可计及温度与层状结构影响的超高温陶瓷基复合材料涂层残余热应力理论表征模型
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摘要
目的创建可计及温度与层状结构共同影响的超高温陶瓷基复合材料涂层与基体层因热不匹配导致的残余热应力的理论表征模型。方法基于经典的层合板理论与超高温陶瓷基复合材料热物理性能参数对温度的敏感性研究,引入温度和层状结构对涂层与基体层所受残余热应力的影响,形成各层残余热应力温度相关性的理论表征方法,并以ZrB_2-SiC复合材料涂层为例,利用该理论方法系统地研究了各种控制机制对残余热应力的影响及其随温度的演化规律。结果超高温陶瓷基复合材料涂层与基体层所受的残余热应力随着温度的变化而变化,涂层热膨胀系数与基体层热膨胀系数差别越大,变化幅度越大。当涂层材料热膨胀系数大于基体层材料热膨胀系数时,涂层材料遭受残余拉应力,基体层材料遭受残余压应力;随着涂层厚度的增加,涂层所受拉应力减小,而基体层所受压应力增大;当涂层材料热膨胀系数小于基体层材料热膨胀系数时,涂层材料遭受残余压应力,基体层材料遭受残余拉应力;随着涂层厚度的增加,涂层所受压应力减小,而基体层所受拉应力增大。低温下,各层所受残余热应力对层厚与每层材料组成的变化比较敏感,随着温度的升高,敏感性降低。结论对于涂层材料,应设计涂层材料的热膨胀系数小于基体层材料的热膨胀系数,使涂层遭受残余压应力,这不仅能够降低材料表面产生裂纹的危险,同时可以抑制表面已有缺陷的扩展。同时应当设计相对较小的涂层厚度,以增大涂层所受的残余压应力,降低基体层所受的残余拉应力,有效提高整体材料在不同温度下的强度性能。
The work aims to build a theoretical characterization model for residual thermal stresses due to thermal mismatch between the ultra-high temperature ceramic matrix composite coatings under the effects of temperature and laminated structure and the matrix layer. Based on the classical lamination theory and the sensitivities of thermo-physical properties parameters of ultra-high temperature ceramic matrix composites to temperature, the combined effects of temperature and laminated structures were introduced into the residual thermal stress of coating and matrix layer to form the theoretical characterization method for temperature-dependent residual thermal stress. ZrB_2-SiC composite coatings were taken as example to study the effects of varieties of control mechanisms on the residual thermal stresses and the evolutions with temperature in detail by the theoretical method. The residual thermal stresses in the ultra-high temperature ceramic matrix composite coatings and the matrix layer changed with the variation of temperature. The bigger the difference between the thermal expansion coefficients of coating and matrix layer was, the greater the range of variation was. When the thermal expansion coefficient of coatings was bigger than that of the matrix layer, the coatings suffered from the residual tensile stresses, and the matrix layer suffered from the residual compressive stress. With the increase of thickness of coating, the residual tensile stresses in coating decreased, while the residual compressive stress in matrix layer increased. When the thermal expansion coefficient of coatings was smaller than that of the matrix layer, the coatings suffered from the residual compressive stresses, and the matrix layer suffered from the residual tensile stress. With the increase of thickness of coating, the residual compressive stresses in coating decreased, while the residual tensile stress in matrix layer increased. At low temperature, the residual thermal stresses in the coatings and matrix layer were sensitive to temperature, while the sensitivities decreased as the temperature increased. Therefore, the thermal expansion coefficient of the coating should be designed to be smaller than that of the matrix layer, as to make the residual compressive stress in the coating. This can not only reduce the danger of the formation of surface flaw of materials, but also restrain the propagation of the existing surface flaw. Additionally, the relative smaller thickness of the coatings can be designed. This can increase the residual compressive stress in coatings and decrease the residual tensile stress in matrix layer, leading to the effective improvement of strength performance of the monolithic materials under different temperatures.
The work aims to build a theoretical characterization model for residual thermal stresses due to thermal mismatch between the ultra-high temperature ceramic matrix composite coatings under the effects of temperature and laminated structure and the matrix layer. Based on the classical lamination theory and the sensitivities of thermo-physical properties parameters of ultra-high temperature ceramic matrix composites to temperature, the combined effects of temperature and laminated structures were introduced into the residual thermal stress of coating and matrix layer to form the theoretical characterization method for temperature-dependent residual thermal stress. ZrB_2-SiC composite coatings were taken as example to study the effects of varieties of control mechanisms on the residual thermal stresses and the evolutions with temperature in detail by the theoretical method. The residual thermal stresses in the ultra-high temperature ceramic matrix composite coatings and the matrix layer changed with the variation of temperature. The bigger the difference between the thermal expansion coefficients of coating and matrix layer was, the greater the range of variation was. When the thermal expansion coefficient of coatings was bigger than that of the matrix layer, the coatings suffered from the residual tensile stresses, and the matrix layer suffered from the residual compressive stress. With the increase of thickness of coating, the residual tensile stresses in coating decreased, while the residual compressive stress in matrix layer increased. When the thermal expansion coefficient of coatings was smaller than that of the matrix layer, the coatings suffered from the residual compressive stresses, and the matrix layer suffered from the residual tensile stress. With the increase of thickness of coating, the residual compressive stresses in coating decreased, while the residual tensile stress in matrix layer increased. At low temperature, the residual thermal stresses in the coatings and matrix layer were sensitive to temperature, while the sensitivities decreased as the temperature increased. Therefore, the thermal expansion coefficient of the coating should be designed to be smaller than that of the matrix layer, as to make the residual compressive stress in the coating. This can not only reduce the danger of the formation of surface flaw of materials, but also restrain the propagation of the existing surface flaw. Additionally, the relative smaller thickness of the coatings can be designed. This can increase the residual compressive stress in coatings and decrease the residual tensile stress in matrix layer, leading to the effective improvement of strength performance of the monolithic materials under different temperatures.
引文
[1]OPEKA M M,TALMY I G,WUCHINA E J,et al.Mechanical,thermal,and oxidation properties of refractory hafnium and zirconium compounds[J].Journal of the European ceramic society,1999,19:2405-2414.
[2]GASCH M,ELLERBY D,IRBY E,et al.Processing,properties and arc-jet oxidation of hafnium diboride/silicon carbide ultra high temperature ceramics[J].Journal of materials science,2004,39:5925-5937.
[3]MONTEVERDE F,SCATTEIA L.Resistance to thermal shock and to oxidation of metal diborides-SiC ceramics for aerospace application[J].Journal of the American ceramic society,2007,90:1130-1138.
[4]LI W G,YANG F,FANG D N.The temperaturedependent fracture strength model for ultra-high temperature ceramics[J].Acta mechanica sinica,2010,26:235-239.
[5]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Mechanical behavior of zirconium diboride-silicon carbide ceramics at elevated temperature in air[J].Journal of the European ceramic society,2013,33:2889-2899.
[6]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Mechanical behavior of zirconium diboride-silicon carbide-boron carbide ceramics up to 2200℃[J].Journal of the European ceramic society,2015,35:463-476.
[7]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Ultra-high temperature mechanical properties of a zirconium diboride-zirconium carbide ceramic[J].Journal of the American ceramic society,2016,99:597-603.
[8]WANG R Z,LI W G,JI B H,et al.Fracture strength of the particulate-reinforced ultra-high temperature ceramics based on a temperature dependent fracture toughness model[J].Journal of the mechanics and physics of solids,2017,107:365-378.
[9]JIA Y J,LI H J,FENG L,et al.Ablation behavior of rare earth La-modified ZrC coating for SiC-coated carbon/carbon composites under an oxyacetylene torch[J].Corrosion science,2016,104:61-70.
[10]BLUM Y D,MARSCHALL J,HUI D,et al.Thick protective UHTC coatings for SiC-based structures:Process establishment[J].Journal of the American ceramic society,2008,91:1453-1460.
[11]CARNEY C M.Ultra-high temperature ceramic-based composites,comprehensive composite materials II[M].Amsterdam:Elsevier Press,2018:281-292.
[12]LI Q G,WANG Z,SHI G P,et al.In situ reactive fabrication of ZrC-SiC coating on Cf/ZrC-SiC composite[J].Journal of Asian ceramic societies,2015,3:178-182.
[13]REN J C,ZHANG Y L,HU H,et al.Oxidation resistance and mechanical properties of HfC nanowire-toughened ultra-high temperature ceramic coating for SiC-coated C/Ccomposites[J].Applied surface science,2016,360:970-978.
[14]MOON M W,JENSEN H M,HUTCHINSON J W,et al.The characterization of telephone cord buckling of compressed thin films on substrates[J].Journal of the mechanics and physics of solids,2002,50:2355-2377.
[15]LEE A,CLEMENS B M,NIX W D.Stress induced delamination methods for the study of adhesion of Pt thin films to Si[J].Acta materialia,2004,52:2081-2093.
[16]CHARTIER T,MERLE D,BESSON J L.Laminar ceramic composites[J].Journal of the European ceramic society,1995,15:101-107.
[17]LI W G,WANG R Z,LI D Y,et al.A model of temperature-dependent young’s modulus for ultrahigh temperature ceramics[J].Physics research international,2011,2011:1-3.
[18]SNEAD L L,NOZAWA T,KATOH Y,et al.Handbook of SiC properties for fuel performance modelling[J].Journal of nuclear materials,2007,371:329-377.
[19]HAN J C,WANG B L.Thermal shock resistance of ceramics with temperature dependent material properties at elevated temperature[J].Acta materialia,2011,59:1373-1382.
[2]GASCH M,ELLERBY D,IRBY E,et al.Processing,properties and arc-jet oxidation of hafnium diboride/silicon carbide ultra high temperature ceramics[J].Journal of materials science,2004,39:5925-5937.
[3]MONTEVERDE F,SCATTEIA L.Resistance to thermal shock and to oxidation of metal diborides-SiC ceramics for aerospace application[J].Journal of the American ceramic society,2007,90:1130-1138.
[4]LI W G,YANG F,FANG D N.The temperaturedependent fracture strength model for ultra-high temperature ceramics[J].Acta mechanica sinica,2010,26:235-239.
[5]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Mechanical behavior of zirconium diboride-silicon carbide ceramics at elevated temperature in air[J].Journal of the European ceramic society,2013,33:2889-2899.
[6]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Mechanical behavior of zirconium diboride-silicon carbide-boron carbide ceramics up to 2200℃[J].Journal of the European ceramic society,2015,35:463-476.
[7]NEUMAN E W,HILMAS G E,FAHRENHOLTZ W G.Ultra-high temperature mechanical properties of a zirconium diboride-zirconium carbide ceramic[J].Journal of the American ceramic society,2016,99:597-603.
[8]WANG R Z,LI W G,JI B H,et al.Fracture strength of the particulate-reinforced ultra-high temperature ceramics based on a temperature dependent fracture toughness model[J].Journal of the mechanics and physics of solids,2017,107:365-378.
[9]JIA Y J,LI H J,FENG L,et al.Ablation behavior of rare earth La-modified ZrC coating for SiC-coated carbon/carbon composites under an oxyacetylene torch[J].Corrosion science,2016,104:61-70.
[10]BLUM Y D,MARSCHALL J,HUI D,et al.Thick protective UHTC coatings for SiC-based structures:Process establishment[J].Journal of the American ceramic society,2008,91:1453-1460.
[11]CARNEY C M.Ultra-high temperature ceramic-based composites,comprehensive composite materials II[M].Amsterdam:Elsevier Press,2018:281-292.
[12]LI Q G,WANG Z,SHI G P,et al.In situ reactive fabrication of ZrC-SiC coating on Cf/ZrC-SiC composite[J].Journal of Asian ceramic societies,2015,3:178-182.
[13]REN J C,ZHANG Y L,HU H,et al.Oxidation resistance and mechanical properties of HfC nanowire-toughened ultra-high temperature ceramic coating for SiC-coated C/Ccomposites[J].Applied surface science,2016,360:970-978.
[14]MOON M W,JENSEN H M,HUTCHINSON J W,et al.The characterization of telephone cord buckling of compressed thin films on substrates[J].Journal of the mechanics and physics of solids,2002,50:2355-2377.
[15]LEE A,CLEMENS B M,NIX W D.Stress induced delamination methods for the study of adhesion of Pt thin films to Si[J].Acta materialia,2004,52:2081-2093.
[16]CHARTIER T,MERLE D,BESSON J L.Laminar ceramic composites[J].Journal of the European ceramic society,1995,15:101-107.
[17]LI W G,WANG R Z,LI D Y,et al.A model of temperature-dependent young’s modulus for ultrahigh temperature ceramics[J].Physics research international,2011,2011:1-3.
[18]SNEAD L L,NOZAWA T,KATOH Y,et al.Handbook of SiC properties for fuel performance modelling[J].Journal of nuclear materials,2007,371:329-377.
[19]HAN J C,WANG B L.Thermal shock resistance of ceramics with temperature dependent material properties at elevated temperature[J].Acta materialia,2011,59:1373-1382.