摘要
以Al_(4)SiC_(4)为原料、Y2O3为添加剂,采用无压烧结制备Y_(3)Al_(5)O_(12)–Al4Si C4复合耐火材料,研究Y2O3添加量[0~5%(质量分数)]对复合材料物相组成、微观形貌与力学性能的影响,并通过DFT模拟计算Y^(3+)对Al_(4)Si C_(4)不同晶面表面能的影响。结果表明:高温下Y_(2)O_(3)与Al_(4)SiC_(4)表面固有氧化层形成共晶液相,在复合材料晶界处生成Y_(3)Al_(5)O_(12)和少量Y2SiO5。Y2O3的添加促使Al_(4)Si C_(4)晶粒沿二维平面生长,由不规则状向六方片状转变,这是由于添加剂中Y^(3+)降低了晶面的表面能。复合材料的抗折强度随Y2O3添加量增加呈现先增大后降低趋势,当Y2O3添加量为3%时,尺寸均一的六方片状Al_(4)Si C_(4)晶粒交错生长构筑成骨架结构,Y_(3)Al_(5)O_(12)弥散分布于Al_(4)SiC_(4)晶界处,Y_(3)Al_(5)O_(12)–Al4Si C4复合材料力学性能得到提升,复合材料体积密度、显气孔率和抗折强度分别为2.44 g·cm^(–3)、20.15%和52.7 MPa。
Y_(3)Al_(5)O_(12)-Al_(4)SiC_(4) composite refractory was prepared via pressureless sintering with Al_(4)SiC_(4) as a raw material and Y2O3 as an additive.The effect of Y2O3 addition(i.e.,0-5%in mass fraction)on the phase composition,microstructure and mechanical properties of the composite was investigated,and the ffect of ya+ions on the surface energy of Algsic4 different crystal faces was calculated via the DFT simulation.The results show that the addition of Y_(2)O_(3) can form an eutectic liquid phase with anintrinsic oxide layer on the surface of Al_(4)SiC_(4) at a high temperature,Y_(3)Al_(5)O_(12) and a small amount of Y2SiOs appear at the grain boundary of the composite.The addition of Y_(2)O_(3) promotes the growth of Al4SiC4 grains along the two-dimensional plane and the transformation from irregular to hexagonal flakes due to the reduction of surface energy of different crystal faces of Al_(4)SiC_(4) by y3+in the additive,according to the DFT results.The flexural strength of the composite first increases and then decreases with the increase of Y2O3 addition.At theY2O3 addition of 3%,the hexagonal lamellar Al_(4)SiC_(4) grains with a uniform size form a staggered skeleton structure,and Y_(3)Al_(5)O_(12) dispersesat the grain boundary of Al_(4)SiC_(4),which is conducive to the improvement of the mechanical properties of Y_(3)Al_(5)O_(12)-Al_(4)SiC_(4) composite.The bulk density,apparent porosity and flexural strength of the composite are 2.44 g·cm^(-3),20.15%and 52.7MPa,respectively.
作者
邓孝兵
邓承继
邢广超
丁军
王周福
马北越
祝洪喜
余超
DENG Xiaobing;DENG Chengji;XING Guangchao;DING Jun;WANG Zhoufu;MA Beiyue;ZHU Hongxi;YU Chao(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;School of Metallurgy,Northeastern University,Shenyang 110819,China)
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2023年第6期1555-1564,共10页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(U21A2057)
湖北省重点研发计划项目(2022BAA032)。
关键词
碳硅化铝
钇铝石榴石
复合材料
耐火材料
力学性能
aluminium silicon carbide
yttrium aluminium garnet
composite
refectory
mechanical properties
作者简介
第一作者:邓孝兵(1997-),男,硕士研究生;通信作者:余超(1986-),男,博士,副教授。
