Mikronaltı Boyutlu Başlangıç Tozuyla Üretilen Y2O3 Katkılı Si3N4 Seramiklerde Sinterleme Proses Çevriminin Termal İletkenliğe Etkisi

Elektronik cihazlarda ısı artışını kontrol ihtiyacı, yüksek termal iletkenlikli altlık malzemelerin üretilmesinin temel nedenini oluşturmaktadır. Si3N4 seramiklerde termal iletkenliği etkileyen parametrelerinin kontrolü ile bu endüstriyel uygulamalar için uygun özellikte malzemeler geliştirilebilir. Sinterleme sonrası mikroyapıda oluşan fazların türü miktarı ve dağılımı termal iletkenliği etkiler. Si3N4 seramiklerin termal iletkenliğine etki eden, bu mikroyapı özellikleri, sinterleme ilavelerine ve sinterleme tekniklerine bağlı olarak değişir. Bu çalışmada, Si3N4 başlangıç tozuna (<1 µm, %2 β), Y2O3 ilave edilerek gaz basınçlı sinterleme (GPS) ile üretilmiş Si3N4 seramiklerin, sinterleme sonrası farklı soğutma çevrimlerinin, mikroyapı ve termal iletkenliğe etkisi araştırılmıştır. Termal iletkenlik, yavaş soğutma ile 42,69 W/m.K, hızlı soğutma ile 44,18 W/m.K elde edilmiştir. Yavaş soğutma ile yoğunluk azalmış, açık porozite artmış, termal iletkenlik ~% 3,5 oranında azalmıştır.

Anahtar Kelimeler:

Termal iletkenlik, GPS, Karakterizasyon

The Effect of Sintering Process Cycle on Thermal Conductivity in Y2O3 Additive Si3N4 Ceramics Produced with Submicron Size Starting Powder

The need for control of temperature rise in electronic devices is a fundamental cause of the production of high thermal conductivity substrate materials. By controlling the parameters affecting thermal conductivity Si3N4 ceramics, materials with suitable properties for the industrial applications can be developed. The amount and distribution of the phases formed in the microstructure after sintering affect the thermal conductivity. These microstructure properties, which affect the thermal conductivity of Si3N4 ceramics, vary depending on sintering additions and sintering techniques. In this study, the effect on microstructure and thermal conductivity of different cooling rates of Si3N4 ceramics gas pressure sintered with Y2O3 addition to Si3N4 starting powder (<1 µm, %2 β) was investigated. Thermal conductivity was 42.69 W/m.K with slow cooling and 44.18 W/m.K with fast cooling. With not fast cooling, density decreased, open porosity increased, thermal conductivity decreased by ~ 3.5% ratio.

Keywords:

Thermal conductivity, GPS, Characterization,

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Cengel Y., “Heat Transfer: A Practical Approach”, J. Chem. Inf. Model., 2013.
Callister W.D., Rethwisch D.G., Fundamental of Material Science and Engineering-An Integrated Approach, 2012.
Srivastava G.P., “Theory of Thermal Conduction in Nonmetals”, Mrs. Bull. 2001, 26 (6), 445-450.
Watari K, Shinde SL, “High Thermal Conductivity Materials”, Mrs. Bull. 2001, 440-441.
Callister W.D., “Materials science and engineering: An introduction (2nd edition)”, Mater. Des., 1991.
Hirao K, Watari K, Hayashi H, Kitayama M., “High Thermal Conductivity Silicon Nitride Ceramic”, Mrs. Bull., 2001.
Haggerty J.S, Lightfoot A., “Opportunities for Enhancing the Thermal Conductivities of SiC and Si3N4 Ceramics Through Improved Processing”, 2008, 475-487.
Watari K, Hirao K, Brito M.E., Toriyama M, Kanzaki S. “Hot İsostatic Pressing to İncrease Thermal Conductivity of Si3N4 Ceramics”. J Mater Res. 1999, 79, 2485-2488.
Okamoto Y, Hirosaki N, Ando M, Munakata F, Akimune Y. “Effect of Sintering Additive Composition on The Thermal Conductivity of Silicon Nitride”, J. Mater. Res., 1998.
Hirao K, Zhou Y, Miyazaki H, Hyuga H. “Improvement in Thermal Conductivity of Silicon Nitride Ceramics via Microstructural Control and Their Application to Heat Dissipation Substrates”, Funtai Oyobi Fummatsu Yakin/Journal Japan Soc. Powder Powder Metall., 2017, 64 (8), 439-444.
K. Hirao, Y. Zhou, H. Hyuga, T. Ohji, ve D. Kusano, “High Thermal Conductivity Silicon Nitride Ceramics”, Journal of the Korean Ceramic Society, 2012, 380-384.
Hampshire S., Jack K.H., “Kınetıcs of Densıfıcatıon and Phase Transformatıon of Nıtrogen Ceramıcs.”, Proceedings of the British Ceramic Society, 1981, 37-49.
Sorrell C.C., McCartney E.R., “Engineering Nitrogen Ceramics: Silicon Nitride, Beta Prime-SiAlON and Cubic Boron Nitride..”, Mater. Forum, 1986, 148-161
Kitayama M, Hirao K, Tsuge A, Watari K, Toriyama M, Kanzaki S., “Thermal Conductivity of β-Si3N4: II, Effect of Lattice Oxygen”, J. Am. Ceram. Soc., 2004.
Zhu X, Zhou Y, Hirao K, Ishigaki T, Sakka Y. “Potential Use of Only Yb2O3 in Producing Dense Si3N4 Ceramics with High Thermal Conductivity by Gas Pressure Sintering”, Sci Technol Adv. Mater., 2010, 11.
Hirosaki N, Okamoto Y, Ando M, Munakata F, Akimune Y., “Thermal Conductivity of Gas-Pressure-Sintered Silicon Nitride”, J. Am. Ceram. Soc., 1996, 79, 2978-2982
Pullum O.J., Lewis M.H., “The Effect of Process Atmosphere on the Intergranular Phase in Silicon Nitride Ceramics”, J. Eur. Ceram. Soc., 1996, 16, 1271-1275.
Kim J.M., Ko S Il., Kim H.N “Effects of Microstructure and Intergranular Glassy Phases on Thermal Conductivity of Silicon Nitride”, Ceram Int. 2017, 43, 5441-5449.
Furuya K, Munakata F, Matsuo K, Akimune Y, Ye J, Okada A, “Microstructural Control of β-Silicon Nitride Ceramics to Improve Thermal Conductivity”, J. Therm. Anal. Calorim., 2002.
Kitayama M, Hirao K, Toriyama M, Kanzaki S “Thermal Conductivity of β-Si3N4 : I, Effects of Various Microstructural Factors”, J Am Ceram Soc. 1999, 82, 3105-3112.
Kitayama M, Hirao K, Toriyama M, Kanzaki S. “Thermal Conductivity of ß-Si3N4: I, Effects of Various Microstructural Factors”, J Am Ceram Soc., 2004.
Uyan P, Turan S., “Effect of Cooling Cycle after Sintering on the Thermal Diffusivity of Y2O3 Doped Si3N4 Ceramics”, Univers. J. Mater. Sci., 2018, 6(1), 39-47.
Gazzara C.P., Messier D.R., “Deterımınatıon of Phase Content of Si3N4 by X-Ray Dıffractıon Analysıs”, Am. Ceram. Soc. Bull., 1977.
Richerson D.W., Modern Ceramic Engineering, Marcel Dekker Inc, NewYork, 2005.
Parker W.J., Jenkins R.J., Butler C.P., Abbott G.L.., “Flash Method of Determining Thermal Diffusivity, Heat Capacity, and Thermal Conductivity”, J. Appl. Phys., 1961, 32, 1679-1684.
Watari K, Seki Y, Ishizaki K “Temperature Dependence of thermal Coefficients for HIPped Silicon Nitride”, Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal Ceram. Soc. Japan. 1989, 97(2), 174-181.
Lin Y, Ning X.S., Zhou H, Chen K, Peng R, Xu W., “Study on the Thermal Conductivity of Silicon Nitride Ceramics with Magnesia and Yttria as Sintering Additives”, Mater Lett. 2002, 57, 15-19.
Bruls R.J., Hintzen HT, Metselaar R. “A new Estimation Method for the Intrinsic Thermal Conductivity of Nonmetallic Compounds”, J. Eur. Ceram. Soc., 2005.
Yokota H, Abe H, Ibukiyama M. “Effect of lattice defects on the thermal conductivity of β-Si3N4”, J. Eur. Ceram. Soc., 2003.
Kingery W.D., Bowen H.K., Uhlmann D.R., Introduction to Ceramics (2nd edition). 1976.
Goldstein J, Newbury D., Joy D., “Scanning Electron Microscopy and X-ray Microanalysis - Third Edition”, Springer, 2003.
Mandal H., “New developments in α -SiAlON Ceramics”, J. Eur. Ceram. Soc., 1999.
Ching W-Y. “‘Electronic Structure and Bonding of All Crystalline Phases in the Silica-Yttria-Silicon Nitride Phase Equilibrium Diagram’”, J. Am. Ceram. Soc., 2005.
Carter C.B., Williams D.B., Transmission Electron Microscopy: Diffraction, Imaging, and Spectrometry, 2016.