Effect of Annealing Time on Properties of Cr/NbCr2 Alloy

2015 ◽  
Vol 1089 ◽  
pp. 65-69
Author(s):  
Li Ping Deng ◽  
Shi Qiang Lu ◽  
Xuan Xiao ◽  
Ke Lu Wang
Keyword(s):  
Solid Solution ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Relative Density ◽  
Vickers Hardness ◽  
Annealing Time ◽  
Room Temperature ◽  
Compression Tests ◽  
Compression Properties ◽  
Maximum Value

Cr/NbCr2 alloy containing with 91at.%Cr and 9at.% Nb was prepared by mechanical alloying and hot pressing .Then it was annealing at 1200°C for10h, 30h,50h,100h ,respectively in vacuum condition. The results show that the relative density of Cr/NbCr2 alloy increases slightly with the annealing time. Meanwhile, Vickers hardness of Cr/NbCr2 alloy decreases with the annealing time. After annealing at 1200 °C for 100 h, the relative density and Vickers hardness of Cr/NbCr2 alloy vary from 98.9% to 99.7% and 5.6 GPa to 3.78 GPa, respectively. Due to the good plasticity of chromium solid solution, obvious plastic deformation appears during room temperature compression tests. After annealing at 1200°C for 10h, the compression properties of Cr/NbCr2 alloy, such as compressive strength, yield strength and strain, get the maximum value.

Dynamic and Quasi-Static Compressive Deformation Behaviour of Polyimide Foam at Various Elevated Temperature

2014 ◽  
Vol 566 ◽  
pp. 158-163 ◽  
Author(s):  
A. Yosimoto ◽  
Hidetoshi Kobayashi ◽  
Keitaro Horikawa ◽  
Keiko Watanabe ◽  
Kinya Ogawa
Keyword(s):  
Compressive Strength ◽  
Room Temperature ◽  
Deformation Behaviour ◽  
Testing Machine ◽  
Negative Temperature ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Universal Testing ◽  
Pressure Bar

In order to clarify the effect of strain rate and test temperature on the compressive strength and energy absorption of polyimide foam, a series of compression tests for the polyimide foam with two different densities were carried out. By using three testing devices, i.e. universal testing machine, dropping weight machine and sprit Hopkinson pressure bar apparatus, we performed a series of compression tests at various strain rates (10-3~103s-1) and at several test temperatures in the range of room temperature to 280 ̊C. At over 100 s-1, the remarkable increase of flow stress was observed. The negative temperature dependence of strength was also observed.

scholarly journals Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Phase Composition ◽  
Low Temperature ◽  
Uniaxial Compression ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Influence of High Temperatures on the Mechanical Properties of Wood Bio-Concretes

2022 ◽  
Author(s):  
Amanda Lorena Dantas Aguiar ◽  
M’hamed Yassin Rajiv da Gloria ◽  
Romildo Dias Toledo Filho
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperatures ◽  
Room Temperature ◽  
Plant Biomass ◽  
Compression Tests ◽  
Wood Degradation ◽  
Cementitious Matrix ◽  
Wood Shavings ◽  
Temperature Reference

The use of wood wastes in the production of bio-concrete shows high potential for the development of sustainable civil construction, since this material, in addition to having low density, increases the energy efficiency of buildings in terms of thermal insulation. However, a concern arising from the production of bio-concretes with high amounts of plant biomass is how this material behaves when subjected to high temperatures. Therefore, this work aims to evaluate the influence of high temperatures on the mechanical properties of wood bio-concretes. The mixtures were produced with wood shavings volumetric fractions of 40, 50 and 60% and cementitious matrix composed of a combination of cement, fly ash and metakaolin. Uniaxial compression tests and scanning electron microscopy (SEM) were performed, with bio-concrete at age of 28 days, at room temperature (reference) and after exposure to temperatures of 100, 150, 200 and 250 °C. The density and compressive strength of the bio-concrete gradually decreased with increasing biomass content. Up to 200 °C, reductions in strength and densities less than 19% and 13%, respectively, were observed. At 250 °C, reductions of compressive strength reached 87%. Analysis performed by SEM showed an increase in the number of cracks in the wood-cementitious matrix interface and wood degradation by increasing the temperature.

scholarly journals Microstructure and Compression Properties of VSS-V3B2 Eutectic Alloys in the V-Si-B System

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2100 ◽  
Author(s):  
Christopher Müller ◽  
Georg Hasemann ◽  
Maximilian Regenberg ◽  
Ulf Betke ◽  
Manja Krüger
Keyword(s):  
Room Temperature ◽  
Phase Region ◽  
Ternary Alloys ◽  
Compression Tests ◽  
Compression Properties ◽  
Eutectic Trough ◽  
Binary Eutectic ◽  
Strength And Plasticity ◽  
Multi Phase ◽  
The Impact

The present study reports on the microstructural evolution and room temperature plasticity of V(-Si)-B alloys with respect to the V solid solution (VSS)-V3B2 phase region. To investigate the occurring effects systematically, different binary V-B and ternary V-Si-B alloys were produced by conventional arc melting. Scanning electron microscope (SEM) analyses and X-ray diffraction (XRD) measurements were used to characterize the resulting as-cast microstructures. For the first time, the eutectic composition was systematically traced from the binary V-B domain to the ternary V-Si-B system. The observations discover that the binary eutectic trough (VSS-V3B2) seems to reach into the ternary system up to an alloy composition of V-5Si-9B. Room temperature compression tests were carried out in order to study the impact of single-phase and multi-phase microstructures on the strength and plasticity of binary and ternary alloys. The results indicate that the VSS phase controls the plastic deformability in the VSS-V3B2 eutectic microstructure whereas the intermetallic V3B2 acts as a strong hardening phase.

Current States and Development of Research on Redissolution and Reprecipitation of Nanoprecipitated Phases in Al–Cu Alloys

2019 ◽  
Vol 11 (11) ◽  
pp. 1489-1501
Author(s):  
Wenjing He ◽  
Caihe Fan ◽  
Shu Wang ◽  
Junhong Wang ◽  
Su Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
Supersaturated Solid Solution ◽  
Aluminum Matrix ◽  
Aging Treatment ◽  
Cu Alloys ◽  
The Reformation

The evolution of nanoprecipitated phases in Al–Cu alloys under severe plastic deformation (SPD) is summarized in this study. SPD at room temperature induces the precipitation of Al–Cu alloys to dissolve, leading to the reformation of supersaturated solid solution in the aluminum matrix. In the process of SPD or aging treatment after the SPD, the reprecipitated phases are precipitated from the aluminum matrix and the mechanical properties of the alloys are remarkably improved. The mechanism and system of the redissolution of the precipitation phases and the effects of redissolution and reprecipitation on the microstructure and properties of Al–Cu alloys are comprehensively analyzed. The development and future of redissolution and reprecipitation of nanoprecipitated phases in Al–Cu alloys are also described.

Effects of Elevated Temperatures on the Compression Strength of Nanoclay Filled Unsaturated Polyester Resin

2014 ◽  
Vol 554 ◽  
pp. 208-212 ◽  
Author(s):  
M.S. Fartini ◽  
M.S. Abdul Majid ◽  
Mohd Afendi ◽  
N.A.M. Amin ◽  
Azizul Mohamad
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Unsaturated Polyester ◽  
Polyester Resins ◽  
Weight Percentage ◽  
Compression Properties ◽  
Strain Behaviour ◽  
Compressive Tests

The paper describes the effects of the montmorillonite (MMT) fillers commonly known as nanoclay, on the compression properties of unsaturated polyester resins at different weight percentage of nanoclay. Modified resin specimens with 1, 3 and 5 wt. % of nanoclay contents were prepared and subjected to compressive tests according to ASTM D695. The static uniaxial compression testing were conducted at various temperatures ranging from room temperature (RT) to the temperature closer to its glass transition temperature Tg to study the effect of nanoclay fillers on the compressive stress-strain behaviour at high temperatures (room temperature, 35, 45, and 75°C). The mechanical properties of the nanomodified resin including the elastic modulus, maximum stress and failure strain were determined. The experimental results imply that adding these nanoclay fillers has enhanced the elastic modulus, compressive strength, and toughness without sacrificing the strain to failure and thermal stability of the unsaturated polyester. However it was found that generally, all specimens showed degradation in compressive strength with increases in temperatures.

Compaction of Ti-6Al-4V Powder by ECAE with Back-Pressure

2007 ◽  
Vol 29-30 ◽  
pp. 33-36 ◽  
Author(s):  
Rimma Lapovok ◽  
Dacian Tomus ◽  
Barry C. Muddle
Keyword(s):  
Powder Metallurgy ◽  
Hydrostatic Pressure ◽  
Relative Density ◽  
Shear Deformation ◽  
Vickers Hardness ◽  
Room Temperature ◽  
Low Cost ◽  
Hot Isostatic Pressing ◽  
Back Pressure ◽  
Angular Pressing

Powder metallurgy is widely used to produce alloys with low cost of production. The main drawback using powders is the level of residual porosity of final product which often implies the application of a complicated and costly hot isostatic pressing process. However, this issue can be overcome by using equal channel angular pressing (ECAE) with back pressure (BP). The use of severe shear deformation, with imposed hydrostatic pressure, allows a reduction in the range of compaction temperatures compare to those used in conventional practice. The compaction of Ti-6Al-4V powder by the ECAE method has been investigated. The compaction has been performed at temperatures starting from room temperature (RT) and increasing up to 400°C with various back pressures ranging from 0 to 350MPa. A billet processed by ECAE with 43MPa back-pressure at 400°C was found to have improved relative density of 97.5% and increased Vickers hardness of 369HV, compared to values of 96.7% and 325HV respectively obtained at RT. A relative density of 98.2% and 426HV hardness were measured for billets processed with BP = 262MPa at 400°C. A fully compact billet was obtained by applying 350 MPa of BP at 400°C.

Microstructures and Mechanical Properties of Mg Alloy after Severe Torsion Straining Process

2006 ◽  
Vol 503-504 ◽  
pp. 949-954 ◽  
Author(s):  
Yuichi Miyahara ◽  
N. Emi ◽  
Koji Neishi ◽  
Katsuaki Nakamura ◽  
Kenji Kaneko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Refinement ◽  
Room Temperature ◽  
Rotation Speed ◽  
Continuous Process ◽  
Mg Alloy ◽  
Compression Tests ◽  
Moving Speed ◽  
Az61 Mg Alloy

Grain refinement is attempted using severe plastic deformation (SPD) through the severe torsion straining process (STSP) which we have developed recently. The STSP is a continuous process for grain refinement without requirement of any die. In this study, an AZ61 Mg alloy was subjected to STSP at a temperature of 573 K with a rotation speed of 10 rpm and a moving speed of 200 mm/min. With this process, an initial grain size of ~20 μm was reduced to ~2~3 μm. Room temperature compression tests revealed that there were no cracks after 15% of compression for the STSP sample whereas fracture occurred for a conventionally extruded sample. For compression tests at 473 K, no cracks occurred in the STSP samples after 80% compression but compression was feasible without cracking only up to 20% for an extruded sample. It is shown that the STSP can be useful for grain refinement and ductility improvement of the AZ61 Mg alloy.

Effect of Nano-Clay and their Dispersion Techniques on Compressive Properties of Unsaturated Polyester Resin

2014 ◽  
Vol 554 ◽  
pp. 27-31 ◽  
Author(s):  
M.S. Fartini ◽  
M.S. Abdul Majid ◽  
Mohd Afendi ◽  
R. Daud ◽  
Azizul Mohamad
Keyword(s):  
Compressive Strength ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Processing Parameters ◽  
Unsaturated Polyester Resin ◽  
Compression Tests ◽  
Compressive Properties ◽  
Polyester Resins ◽  
Compression Properties ◽  
Nanoclay Content

This paper aims to understand the relationship between processing parameters and compressive properties of nanoclay filled polyester resin (dispersion method and wt% of nanoclay particles). Unsaturated polyester resin with 0-5 wt% nanoclay content was prepared by hand mixing and through shears mixing of water bath shaker. Static uniaxial compression tests were conducted to investigate how the unsaturated polyester resins with nanoclay contents and processing will effect on the compressive stress-strain behaviour and compression properties. The experimental results show that the compressive strength and elastic modulus of nanomodified resin are significantly affected by type of mixing methods to prepare the specimens and the ratio of nanoparticles content during mixing. It was found out that the compressive strength and compressive modulus increase with the nanoclay content. The findings also indicate the dispersion of nanoclay by hand-mixed method yield higher compressive strength compared to that dispersed by water shaker bath.

Annealing Study of Al-Mg Wrought Alloys Using Two Different Techniques and Estimation of the Activation Enthalpy of Migrating Defects

2013 ◽  
Vol 337-338 ◽  
pp. 29-37
Author(s):  
Ahmed G. Attallah ◽  
M.A. Abdel-Rahman ◽  
M. El-Sayed ◽  
A.A. Ibhraim ◽  
S.A. Aly ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Electrical Resistivity ◽  
Annealing Time ◽  
Room Temperature ◽  
Isothermal Annealing ◽  
Activation Enthalpy ◽  
Full Recovery ◽  
Mg Alloy ◽  
Annealing Study

The electrical resistivity and the corresponding mechanical properties (hardness) of some 5xxx Al-Mg alloy processed by plastic deformation were investigated. Plastic deformation was performed at room temperature. Isothermal annealing produced a significant change in both the electrical and mechanical properties of the samples. As the annealing time was increased, the resistivity and hardness up to full recovery. The activation enthalpy of migration of defects was determined, was found to be 0.234±0.06 eV, 0.218±0.049 eV, 0.316±0.016 eV 0.232±0.012 eV for 5005, 5251, 5052 and 5754 alloys, respectively.

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