The Study on Oxidation Resistance of SiC Composites Used for Solar Absorber Coating

2014 ◽  
Vol 887-888 ◽  
pp. 488-492
Author(s):  
Xiao Hong Xu ◽  
Zheng Gang Rao ◽  
Jian Feng Wu
Keyword(s):  
Weight Gain ◽  
Oxidation Resistance ◽  
Bending Strength ◽  
Oxidation Products ◽  
Oxidation Rate Constant ◽  
Promising Candidate ◽  
Good Oxidation Resistance ◽  
Solar Absorber ◽  
Dry Pressing ◽  
Sic Composites

The SiC composites with good oxidation resistance were fabricated via semi-dry pressing and pressureless firing in the air. The SiC, talc, kaolin, alumina, BN and H3BO3were used as starting materials. Sample B2 fired at 1280 °C had the optimal physical properties with a bending strength of 85.84 MPa. Sample B3 contained 1 wt% H3BO3and fired at 1300 °C for 2 h had the best oxidation resistance. After oxidized at 1000 °C for 50 h, the weight gain and oxidation rate constant of sample B3 were 3.3990 mg/cm2and 0.52×10-4g2/(cm4·s) respectively. The oxidation products of SiC, BN and H3BO3could generate SiO2-B2O3film and improve the oxidation resistance effectively. It is believed that these SiC composites should be a promising candidate in solar absorber coating.

Oxidation Behavior of Tantalum Boride Ceramics

2007 ◽  
Vol 124-126 ◽  
pp. 819-822 ◽  
Author(s):  
Junichi Matsushita ◽  
Geum Chan Hwang ◽  
Kwang Bo Shim
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Oxidation Behavior ◽  
Surface Film ◽  
Oxidation Time ◽  
Oxidation Temperature ◽  
Weight Changes ◽  
Good Oxidation Resistance ◽  
Resistant Layer

The oxidation behavior of tantalum diboride (TaB2) powder at high temperature was investigated in order to determine the possibility of the use of advanced high temperature structural materials. Unfortunately, monolithic TaB2 were known to be chemical stability up to high temperatures. To date, there have been few reports regarding the properties of TaB2 ceramics. The samples were oxidized at room temperature to 1273 K for 5 minutes to 25 hours in air. The weight changes were measured to estimate the oxidation resistance. The oxidation of samples oxidized for short oxidation time of 5 minutes started at 873 K, and the weight gain increased with increasing oxidation temperature. On the other hand, at the oxidation time of above 1 hour, a maximum weight gain value at 973 to 1073 K was observed. However, even if the oxidation temperature was increased an additional weight change slightly occurred. The weight gain of the sample oxidized at 1273 K for 5 minutes to 25 hours was about 40 to 20 % of the theoretical oxidation mass change. According to the powder X-ray diffraction date, the oxidized TaB2 sample was changed to Ta2O5 at 873 K. Finally, the TaB2 showed a good oxidation resistance at high temperature, because the surface film of tantalum oxide (Ta2O5) formed by oxidation acted as an oxidation resistant layer.

Isothermal Oxidation Behavior of Ni Base Superalloy DM02 for High Temperature Dies

2007 ◽  
Vol 546-549 ◽  
pp. 1253-1256
Author(s):  
Qing Li ◽  
Jin Xia Song ◽  
Cheng Bo Xiao ◽  
Shi Yu Qu ◽  
Ding Gang Wang ◽  
...  
Keyword(s):  
Weight Gain ◽  
High Temperature ◽  
Oxide Scale ◽  
Oxidation Resistance ◽  
Growth Mechanism ◽  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Good Oxidation Resistance ◽  
Base Superalloy

The isothermal oxidation behavior of a new developed Ni base superalloy named DM02 for high temperature dies was studied in this paper. The dynamic curve was achieved by monitoring weight gain of the alloy as a function of time. The results showed that the alloy had fairly good oxidation resistance at 1050°C and 1100°C. The oxidation kinetics at both 1050°C and 1100°C followed parabolic rules in segment. It has been found that the oxidation of the alloy was controlled by multi-oxides of (Ni, Co)O, (Ni, Co)Al2O4, and NiWO4, growth mechanism in the primary stage, and by Al2O3, NiAl2O4 growth mechanism in the following stage. After oxidation at 1050°C for 100h, the oxide scale of the alloy was mainly composed of two areas. Some were thin uniform (Ni， Co)Al2O4(outer)/Al2O3 (inner) composites scale and others were multi-layer oxide scale of ( Ni,Co)O / multi-oxides (mainly NiWO4、NiO and NiAl2O4.) /Al2O3.

High Temperature Cyclic Oxidation of Coatings on Ni-Based Superalloys

2015 ◽  
Vol 226 ◽  
pp. 137-142
Author(s):  
Marta Kianicová ◽  
Jaroslav Trník
Keyword(s):  
Oxidation Resistance ◽  
Cyclic Oxidation ◽  
Oxidation Products ◽  
Thermo Gravimetric ◽  
Good Oxidation Resistance ◽  
Heating And Cooling ◽  
University Of Technology ◽  
Al Coating ◽  
Kinetics Of ◽  
Cylindrical Samples

The cyclic oxidation behavior of diffusion protective Al and SiAl coatings used on Ni-superalloy namely MAR-M247 at 1100°C for 38 cycles in the air under cyclic heating and cooling conditions has been investigated in the present work. Cyclic oxidation test was carried out in laboratories of Silesian University of Technology in Katowice, Poland. Cylindrical samples were casted from mentioned alloy in factory PBS Velká Bíteš, a.s., Czech Republic. The oxidation kinetics of coated and uncoated superalloys was analyzed by thermo-gravimetric technique. It was observed that all the coated and bare superalloys obey a parabolic rate law of oxidation. SEM/EDX techniques were used to analyses the oxidation products of all samples. MAR-M247 with Al coating showed good oxidation resistance due to the formation of a compact and adhesive thin Al2O3 scale on the surface of the coating during oxidation. SiAl coating showed equally good oxidation resistance. The oxidation progress of uncoated alloy MAR-M247 was very fast.

Study on High Temperature Coating of Cf/SiC Composites

2014 ◽  
Vol 1058 ◽  
pp. 257-260
Author(s):  
Yan Yan Wang ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Rui Xiang Liu ◽  
Kai Jiang
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
Ceramic Coating ◽  
Good Combination ◽  
Composite Matrix ◽  
Good Oxidation Resistance ◽  
Temperature Environment ◽  
Shock Resistance ◽  
Sic Composites ◽  
High Temperature Environment

Cf/SiC composite are widely used in aerospace, chemical industry, traffic, and many other fields because of good mechanical properties, heat resistance, thermal shock resistance and abrasion resistance, corrosion resistance, etc. But its oxidation resistance is poor in the application of high temperature environment. In this paper, high-temperature ceramic coating was prepared on Cf/SiC composites surface through brush painting method and the oxidation resistance of the coating were studied. The coating was tested by XRD, SEM, etc. The results showed that the coating and composite matrix is good combination, at the same time the coating has good oxidation resistance.

Fabrication of Mullite Coating and its Oxidation Protection for Carbon Fiber Reinforced SiC Composites

2016 ◽  
Vol 697 ◽  
pp. 476-480 ◽  
Author(s):  
Kuan Hong Zeng ◽  
Qing Song Ma ◽  
Li Hui Cai
Keyword(s):  
Carbon Fiber ◽  
Flexural Strength ◽  
Oxidation Resistance ◽  
Dip Coating ◽  
Solid Content ◽  
Fiber Reinforced ◽  
Good Oxidation Resistance ◽  
Mullite Coating ◽  
Carbon Fiber Reinforced ◽  
Sic Composites

To protect carbon fiber-reinforced SiC (C/SiC) composites against oxidation,mullite coating was prepared on C/SiC composites by dip-coating method with high solid content Al2O3-SiO2 sol as raw materials. X-ray diffraction and scanning electron microscopy were employed to analyze the phase and microstructure of the coating. The results show that the as-prepared coating is SiO2-rich, monolithic and well bonded with substrate without penetrating crack, giving rise to good oxidation-resistance. After soaked at 1400°C for 30min under static air, the coated C/SiC composites possess 87% of original flexural strength. As a result of sealing and filling of cracks and pores by viscous SiO2 in coating, the coated C/SiC composites exhibit improved oxidation resistance at 1500°C and 1600°C. There is no change in flexural strength after oxidized at 1500°C and 1600°C for 30min, respectively. Nevertheless, the carbothermal reduction between viscous SiO2 and free carbon in C/SiC substrate would occur obviously when oxidation temperature was elevated or oxidation time was prolonged, leading to local foaming in coating and decreasing in oxidation resistance.

Improved Oxidation Resistance of SiС-Based Ceramic Matrix Composites by In Situ Reaction with Si3N4 Filler

2012 ◽  
Vol 512-515 ◽  
pp. 775-778
Author(s):  
Bin Wu ◽  
Zhen Wang ◽  
Shao Ming Dong
Keyword(s):  
Phase Composition ◽  
Oxidation Resistance ◽  
Bending Strength ◽  
Ceramic Matrix Composites ◽  
Ceramic Matrix ◽  
Matrix Composites ◽  
Three Point Bending ◽  
Sic Composites ◽  
Polymer Infiltration

SiC-Si3N4 powders and modified SiC-based ceramic matrix composites (CMCs) were fabricated using polycarbosilane (PCS), divinylbenzene (DVB) and Si3N4 filler. Si3N4 was introduced into CMCs fabricated through polymer infiltration and pyrolysis (PIP) to lower down the carbon content by in-situ carbothermal reaction, which derived from pyrolyzed PCS-DVB. The oxidation resistance and three point bending strength of modified C/SiC composites were effectively enhanced. The phase composition, microstructure of SiC-Si3N4 powders and modified C/SiC composites were investigated by XRD, SEM and TEM.

scholarly journals High-Temperature Oxidation Behavior of a Cu-Bearing 17Cr Ferritic Stainless Steel

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Mengqi Zhang ◽  
Ying Han ◽  
Guoqing Zu ◽  
Jiapeng Sun ◽  
Weiwei Zhu ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Weight Gain ◽  
Oxidation Resistance ◽  
Ferritic Stainless Steel ◽  
Oxidation Kinetics ◽  
Oxidation Behavior ◽  
Isothermal Oxidation ◽  
Element Distribution ◽  
Temperature Oxidation ◽  
Good Oxidation Resistance

The isothermal oxidation behavior of 17Cr-0.85Si-0.5Nb-1.2Cu ferritic stainless steel in air was studied from 850°C to 1050°C by analyzing its weight gain after oxidation. The kinetic curves were plotted using the oxidation weight-gain data, and the structure, surface morphology, and element distribution of the oxide films were analyzed by XRD, SEM, and EDS. The results showed that the oxidation kinetics curves at 850°C and 950°C followed a parabolic law, and a continuous and dense oxide film composed of Cr2O3 and MnCr2O4, FeCr2O4, and Cu-Cr rich spinel was formed, which reveals that the steel displayed good oxidation resistance. When the temperature was increased to 1050°C, the oxidation kinetics curves gradually changed from parabolic to linear after 40 h exposure, which indicated that the oxidation resistance significantly worsened. A lower oxidation resistance was observed at 1050°C due to the formation of a large amount of Fe2O3 on the surface and the volatilization of the inner Cr2O3 layer.

scholarly journals Effect of Al2O3 and SiO2 Inert-Fillers on the Microstructural Evolution and High Temperature Oxidation Resistance of B Modified Silicides Coatings Prepared by Pack Cementation Technology

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 700
Author(s):  
Linfen Su ◽  
Guanqun Zhuo ◽  
Haiwen Song ◽  
Jianyong Yang ◽  
Kaiyong Jiang
Keyword(s):  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Process ◽  
Pack Cementation ◽  
Oxidation Products ◽  
Initial Oxidation ◽  
Temperature Oxidation ◽  
Good Oxidation Resistance ◽  
Inert Filler ◽  
Oxidation Stage

In this study, B modified silicide coatings were prepared on Nb-Si based alloy with Al2O3 or SiO2 inert-filler by pack cementation technology. Both coatings primarily consisted of a (Nb,X)Si2 with a (Nb,X)B2 + (Nb,X)Si2 outer layer. After oxidation at 1250 °C for 100 h, the coatings showed good oxidation resistance due to the formation of a dense silica. The oxidation products of the coating prepared with Al2O3 inert-filler consisted of SiO2, TiO2 and Cr2O3, while that of the coating prepared with SiO2 inert-filler consisted of SiO2, TiO2, Cr2O3, and HfO2. The different oxidation products may be due to the different oxidation process of these two sample at initial oxidation stage.

Phase transformation and layer evolution in molybdenum disilicide-silicon carbide nanolayered coatings

1994 ◽  
Vol 52 ◽  
pp. 538-539
Author(s):  
H. Kung ◽  
T. R. Jervis ◽  
J.-P. Hirvonen ◽  
M. Nastasi ◽  
T. E. Mitchell ◽  
...  
Keyword(s):  
Phase Transformation ◽  
High Temperature ◽  
Oxidation Resistance ◽  
Elevated Temperatures ◽  
Matrix Material ◽  
Molybdenum Disilicide ◽  
High Temperature Strength ◽  
Cross Sectional ◽  
Good Oxidation Resistance ◽  
Structural Applications

MoSi2 is a potential matrix material for high temperature structural composites due to its high melting temperature and good oxidation resistance at elevated temperatures. The two major drawbacksfor structural applications are inadequate high temperature strength and poor low temperature ductility. The search for appropriate composite additions has been the focus of extensive investigations in recent years. The addition of SiC in a nanolayered configuration was shown to exhibit superior oxidation resistance and significant hardness increase through annealing at 500°C. One potential application of MoSi2- SiC multilayers is for high temperature coatings, where structural stability ofthe layering is of major concern. In this study, we have systematically investigated both the evolution of phases and the stability of layers by varying the heat treating conditions.Alternating layers of MoSi2 and SiC were synthesized by DC-magnetron and rf-diode sputtering respectively. Cross-sectional transmission electron microscopy (XTEM) was used to examine three distinct reactions in the specimens when exposed to different annealing conditions: crystallization and phase transformation of MoSi2, crystallization of SiC, and spheroidization of the layer structures.

RA 600

Alloy Digest ◽  
1967 ◽  
Vol 16 (1) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Oxidation Resistance ◽  
Heat Treating ◽  
Chromium Alloy ◽  
Good Resistance ◽  
Good Oxidation Resistance ◽  
Nickel Base

Abstract RA-600 is a nickel-base chromium alloy having good oxidation resistance to 2150 F, and good resistance to carburizing and nitriding atmospheres. It is recommended for furnace construction and equipment. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-120. Producer or source: Rolled Alloys Inc..

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