Effect of Sintering Process on Structure and Properties of Microcrystalline Ceramic Corundum Abrasive with Nano-Seed

Abstract

Abstract: Al₂O₃ corundum precursor was synthesized by sol-gel technology, and microcrystalline ceramic corundum (SG) abrasive was prepared by traditional sintering technology with SiO₂-MgO-CaO as sintering aids and α-Al₂O₃ nano-powder as crystal seed. The characteristics of seed and thermal properties of gel precursor were analyzed by means of transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermogravimetric-calorimetric scanning (TG-DSC). The effects of sintering temperature and holding time on microstructure and mechanical properties of SG abrasive were studied. The results show that α-Al₂O₃ nano-seed makes the transition temperature of θ-Al₂O₃→α-Al₂O₃ decrease by 250 ℃. With increasing sintering temperature and holding time, the single particle compressive strength and density increase first and then decrease, and the grain morphology changes from equiaxed crystal to platelike crystal. Sintering at 1 320 ℃ for 45 min, the single particle compressive strength and density of SG abrasives reach 40.2 N and 3.88 g/cm³, respectively, and the average particle size is 0.56 μm, which is superior to micron seed abrasive samples prepared by traditional sintering technology.

Key words: sol-gel, microcrystalline ceramic, Al₂O₃ corundum abrasive, single particle compressive strength, sintering aid, crystal seed

CLC Number:

TG316

References

[1] NADOLNY K. State of the art in production, properties and applications of the microcrystalline sintered corundum abrasive grains[J]. The International Journal of Advanced Manufacturing Technology, 2014, 74(9): 1445-1457.
[2] 徐三魁, 赵建昌, 邹文俊. 超微晶刚玉磨料的生产技术及应用[J]. 金刚石与磨料磨具工程, 2007, 27(2): 69-72.
XU S K, ZHAO J C, ZOU W J. Preparation and application of ultrafine corundum abrasive grains[J]. Diamond & Abrasives Engineering, 2007, 27(2): 69-72 (in Chinese).
[3] LI Z C, ZHANG A J, LI Z H, et al. A novel low temperature synthesis technique of sol-gel derived nanocrystalline alumina abrasive[J]. Journal of Sol-Gel Science and Technology, 2011, 57(1): 24-30.
[4] 边华英, 王学涛, 尹青亚, 等. 微晶氧化铝基烧结磨料的制备研究[J]. 河南科学, 2018, 36(7): 1070-1074.
BIAN H Y, WANG X T, YIN Q Y, et al. Preparation of sintered microcrystalline ceramic alumina abrasive[J]. Henan Science, 2018, 36(7): 1070-1074 (in Chinese).
[5] DOAN C P, HAWK J A. Influence of whisker toughening and microstructure on the wear behavior of Si₃N₄- and Al₂O₃-matrix composites reinforced with SiC[J]. Journal of Materials Science, 2000, 35(23): 5793-5807.
[6] 边华英, 陈虎, 王焱, 等. 焙烧温度对微晶陶瓷磨料晶粒度的影响[J]. 中国陶瓷, 2020, 56(11): 33-38.
BIAN H Y, CHEN H, WANG Y, et al. Influence of calcination temperature on grain size of microcrystalline alumina abrasive[J]. China Ceramics, 2020, 56(11): 33-38 (in Chinese).
[7] LI Z C, LI Z H, ZHANG A J, et al. Synthesis and two-step sintering behavior of sol-gel derived nanocrystalline corundum abrasives[J]. Journal of the European Ceramic Society, 2009, 29: 1337-1345.
[8] LI X L, LI Z H, ZHU Y M. Effect of CoO-NiO additives on the microstructure and mechanical properties of microcrystalline corundum abrasives with in-situ formed needle-shaped LaAl₁₁O₁₈[J]. Ceramics International, 2022, 48: 33794-33800.
[9] 张云浩, 李志宏, 朱玉梅. 烧结添加剂和晶种对新型陶瓷刚玉磨料烧结的影响[J]. 金刚石与磨料磨具工程, 2006, 26(5): 74-76.
ZHANG Y H, LI Z H, ZHU Y M. Effect of additives and crystal seed on sintering of new ceramics corundum abrasives[J]. Diamond & Abrasives Engineering, 2006, 26(5): 74-76 (in Chinese).
[10] HAN Y, LI Z H, ZHU Y M. Effect of MgO-TiO₂-SiO₂ additions on in situ anisotropic grains growth and mechanical properties of corundum abrasive using pseudo-boehmite as raw material[J]. Ceramics International, 2020, 46(2): 1934-1939.
[11] OBERBACH T, GÜNTHER C, WERNER G, et al. Influence of different amounts of hematite seedings on the temperature of phase transformation of transition aluminas into corundum[J]. Thermochimica Acta, 1996, 271: 155-162.
[12] LI Z C, LI Z H, ZHANG A J, et al. Synergistic effect of α-Al₂O₃and (NH₄)₃AlF₆ co-doped seed on phase transformation, microstructure, and mechanical properties of nanocrystalline alumina abrasive[J]. Journal of Alloys and Compounds, 2009, 476: 276-281.
[13] YOU J L, YANG T, FENG D D, et al. Synthesis and two-step sintering behavior of solution derived corundum abrasives with plate-like grains[J]. Ceramics International, 2018, 44(11): 12615-12620.
[14] 易中周, 肖冰, 杨为佑, 等. 晶种对氢氧化铝转相和热压烧结氧化铝晶形变化的影响[J]. 无机材料学报, 2004, 19(6): 1287-1292.
YI Z Z, XIAO B, YANG W Y, et al. Influence of α-alumina seeds on transformation of aluminium hydroxide and morphology of alumina grain in hot-pressing[J]. Journal of Inorganic Materials, 2004, 19(6): 1287-1292 (in Chinese).
[15] NOFZ M, STÜSSER R, SCHOLZ G, et al. The thermally induced transformation of pseudoboehmite gels-a comparison of the effects of corundum seeding and iron doping[J]. Journal of the European Ceramic Society, 2005, 25(7): 1095-1107.
[16] KAPŁONEK W, NADOLNY K, HABRAT W. Morphology of near- and semispherical melted chips after the grinding processes using sol-gel abrasives based on SEM-imaging and analysis[J]. Advances in Materials Science and Engineering, 2016, 2573920: 1-12.
[17] KAO H C, WEI W C. Kinetics and microstructural evolution of heterogeneous transformation of θ-alumina to α-alumina[J]. Journal of the American Ceramic Society, 2004, 83(2): 362-368.
[18] 李国星, 卢红霞, 孙洪巍, 等. MgB₂等镁化物添加剂对氧化铝陶瓷晶粒生长形貌的影响[J]. 中国陶瓷工业, 2005, 12(1): 12-14+11.
LI G X, LU H X, SUN H W, et al. The effect of MgB₂ and other magnesia-based additives on the growth and microstructure of alumina grains[J]. China Ceramic Industry, 2005, 12 (1): 12-14+11 (in Chinese).
[19] 黄晓巍. Al₂O₃/3Y-TZP复相陶瓷的液相烧结机理[J]. 福州大学学报(自然科学版), 2005, 33(5): 624-627.
HUANG X W. Mechanism of liquid phase sintering for Al₂O₃/3Y-TZP composite[J]. Journal of Fuzhou University(Natural Sciences Edtion), 2005, 33(5): 624-627 (in Chinese).
[20] LI N, ZHU Y M, GAO K, et al. Preparation of sol-gel derived microcrystalline corundum abrasives with hexagonal platelets[J]. International Journal of Minerals, Metallurgy and Materials, 2013, 20(1): 71-75.
[21] 李海涛, 王广欣, 彭坤, 等. 锌硼共掺对铌酸钾钠基压电陶瓷结构和性能影响的研究[J]. 功能材料, 2019, 50(2): 2006-2011.
LI H T, WANG G X, PENG K, et al. Study of structures and properties of NKN-based piezoelectric ceramics co-doped with ZnO and B₂O₃[J]. Journal of Functional Material, 2019, 50(2): 2006-2011 (in Chinese).
[22] LI N, ZHU Y M, GAO K, et al. Preparation of sol-gel derived microcrystalline corundum abrasives with hexagonal platelets[J]. International Journal of Minerals, Metallurgy, and Materials, 2013, 20(1): 71-75.