Radially one-dimensional hafnium carbide-carbon/carbon networks composites for ultra-high temperature ablation-resistance

2021 ◽  
Vol 185 ◽  
pp. 109443
Author(s):  
Yanqin Fu ◽  
Yulei Zhang ◽  
Jian Zhang ◽  
Guohui Chen ◽  
Tao Li
2021 ◽  
Author(s):  
STEFANO MUNGIGUERRA ◽  
ANSELMO CECERE ◽  
RAFFAELE SAVINO

The most extreme aero-thermo-dynamic conditions encountered in aerospace applications include those of atmospheric re-entry, characterized by hypersonic Mach numbers, high temperatures and a chemically reacting environment, and of rocket propulsion, in which a combusting, high-pressure, supersonic flow can severely attack the surfaces of the motor internal components (particularly nozzle throats), leading to thermo-chemical erosion and consequent thrust decrease. For these applications, Ultra-High-Temperature Ceramics (UHTC), namely transition metal borides and carbides, are regarded as promising candidates, due to their excellent high-temperature properties, including oxidation and ablation resistance, which are boosted by the introduction of secondary phases, such as silicon carbide and carbon fibers reinforcement (in the so-called Ultra-High- Temperature Ceramic Matrix Composites, UHTCMC). The recent European H2020 C3HARME research project was devoted to development and characterization of new-class UHTCMCs for near-zero ablation thermal protection systems for re-entry vehicles and near-zero erosion rocket nozzles. Within the frame of the project and in collaboration with several research institutions and private companies, research activities at the University of Naples “Federico II” (UNINA) focused on requirements definition, prototypes design and test conditions identification, with the aim to increase the Technology Readiness Level (TRL) of UHTCMC up to 6. Experimental tests were performed with two facilities: an arc-jet plasma wind tunnel, where small specimens were characterized in a relevant atmospheric re-entry environment (Fig.1a), and a lab-scale hybrid rocket engine, where material testing was performed with different setups, up to complete nozzle tests, in conditions representative of real propulsive applications (Fig.1b). The characterization of the aero-thermo-chemical response and ablation resistance of different UHTCMC formulations was supported by numerical computations of fluiddynamic flowfields and materials thermal behavior. The UNINA activities provided a large database supporting the achievement of the project objectives, with development and testing of full-scale TPS assemblies and a large-size solid rocket nozzle.


Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1352
Author(s):  
Qian Sun ◽  
Huifeng Zhang ◽  
Chuanbing Huang ◽  
Weigang Zhang

In this paper, we aimed to improve the oxidation and ablation resistance of carbon fiber-reinforced carbon (CFC) composites at temperatures above 2000 °C. C/C–SiC–ZrB2 ultra-high temperature ceramic composites were fabricated through a complicated liquid–solid reactive process combining slurry infiltration (SI) and reactive melt infiltration (RMI). A liquid Si–Zr10 eutectic alloy was introduced, at 1600 °C, into porous CFC composites containing two kinds of boride particles (B4C and ZrB2, respectively) to form a SiC–ZrB2 matrix. The effects and mechanism of the introduced B4C and ZrB2 particles on the formation reaction and microstructure of the final C/C–SiC–ZrB2 composites were investigated in detail. It was found that the composite obtained from a C/C–B4C preform displayed a porous and loose structure, and the formed SiC–ZrB2 matrix distributed heterogeneously in the composite due to the asynchronous generation of the SiC and ZrB2 ceramics. However, the C/C–SiC–ZrB2 composite, prepared from a C/C–ZrB2 preform, showed a very dense matrix between the fiber bundles, and elongated plate-like ZrB2 ceramics appeared in the matrix, which were derived from the dissolution–diffusion–precipitation mechanism of the ZrB2 clusters. The latter composite exhibited a relatively higher ZrB2 content (9.51%) and bulk density (2.82 g/cm3), along with lower open porosity (3.43%), which endowed this novel composite with good mechanical properties, including pseudo-plastic fracture behavior.


Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Ho Seok Kim ◽  
Bo Ram Kang ◽  
Seong Man Choi

To improve the oxidation resistance of carbon composites at high temperatures, hafnium carbide (HfC) and titanium carbide (TiC) ultra-high-temperature ceramic coatings were deposited using vacuum plasma spraying. Single-layer HfC and TiC coatings and multilayer HfC/TiC coatings were fabricated and compared. The microstructure and composition of the fabricated coatings were analyzed using field-emission scanning electron microscopy and energy dispersive X-ray spectroscopy. The coating thicknesses of the HfC and TiC single-layer coatings were 165 µm and 140 µm, respectively, while the thicknesses of the HfC and TiC layers in the HfC/TiC multi-layer coating were 40 µm and 50 µm, respectively. No oxides were observed in any of the coating layers. The porosity was analyzed from cross-sectional images of the coating layers obtained using optical microscopy. Five random areas for each coating layer specimen were analyzed, and average porosity values of approximately 16.8% for the HfC coating and 22.5% for the TiC coating were determined. Furthermore, the mechanical properties of the coating layers were investigated by measuring the hardness of the cross section and surface roughness. The hardness values of the HfC and TiC coatings were 1650.7 HV and 753.6 HV, respectively. The hardness values of the HfC and TiC layers in the multilayer sample were 1563.5 HV and 1059.2 HV, respectively. The roughness values were 5.71 µm for the HfC coating, 4.30 µm for the TiC coating, and 3.32 µm for the HfC/TiC coating.


2008 ◽  
Vol 368-372 ◽  
pp. 1746-1749 ◽  
Author(s):  
Zhi Qiang Cheng ◽  
Chang Ling Zhou ◽  
Ting Yan Tian ◽  
Cheng Gong Sun ◽  
Zhi Hong Shi ◽  
...  

ZrB2-SiC ultra-high temperature ceramics (UHTCs) were pressureless sintered with Y2O3-Al2O3 as the sintering additives. The effects of sintering additive and crystallization annealing on the microstructure and properties of ZrB2-SiC UHTCs were investigated. Sintering was activated by producing liquid phase of Y2O3 and Al2O3. The relative density of sintered ZrB2-20wt%SiC ceramic could reach 96% when the content of sintering additive was 6% and the sintering temperature was 1750°C and its bending strength, Vickers hardness, and fracture toughness were 412 MPa, 13 GPa, and 6.0 MPa•m1/2, respectively. The crystallization annealing can result in YAG phase from grain boundary and enhance the high temperature properties of the UHTCs. The UHTCs have excellent ablation resistance at ultra-high temperatures, and a very low ablation rate of 0.0006 mm/s after ablation for 900s at 2800°C.


2021 ◽  
Vol 11 (1) ◽  
pp. 1-56
Author(s):  
Dewei Ni ◽  
Yuan Cheng ◽  
Jiaping Zhang ◽  
Ji-Xuan Liu ◽  
Ji Zou ◽  
...  

AbstractUltra-high temperature ceramics (UHTCs) are generally referred to the carbides, nitrides, and borides of the transition metals, with the Group IVB compounds (Zr & Hf) and TaC as the main focus. The UHTCs are endowed with ultra-high melting points, excellent mechanical properties, and ablation resistance at elevated temperatures. These unique combinations of properties make them promising materials for extremely environmental structural applications in rocket and hypersonic vehicles, particularly nozzles, leading edges, and engine components, etc. In addition to bulk UHTCs, UHTC coatings and fiber reinforced UHTC composites are extensively developed and applied to avoid the intrinsic brittleness and poor thermal shock resistance of bulk ceramics. Recently, highentropy UHTCs are developed rapidly and attract a lot of attention as an emerging direction for ultra-high temperature materials. This review presents the state of the art of processing approaches, microstructure design and properties of UHTCs from bulk materials to composites and coatings, as well as the future directions.


2013 ◽  
Vol 28 (9) ◽  
pp. 1014-1018 ◽  
Author(s):  
Qian-Guo FAN ◽  
Hong CUI ◽  
Lian-Sheng YAN ◽  
Qiang ZHANG ◽  
Xiang-Li MENG ◽  
...  

2011 ◽  
Vol 170 ◽  
pp. 37-40 ◽  
Author(s):  
Vlastimil Brozek ◽  
Pavel Ctibor ◽  
Dong Ik Cheong ◽  
Seong Ho Yang ◽  
Libor Mastny ◽  
...  

Successful preparation of massive compact bodies from ultra-high temperature ceramics like zirconium carbide, hafnium carbide and their cermets with tungsten matrix with high values of mechanical parameters is difficult. Only limited number of techniques is able to perform it because of their absolutely highest melting points. In our contribution the preparation of these materials by both - hot pressing and plasma spraying techniques is described and chemical processes taking part at the fabrication are studied. Hot-pressed products fabricated at 2000°C and 6 GPa partly react with the internal surface of the BELT-type apparatus. Melting and solidification is taking place at plasma spraying. This process, carried out by water stabilized plasma torch with centerline temperature up to 30 000°C, is joined with undesirable reactions with plasma-forming medium, with oxidation in a turbulent plasma flow and nitridation of free-flight particles. All these chemical processes depend on variety of parameters, such as particle size of the feedstock powders or electric power of the arc. The mentioned parameters are easily controlled. Other, less controllable, factors include trajectory of powder particles in the plasma jet, important for the melting degree as well as for oxidation or nitridation of the powder surface. New knowledge concerning properties of compact ZrC and HfC were obtained.


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