共查询到18条相似文献,搜索用时 171 毫秒
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采用重力分离SHS制备了钢管内衬Al2O3涂层,进行了力学、抗热震、耐蚀等性能测试,研究了管径、装料密度及不同含量SiO2、CrO3添加剂对涂层组织与性能的影响。研究结果表明,涂层主要物相结构为α-Al2O3+FeAl2O4相,添加剂SiO2和CrO3不改变涂层的主要相组成。反应过程中熔融金属Fe在钢管基体和内衬陶瓷层之间形成了一层金属过渡层。当添加2%SiO2+6%CrO3时,涂层孔隙率最小,硬度最大,抗热震性能最好,耐蚀性也较好,具有良好的综合性能。实验条件下,管径25cm、装料密度1.5g/cm3的内衬涂层硬度为1917HV,孔隙率为9.0%。 相似文献
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以SiO2、Fe2O3、Cr2O3、MnO2为原料按比例混合,经固相高温烧结制备成基体粉料,再与粘结剂混合球磨制备出高温红外辐射节能涂料。通过XRD、半球点测试仪、红外辐射测量仪、纳米粒度测试仪对材料的微观结构和理化性能进行了表征,采用热震法对涂层的抗热震性能进行了研究。研究结果表明,随着平均粒径的减小,合成的SiO2-Fe2O3-Cr2O3-MnO2体系全波段红外辐射率有明显增大的趋势。当平均粒径达到2μm左右时,涂料全波段红外辐射率最高达到0.93。涂料的最高使用温度达1400℃以上,涂层的抗热震性能良好。此外,在燃气梭式干燥窑上使用该高温红外辐射节能涂料后,降低能耗15%左右,抗老化性能优良,使用一年后辐射率仍在0.90以上。 相似文献
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The microstructure and composition of TiC-A12O3/Fe functionally graded materials (FGM) prepared by self-propagating high temperature synthesis and pseudo-hot isostatic pressing (SHS/ PHIP) were studied, and the resisting thermal shock behaviors were analyzed. The results show that TiC-A12O3/Fe FGM has graded composition distribution. No cross-section crack through the layers was found in the tests of thermal shock and fatigue. 相似文献
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H. Hamatani N. Shimoda S. Kitaguchi 《Science and Technology of Advanced Materials》2013,14(2):197-203
Low Pressure Plasma Spraying (LPPS) is a promising coating method for Functionally Graded Material (FGM) expected to beable to reduce the thermal stress in high temperature environments such as a gas turbine. In this paper, we report the effect of the composition profile and coating density of LPPS sprayed FGM, consisting of ZrO2–8 wt%Y2O3 (YSZ) top coating, YSZ–Ni–20 wt%Cr (NiCr) FGM coating, NiCr under coating and copper substrate, on the thermal shock resistance evaluated by a modified temperature difference test. The density of YSZ and NiCr coating was successfully controlled by the chamber pressure and initial particle size in the range from 5.43 to 5.79 g/cm3 and from 7.89 to 8.09 g/cm3, respectively. For an YSZ composition profile from NiCr under coating to YSZ top coating (in FGM), the highest thermal shock resistance was obtained when the fraction of YSZ increased with gentleslope just over NiCr coating and acute slope just under YSZ coating. Also, the higher density coatings tended to perform the higher thermal shock resistance. Initial cracks formed in the YSZ top coating propagated into YSZ parts in FGM coating through the grain boundary of YSZ and/or the interface between flattened NiCr and YSZ particles. After the cracks connected, the coupled cracks caused the coating spallation.©2003 Elsevier Science Ltd. All rights reserved. 相似文献
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《Science and Technology of Advanced Materials》2003,4(2):197-203
Low Pressure Plasma Spraying (LPPS) is a promising coating method for Functionally Graded Material (FGM) expected to be able to reduce the thermal stress in high temperature environments such as a gas turbine. In this paper, we report the effect of the composition profile and coating density of LPPS sprayed FGM, consisting of ZrO2–8 wt%Y2O3 (YSZ) top coating, YSZ–Ni–20 wt%Cr (NiCr) FGM coating, NiCr under coating and copper substrate, on the thermal shock resistance evaluated by a modified temperature difference test. The density of YSZ and NiCr coating was successfully controlled by the chamber pressure and initial particle size in the range from 5.43 to 5.79 g/cm3 and from 7.89 to 8.09 g/cm3, respectively. For an YSZ composition profile from NiCr under coating to YSZ top coating (in FGM), the highest thermal shock resistance was obtained when the fraction of YSZ increased with gentle slope just over NiCr coating and acute slope just under YSZ coating. Also, the higher density coatings tended to perform the higher thermal shock resistance. Initial cracks formed in the YSZ top coating propagated into YSZ parts in FGM coating through the grain boundary of YSZ and/or the interface between flattened NiCr and YSZ particles. After the cracks connected, the coupled cracks caused the coating spallation. 相似文献
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采用热键合技术制备了Yb:Y3Al5O12/Y3Al5O12(Yb:YAG/YAG)复合晶体,对复合晶体进行了结构表征和键合质量检测.利用光学显微镜和扫描电镜观察了复合晶体横截面的形貌;在偏光显微镜下观察键合区域的应力,利用干涉条纹来表征复合晶体的光学均匀性;通过红外透过光谱的测量来检测复合晶体的键合质量.实验结果表明:热键合技术制备的Yb:YAG/YAG复合晶体键合界面处无界面缺陷,不存在复合界面空间过渡层,光学均匀性良好. 相似文献
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The thermal residual stress in the fabrication of functionally graded material (FGM) systems can give rise to various mechanical failures. For a FGM system under a given fabrication environment, the thermal residual stresses are determined by the spatial distribution of its constituent components. In this study, we optimize a Ni/Al2O3 FGM plate aiming at minimizing the thermal residual stresses through controlling its compositional distribution. Material properties are graded in the thickness direction following a power law distribution in terms of the volume fractions of constituents (P-FGM). An analytical model and a hybrid genetic algorithm with the pattern search are employed to predict and to minimize the thermal residual stresses, respectively. Simulation results show that an optimal design of the FGM plate could help fulfill its potential in reducing the thermal residual stresses. 相似文献