مقایسه اثر افزودنی های نانو و مزوپور آلومینا با نانو کامپوزیت های آنها به همراه نانو لوله های کربن بر ریز ساختار، خواص فیزیکی و مکانیکی دیرگدازهای آلومینا – کربن
محورهای موضوعی : سرامیک ها و مواد نسوز
1 - no.112,negin abshar building,rezvan alley ,abshar
کلید واژه: نانو لوله کربنی, آلومینا-کربن, مزوپور آلومینا, دیرگدازها,
چکیده مقاله :
دیرگدازهای پایه آلومینا-کربن به دلیل خواص فیزیکی و مکانیکی منحصربه فرد خود به طور گسترده به عنوان دریچه کشویی و شرود نازل... در صنعت مورد استفاده قرارمی گیرد. در این تحقیق تاثیر افزودنی های آلومینا‌ی (نانو و مزوپور) و کامپوزیت آنها به همراه نانو لوله کربنی دردیرگدازهای آلومینا –کربن مورد بررسی قرار گرفت.در این راستا،مزوپورآلومینا با روش سل-ژل سنتز شد.سپس مزوپور آلومینا و نانو آلومینا به نانو لوله کربنی عاملدار جهت تهیه نانو کامپوزیت اضافه گردید.جهت توزیع نانو افزودنی ها،مقادیر1.5-0.5 Wt% به جزءریزدانه اضافه شد و پس از آن با ذرات درشت موجود در بدنه آلومینا-کربن مخلوط گردید. در ادامه جهت بررسی خواص فیزیکی و مکانیکی نمونه ها تحت پرس با فشارMPa150 شکل دهی و تحت بستر کک در دمای ℃200 با ماندگار 6hr تمپر و در دمای℃ 1450 به مدت 2hr در محیط احیایی تحت کک پخت داده شدند. چگالی ظاهری(DIN 993-1)، تخلخل ظاهری(DIN 993-1) و استحکام فشاری سرد(993-5 DIN 993-7) بر اساس استانداردها تعیین گردید و جهت تحلیل ریز ساختار و آنالیز فازی از SEM و XRD استفاده شد. نتایج نشان داد که نمونه حاوی 1Wt% کامپوزیت نانو آلومینا-نانو لوله کربنی چند دیواره دارای بالاترین استحکام فشاری سرد در حدودMPa 137 و نمونه با 1.5Wt% مزوپور آلومینا کمترین استحکام فشاری سرد در حدودMPa 94 را دارد. بهبود خواص مکانیکی می تواند با تشکیل بیشتر SiC درحضور Al2O3- MWCNT توسط مکانیزم بخار-جامد مرتبط باشد.دلیل اصلی کاهش خواص مکانیکی با استفاده از افزودنی های مزوپور می‌تواند به محدودیت واکنش گاز-جامد کمتر تشکیل شدن SiC در فاز زمینه ارتباط داده شود.
Alumina-C refractories have been widely used as slide gate submerged entry nozzles and mono block stoppers in steelmaking due to their unique physical and mechanical properties.In this research,the effect of different source of alumina having unlike surface areas(nano and mesoporous)and MWCNT additives on physical and mechanical properties of Al2O3-C refractories was investigated.In this regard mesoporous alumina was synthesized by sol-gel method.Then the mesoporous and nano alumina precursors were added to the functionalized MWCNT.In order to better distribution of 0.5-1.5 wt% nano additives the additives were firstly added to the matrix and then mixed with coarse particles of Al2O3-C refractories. Following in order to physical and mechanical properties investigation, all samples pressed under 150Mpa pressure by uniaxial then pressed and tempered at 200 ℃ for 6h, and afterward fired under coke atmosphere at 1450℃ for 2 h.The bulk density apparent porosity and cold crushing strength were determined according to their respective standard. Moreover their microstructure and phase analysis was investigated by XRD and SEM.The results confirmed that the sample containing1wt% nano Al2O3-MWCNT composite showed the highest CCS of about 137 Mpa,and sample with1.5 wt% mesoporous Al2O3 showed the lowest CCS (94 Mpa).The improvement of mechanical properties could be related to the higher SiC formation in the presence of nano Al2O3- MWCNT by vapor- solid mechanism. The main reason for decreasing mechanical properties in the presence of mesoporous additives could be attributed to limiting of gas-solid reaction due to trap of gases and therefore lower formation of SiC whiskers through the matrix.
[1]¬ N. Liao, Y. Li, Sh. Jin, Sh. Sang & G. Liu, "Reduced brittleness of multi-walled carbon nanotubes (MWCNT) containing Al2O3-C refractories with boron carbide", Materials science & engineering A, vol. 698, pp. 80-87, 2017.
[2] C. Atzenhofer, S. Gschiel & H. Harmuth, "Phase formation in Al2O3-C refractories with Al addition", Journal of the European Ceramic Society, vol. 37, no, 4, pp. 1805-1810, 2017.
[3] V. Roungos & C. G. Aneziris, "Improved thermal shock performance of Al2O3–C refractories due to nano-scaled additives", Ceramics International, vol. 38, no. 2, pp. 919-927, 2012.
[4] H. B. Fan, Y. W. Li & S. B. Sang, "Microstructures and mechanical properties of Al2O3–C refractories with silicon additive using different carbon sources", Materials Science and Engineering A, vol. 528, no.7-8, pp. 3177-3185, 2011.
[5] H. Shikano, "Refractories Handbook", Technical Association of refractories, 1998.
[6] M. Luo, Y. Li, Sh. Jin, Sh. Sang, L. Zhao & Y. Li, "Microstructures and mechanical properties of Al2O3-C refractories with addition of multi walled carbon nanotubes", Materials science and engineering A, vol. 548, pp. 134-141, 2012.
[7] V. Roungos, C. G. Aneziris & H. Berek, "Novel Al2O3 refractories with less residual carbon due to nanoscaled additives for continuous steel casting application", Advance Engineering materials, vol. 14, no. 4, pp. 255-264, 2012.
[8] V. Roungos & C. G. Aneziris. "Improved thermal shock performance of Al2O3-C refractories due to nanoscaled additives", ceramics international, vol. 38, no. 2, pp.919-927, 2012.
[9] N. Brachhold, J. Fruhstorfer, A. Mertke & C. G. Aneziris. "Carbon bonded alumina refractories with reduced carbon content due to the addition of semi-conductive silicon and/ or nanoparticles", Journal of Ceramic sience and technology, vol. 7, pp. 209-222, 2016.
[10] Z. Huizhong, W. Bin & W. Houzhi, "Influences of nano-alumina and nano-silica on sintering and mechanical property of corundum refractories", Naihuo Cailiao, pp. 472-482, 2002.
[11] C. G. Aneziris, U. Klippel, W. Scharfl, V. Stein & Y. Li, "Functional refractory material design for advanced thermal shock performance due to Titania additions", Applied Ceramic Technology, vol. 4, no. 6, pp. 481-489, 2007.
[12] Z. Ji, N, Liao, Y. Li, M. Nath, T. Zhu & L, Pan, Y. Dai, "Effect of h-BN on the microstructure and fracture behavior of low carbon Al2O3-C refractories", Ceramics International, vol. 47, no. 21, pp.29900-29907, 2021.
[13] A. Baghaei, A. B. Nourbakhsh & R. Ebrahimi Kahrizsangi, "Inclusion removal mechanisms of Al-Killed 304 low carbon stainless steel melt using hercynite coted Al2O3-C ceramic foam filters", Advance Materials and processing, vol. 9, no. 2, pp. 27-37,2021.
[14] S. Badogaa, R. V. Sharmaa, A. K. Dalai & J. Adjaye, "Synthesis and characterization of mesoporous aluminas with different pore sizes: Application in NiMo supported catalyst for hydrotreating of heavy gas oil", Applied Catalysis A: general, vol. 489, pp. 86-97, 2015.
[15] N. Bakhsh, F. A. Khalid & A. S. Hakeem, "Synthesis and characterization of pressureless sintered carbon nanotube reinforced alumina nano composites", Materials science and engineering: A, vol. 578, pp. 422-429, 2013.
[16] L. kumaria, T. Zhang, G. H. Du, W. Z. Li, Q. W. Wang, A. Datyec & K. H. Wu, "Termal of properties CNT-Alumina nanocomposites", composite science and technology, vol. 68, no. 9, pp. 2178-2183, 2008.
[17] A. Kołodziejczak-Radzimska, A. Budna, F. Ciesielczyk, D. Moszyński & T. Jesionowski," Laccase from Trametes versicolor supported onto mesoporous Al2O3: Stability tests and evaluations of catalytic activity", Process Biochemistry, vol. 95, pp. 71-80, 2020.
[18] S. Lu & Y. Liu, "Preparation of meso-macroporous carbon nanotube-alumina composite
monoliths and their application to the preferential oxidation of CO in hydrogen-rich gases", Applied catalysis B: Environmental, vol. 111-112, pp. 492-501, 2012.
[19] A. P. Daluz, M. A. L. Braulio & V. C. Pandolfelli, "Refractory castable engineering", Germany, Göller Verlag, 2015.
[20] S. Badoga, R. Sharma, A. Dalai & J. Adjaye, "Synthesis and characterization of mesoporous alumina with different pore sizes: Application in NiMo supported catalyst for hydrotreating of heavy gas oil", Applied Catalysis A: General, vol. 489, pp. 86-97, 2015.
[21] L. Ahmad, M. Unwin, H. Cao, H.chen, H. Zhao, A. Kennedy & Y. Q. Zhu, "Multi-walled carbon nanotubes reinforced Al2O3 nanocomposites: Mechanical properties and interfacial investigations", composites science and technology, vol. 70, no, 8, pp. 1199-1206, 2010.
[22] H. Barzegar-Bafrooei & T. Ebadzadeh, "Synthesis of nanocomposite powders of alumina carbon nanotube by sol-gel method", advanced powder technology, vol. 22, no. 3, pp. 366-369, 2011.
[23] F. Inam, A. Heaton, P. Brown, T. Peijs & M. Reece, "Effect of dispersion surfactants on the properties of ceramic-carbon nanotube (CNT) nanocomposites", ceramics international, vol. 40, no. 1, pp. 511-516, 2014.
[24] B. Chan, I. Moseung, T. Chakyung, H. Kimkyung, H. Leesoon & H. Hong, "Fabrication of carbon nanotube reinforced alumina matrix nanocomposite by sol–gel process", materials science and engineering A, vol. 395, no. 1-2, pp. 124-128, 2005.
[25] T. Wei, Zh. Fan, G. Luo & F. Wei, "A new structure for multi-walled carbon nanotubes reinforced alumina nanocomposite with high strength and toughness", Materials Letters, vol. 62, no. 4-5, pp. 641-644, 2008.
[26] S. Sarkar & P. Kr. Das, "Processing and properties of carbon nanotube/alumina nanocomposites: a review", advance study center, vol. 37, no. 1, pp. 53-82, 2014.
[27] N. Bakhsh, F. A. Khalid & A. S. Hekeem, "Effect of sintering temperature on densification and mechanical properties of pressureless sintered CNT-alumina nanocomposites", materials science and engineering, vol. 60, no. 1, 2014.
[28] I. Ahmad, M. Unwin, H. Co, H. Chen, H. Zhao, A. Kennedy & Y. Q. Zhu, "Multi-walled carbon nanotubes reinforced Al2O3 nanocomposites: Mechanical properties and interfacial investigations", composite science and technology, vol. 70, no. 8, pp. 1199-1206, 2010.
[29] F. Liang, N. Li & B. Liu & Zh. He, "Processing and characterization of Multi-walled carbon nanotubes containing alumina-carbon refractories prepared by nanocomposite powder technology", Metal and Materials Society and ASM international, vol. 47B, pp. 1661-1668, 2016.
[30] X. Li, G. Zhang, R. Tronstad & O. Ostrovski, "Synthesis of SiC whiskers by VLS and VS process", ceramics international, vol. 42, no. 5, pp. 5668-5676, 2015.
[31] A. W. Weimer, K. J. Nilsen, G. A. Cocheran & R. P. Roach, "Kinetics of carbothermal reduction Synthesis of beta silicon carbide" ceramics and advanced material research, vol. 39, no. 3, pp. 493-503, 1993.