scholarly journals Effect of thermal cycles on mechanical properties of a moderately weathered granite

2021 ◽  
Vol 861 (7) ◽  
pp. 072146
Author(s):  
X H Bao ◽  
H J Zhang ◽  
Q Zhu ◽  
S Feng ◽  
J Q Jia ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Cycles ◽  
Weathered Granite

High Temperature Mechanical Properties of Ni-YSZ Cermets for SOFC Anode

2010 ◽  
Author(s):  
Fumitada Iguchi ◽  
Hiromichi Kitahara ◽  
Hiroo Yugami
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Flexural Strength ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Strain Diagram ◽  
Thermal Cycles ◽  
High Temperature Mechanical Properties ◽  
Sofc Anode ◽  
The Difference

The mechanical properties of Ni-YSZ cermets at high temperature in reduction atmosphere were evaluated by the four points bending method. We studied the influences of reduction and thermal cycles, i.e. a cycle from R.T. to 800°C, to flexural strength and Young’s modulus. The flexural strength of Ni-YSZ at room temperature was lower than that of NiO-YSZ by about 10 to 20% mainly caused by the increment of porosity. But, the flexural strength of Ni-YSZ at 800°C was drastically decreased by an half of that at R.T. In addition, the stress–strain diagram of Ni-YSZ at 800°C indicated that it showed weak ductility. The maximum observed strain was over 0.5% at 30MPa. On the contrary, NiO-YSZ showed only brittlely at 800°C. The difference was caused by Ni metal in the Ni-YSZ cermets. Therefore, it was expected that Ni-YSZ is easily deformed in operation, though residual stress between an anode and an electrolyte was low. The influence of thermal cycles to flexural strength and Young’s modulus was not observed clearly. At the same time, the differences of microstructure were not observed. Therefore, it was concluded that the cycle does not change mechanical properties significantly.

Classification of Engineering Properties of Tropical Boulder in Completely Weathered Granite in Johor, Malaysia

2020 ◽  
Vol 17 (2) ◽  
pp. 1059-1069
Author(s):  
Mohd Firdaus Md Dan ◽  
Edy Tonnizam Mohamad ◽  
Ibrahim Komoo ◽  
Aziman Madun ◽  
Siti Norsalkini Mohd Akip Tan
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Uniaxial Compressive Strength ◽  
Point Load ◽  
Engineering Properties ◽  
Dry Density ◽  
Petrographic Analysis ◽  
Point Load Strength ◽  
Weathered Granite ◽  
Completely Weathered Granite

Engineering properties of tropical weathered granite mass have been widely investigated and classified for engineering purposes. However, the engineering properties of tropical boulder in weathered granite profile is poorly understood and not well classified. This study aims to examine and classify the physico-mechanical properties of granite boulder in completely weathered zone. A total of 34 in-situ boulders were examined from two granite quarries located in Southern Johor, Malaysia. Microstructure-mineralogical alterations were analyzed based on petrographic analysis and scanning electron microscopy (SEM). The mechanical properties were including dry density, porosity, point load strength, uniaxial compressive strength and permeability. Three properties were identified as significant indicators to differentiate between tropical boulder and completely weathered granite when it is evaluated from the soil investigation drilling work namely; texture characteristics, discolourations and degree of weathering. Analysis revealed that the alteration of microstructures and minerals such as feldspar, biotite, and plagioclase from corestone (Grade I/II) to saprolite (Grade IV/V) zone were significantly reduced the dry density, point load strength, uniaxial compressive strength and permeability with 32%, 99.5%, 98.6% and 84.8%, respectively. It has also significantly increased the porosity up to 11.6 times or 1065% from corestone to saprolite. The significant different of physico-mechanical properties of material surrounding boulder due to weathering can be classified and useful in evaluation of geotechnical design and geological engineering applications.

Effect of thermal cycles in electron beam welding of aluminium 1570 alloy on mechanical properties of welded joints

2021 ◽  
Vol 2021 (5) ◽  
pp. 35-40
Author(s):  
V.M. Nesterenkov ◽  
◽  
V.V. Skryabinskyi ◽  
M.O. Rusynyk ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Welded Joints ◽  
Electron Beam Welding ◽  
Thermal Cycles

Effects of thermal cycles on mechanical properties of an optimized polymer concrete

2011 ◽  
Vol 25 (8) ◽  
pp. 3540-3549 ◽  
Author(s):  
M.M. Shokrieh ◽  
M. Heidari-Rarani ◽  
M. Shakouri ◽  
E. Kashizadeh
Keyword(s):  
Mechanical Properties ◽  
Polymer Concrete ◽  
Thermal Cycles

Thermal Cycling Effect on Mechanical Properties, Grain Size and Residual Stress in Alumina and Yttria-Stabilized Tetragonal Zirconia

2014 ◽  
Vol 875-877 ◽  
pp. 1642-1646
Author(s):  
Jing Zhang
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Grain Size ◽  
Thermal Cycling ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Tetragonal Zirconia ◽  
Thermal Cycles ◽  
Optical Applications ◽  
Increasing Temperature

Alumina and zirconia are important materials for energy and optical applications. In this study, the effect of thermal cycling on grain size and residual stress was reported. Residual stress was measured using X-ray diffraction (XRD) sin2ψ method for the as-received and the samples after thermal cycling up to 900 cycles. For alumina, the measured residual stress is approximately 96 MPa in tensile for the as-received material, and increases to its highest value of 480 MPa after 650 thermal cycles. The residual stress decreases from 480 MPa to 96 MPa in tensile with increased thermal cycling from 650 to 900 cycles. The crystallized grain size calculated from the diffraction pattern shows that the mean crystallized grain size is about 93 nm for the as-received and increases to 232 nm after 650 thermal cycles. This result is consistent with the enlarged grain size observed by scanning electron microscopy for the alumina after 650 thermal cycles reported earlier. With continued thermal cycling up to 900 cycles, the crystallized grain size is greatly reduced to 104 nm. It suggests that evolution of the crystallized grain size is correlated with the residual stress. For yttria-stabilized tetragonal zirconia (Y-TZP), the mechanical properties at room temperature, are consistent with the property values provided by the manufacturer. The Young’s modulus of shows a non-linear inverse relationship with increasing temperature. The degradation of the Young’s modulus mostly occurs prior to 400 °C and to a less extent in the temperature range of 400 °C up to 850 °C. The Vickers hardness number for the as-received Y-TZP material decreases to a very small extent after 560 thermal cycles and increases approximately 2%, after 1200 thermal cycles. This is consistent with the trend of the Young’s modulus for thermal-cycled specimens.

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