焦宝石基结构梯度耐火材料的设计及热应力分析
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摘要
为了改善耐火材料的抗热震性能,从梯度耐火材料的性能梯度和结构梯度出发,以焦宝石、α-Al_2O_3微粉和SiO_2微粉为原料,磷酸二氢铝溶液为结合剂,混练后的泥料分别在20、60、100和140 MPa的压力下成型,再于600℃保温3 h热处理制成焦宝石基黏土砖,然后检测不同成型压力试样的热膨胀性、显气孔率、热导率和弹性模量,并利用ANSYS有限元法对不同成型压力试样的性能渐变梯度(自身温度场原位形成)和结构梯度(气孔结构)进行叠加,在热面温度和冷面温度分别为1 300和500℃的边界条件下,对叠加前后的结构进行温度、应力、变形量的模拟分析研究。结果表明:1)试样的热膨胀系数随温度升高而逐渐降低,在设定边界条件下的温度场作用下,可以形成较适宜的性能渐变梯度;不同结构试样的热膨胀曲线有一定差异,可用于结构梯度耐火材料的设计。2)在性能渐变梯度与结构梯度叠加作用下,结构梯度D1(从高温面到低温面成型压力增加)与结构梯度D2(从高温面到低温面成型压力降低)相比,结构梯度D1的最大应力较小,沿Y轴负方向的最大变形量显著降低;与均一结构相比,结构梯度D2的最大应力与最大变形量显著增加,结构梯度D1的最大应力与成型压力为60、100、140 MPa的均一结构相比明显改善。3)成型压力对试样结构的改变有限,需要对其性能梯度和结构梯度进行进一步优化,使试样热膨胀曲线与理想曲线接近或一致。
This work aims at improving the thermal shock resistance of refractories from the aspect of gradient refractories with property gradient and structural gradient. Flint clay,α-Al2 O3 micropowder,and Si O2 micropowder were used as starting materials,and aluminium dihydrogen phosphate solution as the binder to prepare flint clay based brick. The materials were shaped( 20,60,100 and 140 MPa),and fired at 600 ℃ for3 h to obtain the specimens. The thermal expansibility,apparent porosity,thermal conductivity and elastic modulus of the specimens were measured. The property gradient( in situ formation by the self temperature field) and structural gradient( pore structure) of the specimens shaped under different pressures were superimposed using ANSYS finite element method. Numerical simulation analysis on the temperature field,stress field and structure deformation before and after the superimposition was carried out with the boundary conditions: the hot surface temperature of 1 300 ℃ and the cold surface temperature of 500 ℃. The results show that: 1) the thermal expansion coefficient of the specimens decreases gradually with the increase of the temperature; and with the boundary condition of the temperature field,suitable property gradient can be formed. The thermal expansion curves of specimens with different structures are different,which can be used for the design of structural gradient refractories. 2) Under the superimposition of property gradient and structural gradient,structural gradient D1( molding pressure increasing from high temperature face to low temperature face) has smaller maximum stress than D2( molding pressure decreasing from high temperature face to low temperature face); and the maximum deformation along the negative direction of Y axis decreases significantly. Compared with the uniform structure,structural gradient D2 has significantly larger maximum stress and deformation. Compared to the uniform structure with molding pressure of 60 MPa,100 MPa and 140 MPa,D1 of gradient structure has significantly decreased maximum thermal stress; 3) the molding pressure has limited effect on the specimen structure,so the property gradient and structural gradient should be further optimized to make the thermal expansion curve of the specimen close to or coincide with the ideal curve.
This work aims at improving the thermal shock resistance of refractories from the aspect of gradient refractories with property gradient and structural gradient. Flint clay,α-Al2 O3 micropowder,and Si O2 micropowder were used as starting materials,and aluminium dihydrogen phosphate solution as the binder to prepare flint clay based brick. The materials were shaped( 20,60,100 and 140 MPa),and fired at 600 ℃ for3 h to obtain the specimens. The thermal expansibility,apparent porosity,thermal conductivity and elastic modulus of the specimens were measured. The property gradient( in situ formation by the self temperature field) and structural gradient( pore structure) of the specimens shaped under different pressures were superimposed using ANSYS finite element method. Numerical simulation analysis on the temperature field,stress field and structure deformation before and after the superimposition was carried out with the boundary conditions: the hot surface temperature of 1 300 ℃ and the cold surface temperature of 500 ℃. The results show that: 1) the thermal expansion coefficient of the specimens decreases gradually with the increase of the temperature; and with the boundary condition of the temperature field,suitable property gradient can be formed. The thermal expansion curves of specimens with different structures are different,which can be used for the design of structural gradient refractories. 2) Under the superimposition of property gradient and structural gradient,structural gradient D1( molding pressure increasing from high temperature face to low temperature face) has smaller maximum stress than D2( molding pressure decreasing from high temperature face to low temperature face); and the maximum deformation along the negative direction of Y axis decreases significantly. Compared with the uniform structure,structural gradient D2 has significantly larger maximum stress and deformation. Compared to the uniform structure with molding pressure of 60 MPa,100 MPa and 140 MPa,D1 of gradient structure has significantly decreased maximum thermal stress; 3) the molding pressure has limited effect on the specimen structure,so the property gradient and structural gradient should be further optimized to make the thermal expansion curve of the specimen close to or coincide with the ideal curve.
引文
[1]李楠,顾华志,赵惠忠.耐火材料学[M].北京:冶金工业出版社,2010:4-5.
[2]周馨我.功能材料学[M].北京:北京理工大学出版社,2002:290-307.
[3]王永寿.倾斜功能材料展望[J].飞航导弹,1991(8):58-60.
[4]冯改山.性能渐变材料原理及其应用于耐火材料的技术可能性[J].耐火材料,1994,28(8):300-303.
[5]韩杰才,徐丽,王保林,等.功能梯度材料的研究进展及展望[J].固体火箭技术,2004,27(3):207-215.
[6]曹喜营,柳军,冯海霞. TRIZ创新方法解决耐火材料热剥落问题[J].河南科技,2015(4):147-151.
[7]田锋,于建宾,刘国齐,等.高可靠性梯度功能耐火材料[J].耐火材料,2014,48(6):455-457.
[8]丁保华,李文超.梯度功能材料的研究现状与展望[J].耐火材料,1998,32(5):295-298.
[9]邹俭鹏,阮建明,周忠诚,等.功能梯度材料的设计与制备以及性能评价[J].粉末冶金材料科学与工程,2005,10(2):78-87.
[10]杨健,张玲,纪嘉宁,等.合成CaTiO3粉加入量对烧结镁砖性能的影响[J].耐火材料,2017,51(2):136-139.
[11]董萌蕾,徐恩霞,王玉霞.硅粉加入量对Si3N4结合刚玉材料性能的影响[J].耐火材料,2017,51(1):37-40.
[12]杨文刚,杨凤玲,李红霞,等.沥青种类和硝酸镍对铝碳材料性能与结构的影响[J].耐火材料,2016,50(6):325-328.
[13]郑卫,杨金松,李红霞,等.添加剂对尖晶石碳质材料性能的影响[J].耐火材料,2016,50(5):348-351.
[14]王月月,鄢文,李楠,等.蓝晶石含量对轻质莫来石-刚玉浇注料显微结构与性能的影响[J].耐火材料,2017,51(4):246-249.
[15]李鹏涛,孙红刚,李坚强,等.电熔锆莫来石对Al2O3-Cr2O3耐火材料抗热震性能的影响[J].耐火材料,2017,51(4):250-254.
[16]宋信钊,叶方保,石凯,等.蓝晶石基莫来石对水泥窑用硅莫砖性能的影响[J].耐火材料,2017,51(4):289-292.
[17]丁达飞,李志坚,陈俊红,等.超声波脉冲速度法研究镁铁铝材料的抗热震性[J].耐火材料,2015,49(5):349-351.
[18]刘辉敏.基于有限单元法评价长水口的抗热震性能[J].耐火材料,2015,49(3):186-189.
[19]姚佳.耐火材料热震性能与微应力场重构[D].郑州:郑州大学,2014.
[20]袁广亮,薛群虎,李翔,等. Al2O3-Zr O2复合粉对Zr O2质定径水口抗热震性的影响[J].耐火材料,2014,48(2):81-83.
[2]周馨我.功能材料学[M].北京:北京理工大学出版社,2002:290-307.
[3]王永寿.倾斜功能材料展望[J].飞航导弹,1991(8):58-60.
[4]冯改山.性能渐变材料原理及其应用于耐火材料的技术可能性[J].耐火材料,1994,28(8):300-303.
[5]韩杰才,徐丽,王保林,等.功能梯度材料的研究进展及展望[J].固体火箭技术,2004,27(3):207-215.
[6]曹喜营,柳军,冯海霞. TRIZ创新方法解决耐火材料热剥落问题[J].河南科技,2015(4):147-151.
[7]田锋,于建宾,刘国齐,等.高可靠性梯度功能耐火材料[J].耐火材料,2014,48(6):455-457.
[8]丁保华,李文超.梯度功能材料的研究现状与展望[J].耐火材料,1998,32(5):295-298.
[9]邹俭鹏,阮建明,周忠诚,等.功能梯度材料的设计与制备以及性能评价[J].粉末冶金材料科学与工程,2005,10(2):78-87.
[10]杨健,张玲,纪嘉宁,等.合成CaTiO3粉加入量对烧结镁砖性能的影响[J].耐火材料,2017,51(2):136-139.
[11]董萌蕾,徐恩霞,王玉霞.硅粉加入量对Si3N4结合刚玉材料性能的影响[J].耐火材料,2017,51(1):37-40.
[12]杨文刚,杨凤玲,李红霞,等.沥青种类和硝酸镍对铝碳材料性能与结构的影响[J].耐火材料,2016,50(6):325-328.
[13]郑卫,杨金松,李红霞,等.添加剂对尖晶石碳质材料性能的影响[J].耐火材料,2016,50(5):348-351.
[14]王月月,鄢文,李楠,等.蓝晶石含量对轻质莫来石-刚玉浇注料显微结构与性能的影响[J].耐火材料,2017,51(4):246-249.
[15]李鹏涛,孙红刚,李坚强,等.电熔锆莫来石对Al2O3-Cr2O3耐火材料抗热震性能的影响[J].耐火材料,2017,51(4):250-254.
[16]宋信钊,叶方保,石凯,等.蓝晶石基莫来石对水泥窑用硅莫砖性能的影响[J].耐火材料,2017,51(4):289-292.
[17]丁达飞,李志坚,陈俊红,等.超声波脉冲速度法研究镁铁铝材料的抗热震性[J].耐火材料,2015,49(5):349-351.
[18]刘辉敏.基于有限单元法评价长水口的抗热震性能[J].耐火材料,2015,49(3):186-189.
[19]姚佳.耐火材料热震性能与微应力场重构[D].郑州:郑州大学,2014.
[20]袁广亮,薛群虎,李翔,等. Al2O3-Zr O2复合粉对Zr O2质定径水口抗热震性的影响[J].耐火材料,2014,48(2):81-83.