. Comparing with the alumina prepared by two different heating ratios (greater than 1 000 °C/min in SHS and about 50 °C/min in common pressureless sintering furnace), it was revealed that the rapid heating could promote the grain growth greatly without pressure during sintering. However, if a pressure was applied simultaneously, the grain growth would be almost completely restrained. Since these observations are quite different from the expectation, a new grain growth model was proposed.

Keywords

rapid heating rate / SHS / grain growth

References

[1] Orrù R, Licheri R, Locci A M, . Consolidation/Synthesis of Materials by Electric Current Activated/assisted Sintering[J]. Mater. Sci. Eng. R., 2009, 63(4–6): 127-287.

[2] Munir Z A, Anselmi-Tamburini U, Ohyanagi M The Effect of Electric Field and Pressure on the Synthesis and Consolidation of Materials: a Review of the Spark Plasma Sintering Method[J]. J. Mater. Sci., 2006, 41(3): 763-777.

[3] Anselmi-Tamburini U, Garay J E, Munir Z A Fast Low-temperature Consolidation of Bulk Nanometric Ceramic Materials[J]. Scripta. Mater., 2006, 54(5): 823-828.

[4] Olevsky E A, Froyen L Impact of Thermal Diffusion on Densification during SPS[J]. J. Am. Ceram. Soc., 2009, 92s1: 122-132.

[5] Chaim R Densification Mechanisms in Spark Plasma Sintering of Nanocrystalline Ceramics[J]. Mater. Sci. Eng. A, 2007, 443(1–2): 25-32.

[6] Zhan G D, Kuntz J, Wan J, . Alumina Based Nano Composites Consolidated by Spark Plasma Sintering[J]. Scripta. Mater., 2002, 47: 737-741.

[7] Shen Z J, Johnsson M, Zhao Z, . Spark Plasma Sintering of Alumina[J]. J. Am. Ceram. Soc., 2002, 85: 1 921-1 927.

[8] Zhou Y, Hirao K, Yamauchi Y, . Densification and Grain Growth in Pulse Electric Current Sintering of Alumina[J]. J. Eur. Ceram. Soc., 2004, 24: 3 465-3 470.

[9] Murayama N, Shin W Effect of Rapid Heating on Densification and Grain Growth in Hot Pressed Alumina[J]. J. Ceram. Soc. Japan, 2000, 108: 799-802.

[10] Kim B N, Hiraga K, Morita K, . Effects of Heating Rate on Microstructure and Transparency of Spark-plasma-sintered Alumina[J]. J. Eur. Ceram. Soc., 2009, 29: 323-327.

[11] Meng F C, Fu Z Y, Zhang J Y, . Rapid Densification of Nanograined Alumina by High Temperature and Pressure with a Very High Heating Rate[J]. J. Am. Ceram. Soc., 2007, 90(4): 1 262-1 264.

[12] Zhang J Y, Meng F C The Nature of Grain Boundaries in Alumina Fabricated by Fast Sintering[J]. Scripta. Mater., 2010, 62: 658-661.

[13] Xu C J, Zhang Z X, Zhang J Y A New Route to Fabricate Barium Titanate with High Permittivity [J]. Ceram. Int., 2014, 40: 10 927-10 931.