scholarly journals Influence of heating to high temperatures on mechanical properties of boride-based refractory materials

2021 ◽  
Vol 2 (1(58)) ◽  
pp. 21-25
Author(s):  
Anastasiia Lokatkina ◽  
Tetiana Prikhna ◽  
Viktor Moshchil ◽  
Pavlo Barvitskyi ◽  
Oleksandra Borimsky ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperatures ◽  
Mechanical Characteristics ◽  
Aerospace Industry ◽  
Initial Mixture ◽  
Refractory Materials ◽  
Melting Temperatures ◽  
Before And After ◽  
Sintered Materials

The object of research is HfB2, ZrB2 and ceramics composition HfB2-30 % SiC and ZrB2-20 % SiC, ZrB2-20 % SiC-4 % Si3N4 obtained under high pressure, their mechanical characteristics before and after heating to high temperatures and temperatures of beginning of melting. The research was conducted in order to create new effective refractory materials for use in the aerospace industry. Therefore, the melting temperatures of sintered materials and the effect of heating on their mechanical properties were also studied. Additives (ZrB2-20 % SiC and HfB2-30 % SiC) although led to a decrease in specific gravity. But increased hardness (by 17 % and 46 % in the case of ZrB2 and HfB2, respectively) and fracture toughness (by 40 % and 21 % in the case of ZrB2 and HfB2, respectively). However, significantly reduced the onset of melting temperature in vacuum to 2150–2160 °C. Materials sintered from ZrB2 and HfB2 was not melted after heating to 2970 °C. After heating to a melting point of 2150–2160 °C (in the case of materials with additives) and to temperatures of 2970 °C (in the case of materials sintered with ZrB2 or HfB2), the hardness and fracture toughness decreased. Thus, the hardness of the material prepared from ZrB2 decreased by 19 % and its fracture toughness – by 18 %, and of that prepared from ZrB2–20 % SiC – by 46 % and 32 %, respectively. The hardness of the material prepared from HfB2 decreased by 46 %, its fracture toughness – by 55 %, and of that prepared from HfB2-30 % SiC, after heating decreased by 40 %, but its fracture toughness increased by 15 %. The sintered HfB2 (with a density of 10.4 g/cm3) before heating showed a hardness of HV(9.8 N)=21.27±0.84 GPa, HV(49 N)=19.29±1.34 and HV(98 N)=19.17±0.5, and fracture toughness K1C(9.8 N)=0.47 MH·m0.5, and ZrB2 with a density of 6.2 g/cm3 was characterized by HV(9.8 N)=17.66±0.60 GPa, HV(49 N)=15.25±1.22 GPa and HV(98 N)=15.32±0.36 GPa, K1C(9.8 N)=4.3 MH·m0.5. Material sintered with HfB2-30 % SiC (density 6.21 g/cm3) had Hv(9.8 N)=38.1±1.4 GPa, HV(49 N)=27.7±2.8 GPa, and K1C(9.8 N)=8.1 MH·m0.5, K1C(49 H)=6.8 MH·m0.5. The sintered with ZrB2-20 % SiC material had density of 5.04 g/cm3, HV(9.8 N)=24.2±1.9 GPa, HV(49 N)=16.7±2.8 GPa, K1C(49 H)=7.1 MH·m0.5. The SiC addition to the initial mixture significantly reduces the elasticity of the materials.

CF8C-PLUS

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tensile Properties ◽  
High Temperatures

Abstract CF8C-Plus is an austenitic casting grade similar to CF8C, but with improved chemistry to stay fully austenitic at high temperatures and thus retain good mechanical properties. This datasheet provides information on composition, microstructureand tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on casting and joining. Filing Code: SS-1006. Producer or source: Caterpillar Technical Center.

scholarly journals Влияние содержания корунда и температуры спекания на механические свойства керамических композитов CaO-ZrO-=SUB=-2-=/SUB=--Al-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

2018 ◽  
Vol 44 (4) ◽  
pp. 25 ◽  
Author(s):  
А.А. Дмитриевский ◽  
А.И. Тюрин ◽  
А.О. Жигачев ◽  
Д.Г. Гусева ◽  
П.Н Овчинников
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Mechanical Characteristics ◽  
Vickers Microhardness ◽  
Ceramic Composites ◽  
Optimum Regime ◽  
Two Stage

AbstractWe have studied the mechanical properties (Vickers microhardness H _V and fracture toughness K _C) of nanostructured CaO–ZrO_2–Al_2O_3 ceramic composites as dependent on the content of corundum (0 ≤ $$C_{Al_{2}O_{3}}$$ C A l 2 O 3 ≤ 25%) and the temperature of sintering (1250°C ≤ T _1 ≤ 1500°C). Optimum value of the corundum content ( $$C_{Al_{2}O_{3}}$$ C A l 2 O 3 = 5%) and optimum regime ( T _1 = 1300°C, 5 min; T _2 = 1200°C, 4 h) of two-stage sintering are established, which favor attaining the best mechanical characteristics of ceramic composites ( H _V = 12.25 GPa, K _C = 8.47 MPa m^1/2).

The Effect of the Deformation Method of the Billets on Mechanical Properties of Molybdenum Bars and Wire

2020 ◽  
Vol 864 ◽  
pp. 204-210
Author(s):  
Sergey Gorbatyuk ◽  
Dmitry Efremov ◽  
Sergei Albul ◽  
Natalya Kirillova
Keyword(s):  
Mechanical Properties ◽  
Comparative Analysis ◽  
High Temperatures ◽  
Rolling Mill ◽  
Mechanical Characteristics ◽  
New Technology ◽  
Deformation Resistance ◽  
Helical Rolling ◽  
Deformation Method ◽  
High Deformation

A procedure has been developed for calculating the geometric, kinematic and energy-power parameters of helical rolling, which allows a comparative analysis of the processes carried out in stands of various designs. Based on the results of this analysis, a helical rolling mill was designed and manufactured which allows to roll materials with high deformation resistance at high temperatures. The results of the study of the mechanical characteristics of molybdenum bars and wires made by new technology are presented.

Mechanical Properties of Zirconia/Alumina Nano-Composite after Soaking in Various Water-Based Conditions

2006 ◽  
Vol 309-311 ◽  
pp. 1219-1222 ◽  
Author(s):  
Seiji Ban ◽  
Masahiro Nawa ◽  
Y. Suehiro ◽  
H. Nakanishi
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Tetragonal Zirconia ◽  
Flexure Strength ◽  
Nano Composite ◽  
Dental Restorations ◽  
Dental Restoratives ◽  
All Ceramic ◽  
Water Based ◽  
Before And After

Yttria stabilized tetragonal zirconia polycrystals (Y-TZP) have been applied to dental crown and bridges. Whereas, to further improve its mechanical strength, the zirconia/alumina nano-composite stabilized with cerium oxide (Ce-TZP/Al2O3 nano-composite) was developed. In the present study, biaxial flexure strength, fracture toughness and hardness were determined before and after soaking in water-based conditions and the possibility of application to all ceramic dental restorations was discussed. In comparison to Y-TZP, Ce-TZP/Al2O3 nano-composite has quite high flexure strength and fracture toughness along with satisfied durability for LTAD in various water-based conditions encountered in dentistry. Therefore, it is concluded that the nano-composite can be safely applied to dental restoratives such as all-ceramic bridges.

scholarly journals Silicon carbide liquid-phase sintering with various activating agents

2018 ◽  
pp. 24-30
Author(s):  
S. N. Perevislov ◽  
M. V. Tomkovich ◽  
A. S. Lysenkov
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Liquid Phase ◽  
Mechanical Characteristics ◽  
Solid Phase ◽  
Physical And Mechanical Properties ◽  
Liquid Phase Sintering ◽  
Sintered Materials

The liquid-phase sintering at 1860‒2100 °C was used to prepare the silicon-carbide materials with the 5‒10 weigh percent of oxide additions. The SiC material with the 20 weigh percent of three-component MgO‒Y2O3‒Al2O3system addition showed the ultimate physical and mechanical properties. The mechanical characteristics of the liquidphase sintered materials with the 15 weigh percent of the three-component oxides addition exceed those of both the reactive-sintered and the solid-phase sintered materials and approach to those of the hot-pressed materials.Ill. 5. Ref. 31. Tab. 2.

NICKEL 200

Alloy Digest ◽  
1962 ◽  
Vol 11 (10) ◽  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
Temperature Performance ◽  
Nickel 200

Abstract Nickel-200 is a wrought metal combining excellent mechanical properties with corrosion resistance. It retains its strength to an excellent degree at high temperatures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness and creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-75. Producer or source: Huntington Alloy Products Division.

scholarly journals Investigation of the fluids influence on change of sandstones collectors mechanical properties during saturation and degassing

2019 ◽  
Vol 109 ◽  
pp. 00103
Author(s):  
Serhii Tynyna ◽  
Vasyl Babenko
Keyword(s):  
Mechanical Properties ◽  
Stress State ◽  
Mechanical Characteristics ◽  
Partial Discharge ◽  
Laboratory Studies ◽  
Deformation Properties ◽  
Before And After ◽  
Surface Active ◽  
Sandstone Formation ◽  
State Of The Environment

The article discusses the effect of fluids on the properties of rocks. It is known that surface active environments, including gas, can significantly change the mechanical characteristics of solids. To establish the dependence of the effect of methane on the strength characteristics of rocks, the results of full-scale and laboratory studies are considered. The experiments were carried out on samples of outburst sandstone formation m3, taken at a depth of 915 m. Analysis of research results allowed to establish the effect of changes in gas saturation of rocks on their mechanical properties before and after degassing and partial discharge of experimental areas after they have been worked by lavas along m3 formation. It has been established that the reason for the increase in drillability and strength of sandstones was their degassing, and not a change in the stress state of the environment. This led to a change in the deformation properties of rocks in gas-saturated and degassed states.

A New Method for Determining Strength and Fracture Toughness of Ceramic Materials in Air at 1500-2000 °C

2014 ◽  
Vol 633 ◽  
pp. 447-450 ◽  
Author(s):  
De Tian Wan ◽  
Yi Wang Bao ◽  
Yuan Tian ◽  
Yan Qiu ◽  
Hua Zhao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperatures ◽  
Bending Strength ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Test Method ◽  
Sic Fiber ◽  
Bending Load ◽  
Ceramic Components

Evaluation of the mechanical properties at ultra-high temperatures for ceramic composites is necessary and important for the safety of designing the ceramic components. In this work, a new and novel test method named as local ultra-high temperature together with applied load method (LUHTAL), was developed to determine the tensile, compressive, bending strength and fracture toughness of ceramic composites. The four point bending load was conducted to measure the bending strength and fracture toughness of ceramic composites after the center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. To check the availability and reliability for this method, typical ceramic materials including ZrB2/SiC and C/SiC fiber reinforced composite coated with Si, were used as the testing samples. It is indicated that this method is good and feasible for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures in air.

scholarly journals Mechanical properties of aerospace epoxy composites reinforced with 2D nano-fillers: current status and road to industrialization

2021 ◽  
Author(s):  
Radhika Wazalwar ◽  
Megha Sahu ◽  
Ashok M. Raichur
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Fracture Toughness ◽  
High Performance ◽  
Aerospace Industry ◽  
Epoxy Composites ◽  
Current Status ◽  
High Performance Polymer

Epoxy composites find application in the aerospace industry. Although epoxy is a high-performance polymer, its fracture toughness is compromised due to its highly cross-linked nature. Nanomaterials such as carbon nanotubes...

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