Detailed electrical and mechanical retention characteristics of MoSi2–RSiC composites exhibiting three-dimensional (3D) interpenetrated network structure during long-term high-temperature oxidation process

2016 ◽  
Vol 42 (5) ◽  
pp. 5873-5884 ◽  
Author(s):  
Wen Xie ◽  
Peng-zhao Gao ◽  
Dong-yun Li ◽  
Hua-nan Lv ◽  
Shi-ting Huang ◽  
...  
Keyword(s):  
High Temperature ◽  
Network Structure ◽  
High Temperature Oxidation ◽  
Oxidation Process ◽  
Three Dimensional ◽  
Temperature Oxidation ◽  
Retention Characteristics

High-temperature oxidation process of intermetallic compound Ti-42 at% Al

1993 ◽  
Vol 28 (4) ◽  
pp. 1067-1073 ◽  
Author(s):  
Akito Takasaki ◽  
Kozo Ojima ◽  
Youji Taneda ◽  
Taiji Hoshiya ◽  
Akira Mitsuhashi
Keyword(s):  
High Temperature ◽  
Intermetallic Compound ◽  
High Temperature Oxidation ◽  
Oxidation Process ◽  
Temperature Oxidation

Properties of Sputtered NiCrAlY Used for Protective Gun Tube Coatings

2011 ◽  
Vol 686 ◽  
pp. 613-617
Author(s):  
Jian Zhang ◽  
Cean Guo ◽  
Gang Zhang ◽  
Chong Rui Wang ◽  
Shi Ming Hao
Keyword(s):  
High Temperature ◽  
Oxidation Resistance ◽  
High Temperature Oxidation ◽  
Oxidation Process ◽  
Complex Oxide ◽  
Isothermal Oxidation ◽  
Temperature Oxidation ◽  
Steel Balls ◽  
Steel Substrates ◽  
Micro Indentation

NiCrAlY coatings were deposited on CrNi3MoVA steel substrates by means of magnetron sputtering. The coatings were characterized in terms of their microstructure, hardness, friction coefficient, high-temperature oxidation resistance. Micro-indentation and tribometer testers were employed to measure the mechanical properties of NiCrAlY coatings and CrNi3MoVA steel. The results showed that the hardness of the coatings ranged from 5.7 to 5.9 GPa, with a higher value than that of CrNi3MoVA steel(4.1-4.3 GPa). The coefficient of steady-state friction of the coatings against 45-carbon-steel balls ranged from 0.35 to 0.40, with a lower value than that of CrNi3MoVA steel(0.63-0.68). The isothermal oxidation behavior at 850°C of the coatings were studied in comparison with CrNi3MoVA steel substrates. The results indicated that NiCrAlY coatings substantially increase the high-temperature oxidation resistance of CrNi3MoVA steel and the oxidation process was retarded mainly by the presence of outer complex oxide scales and a continuous Al2O3 inner layer on the coating.

scholarly journals HIGH TEMPERATURE OXIDATION OF TI-6AL-4V ALLOY FABRICATED BY ADDITIVE MANUFACTURING. INFLUENCE ON MECHANICAL PROPERTIES

2020 ◽  
Vol 321 ◽  
pp. 03006
Author(s):  
Antoine CASADEBAIGT ◽  
Daniel MONCEAU ◽  
Jonathan HUGUES
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Additive Manufacturing ◽  
Titanium Alloys ◽  
Oxidation Kinetics ◽  
High Temperature Oxidation ◽  
Effect Of Temperature ◽  
Premature Failure ◽  
Temperature Oxidation

Titanium alloys, such as Ti-6Al-4V alloy, fabricated by additive manufacturing processes is a winning combination in the aeronautic field. Indeed, the high specific mechanical properties of titanium alloys with the optimized design of parts allowed by additive manufacturing should allow aircraft weight reduction. But, the long term use of Ti-6Al-4V alloy is limited to 315 °C due to high oxidation kinetics above this temperature [1]. The formation of an oxygen diffusion zone in the metal and an oxide layer above it may reduce the durability of titanium parts leading to premature failure [2, 3]. In this study, Ti-6Al-4V alloy was fabricated by Electron Beam Melting (EBM). As built microstructure evolutions after Hot Isostatic Pressure (HIP) treatment at 920 °C and 1000 bar for 2h were investigated. As built microstructure of Ti-6Al-4V fabricated by EBM was composed of Ti-α laths in a Ti-β matrix. High temperature oxidation of Ti-6Al-4V alloy at 600 °C of as-built and HIP-ed microstructures was studied. This temperature was chosen to increase oxidation kinetics and to study the influence of oxidation on tensile mechanical properties. In parallel, two other oxidation temperatures, i.e. 500 °C and 550°C allowed to access to the effect of temperature on long-term oxidation.

Arc-Spraying Composite Coatings on Mild Steel for Long-Term High-Temperature Oxidation Protection

2013 ◽  
Vol 690-693 ◽  
pp. 2039-2045
Author(s):  
Zhong Li Zhang ◽  
Qi Shen Wang ◽  
Peng Rao Wei ◽  
Xue Gong
Keyword(s):  
High Temperature ◽  
High Temperature Oxidation ◽  
Protective Coatings ◽  
Steel Substrate ◽  
Composite Coatings ◽  
Arc Spraying ◽  
Al Alloy ◽  
Temperature Oxidation ◽  
Oxidation Protection

An arc-spraying composite coating system for high-temperature oxidation protection is composed of an inner Fe-Cr-Al alloy layer and an Al-Si alloy outer layer. The high-temperature oxidation behavior of the composite coatings on steel substrate was studied during isothermal exposures in air at 900°C. Experiments show that the coatings on steel substrate are not deteriorated and the substrate is protected well, being exposed to high temperatures up to 900°C. Inter diffusion of alloying elements within the protective coatings occur, while the elements, Cr and Al, are also diffusing to the core of the base metal. As test time proceeds, a large number of chromium oxides are generated in situ within the protective coatings, especially close to the coating/substrate interface. The oxides generated increase the bond strength of the coating to the steel substrate, and together with the surface alumina they provide a long-term effective anti-oxidant protection to steel substrate. The results on titanium sponge production site show that the protective coatings on the reactor have provided an effective protection and prolong the lifetime at least forty percent for the reactors.

scholarly journals Strong and Thermostable Boron-Containing Phenolic Resin-Derived Carbon Modified Three-Dimensional Needled Carbon Fiber Reinforced Silicon Oxycarbide Composites with Tunable High-Performance Microwave Absorption Properties

2020 ◽  
Vol 10 (6) ◽  
pp. 1924 ◽  
Author(s):  
Yu Sun ◽  
Yuguo Sun
Keyword(s):  
High Temperature ◽  
Carbon Fiber ◽  
High Temperature Oxidation ◽  
Phenolic Resin ◽  
Three Dimensional ◽  
Silicon Oxycarbide ◽  
Fiber Reinforced ◽  
Absorption Properties ◽  
Temperature Oxidation ◽  
Carbon Fiber Reinforced

This paper focuses on the preparation of boron-containing phenolic resin (BPR)-derived carbon modified three-dimensional (3D) needled carbon fiber reinforced silicon oxycarbide (SiOC) composites through a simple precursor infiltration and pyrolysis process (PIP), and the influence of PIP cycle numbers on the microstructure, mechanical, high-temperature oxidation resistance. The electromagnetic wave (EMW) absorption properties of the composites were investigated for the first time. The pyrolysis temperature played an important role in the structural evolution of the SiOC precursor, as temperatures above 1400 °C would cause phase separation of the SiOC and the formation of silicon carbide (SiC), silica (SiO2), and carbon. The density and compressive strength of the composites increased as the PIP cycle number increased: the value for the sample with 3 PIP cycles was 0.77 g/cm3, 7.18 ± 1.92 MPa in XY direction and 9.01 ± 1.25 MPa in Z direction, respectively. This composite presented excellent high-temperature oxidation resistance and thermal stability properties with weight retention above 95% up to 1000 °C both under air and Ar atmosphere. The minimal reflection loss (RLmin) value and the widest effective absorption bandwidth (EAB) value of as-prepared composites was −24.31 dB and 4.9 GHz under the optimization condition for the sample with 3 PIP cycles. The above results indicate that our BPR-derived carbon modified 3D needled carbon fiber reinforced SiOC composites could be considered as a promising material for practical applications.

A THERMO-DAMAGE STRENGTH MODEL FOR THE SiC-DEPLETED LAYER OF ULTRA-HIGH-TEMPERATURE CERAMICS ON HIGH TEMPERATURE OXIDATION

2013 ◽  
Vol 05 (03) ◽  
pp. 1350026 ◽  
Author(s):  
RUZHUAN WANG ◽  
WEIGUO LI ◽  
DAINING FANG
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Fracture Strength ◽  
High Temperature Oxidation ◽  
Oxidation Process ◽  
High Porosity ◽  
Strength Model ◽  
Temperature Oxidation ◽  
Ultra High Temperature Ceramics ◽  
Ultra High Temperature

At high temperatures above 1650°C, the SiC -depleted layer of ultra-high-temperature ceramics which has high porosity appears during the oxidation process. In this present paper, based on the studies of the oxidative mechanisms and the fracture mechanisms of ultra-high-temperature ceramics under normal and high temperatures, a thermo-damage strength model for the SiC -depleted layer on high temperature oxidation was proposed. Using the model, the phase transformation, microstructure development and fracture performance in the SiC -depleted layer on high temperature oxidation were studied in detail. The study showed that the porosity is mainly related to the oxidation of SiC . And while the SiC is substantially completely oxidized, only a very small part of matrix is oxidized. The fracture strength of the SiC -depleted layer degrades seriously during the high temperature oxidation process. And the bigger the initial volume fraction of SiC , the lower the fracture strength of the SiC -depleted layer is. This layer may become the origin of failure of material, thus the further researches should be undertaken to improve the oxidation behavior for the ultra-high-temperature ceramics in a wider temperature range.

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