Tem study of microstructure in relation to hardness and ductility in Al-Mg-Si (6xxx) alloys

Two different solution heat treatments (2hours at 570ºC and 10minutes at 520ºC) have been used to study precipitation in two 6xxx (Al-Mg-si) dispersoid-freealloys with composition: 0.721 at % Si, 0.577 at % Mg (alloy A3) and 0.57 at %Si 0.72 at % Mg (alloy A12). The relation between their microstructure and macroscopical properties such as hardness and ductility has been investigated. Tensile tests, hardness measurements, electrical conductivity sigma tests, grain size measurements in optical microscope and microstructure characterization in Transmission Electron Microscope (TEM) have all been done. The effect of alloy composition and solution heat treatment temperature and time on the microstructure and the resulting macroscopical properties (hardness, yield stress, tensile strength and ductility) was investigated. The results indicate that when alloy A3 is solution treated at 520ºC for 10 minutes and then annealed for 3 hours at 175ºC, its hardness, yield stress and tensile strength as well as ductility is optimised i.e.A3 has better mechanical properties and low cost of production at these conditions. It has been proved that the strengthening was solely due to precipitation particles and not grain size

Tem study of microstructure in relation to hardness and ductility in Al-Mg-Si (6xxx) alloys

Two different solution heat treatments (2hours at 570ºC and 10minutes at 520ºC) have been used to study precipitation in two 6xxx (Al-Mg-si) dispersoid-freealloys with composition: 0.721 at % Si, 0.577 at % Mg (alloy A3) and 0.57 at %Si 0.72 at % Mg (alloy A12). The relation between their microstructure and macroscopical properties such as hardness and ductility has been investigated. Tensile tests, hardness measurements, electrical conductivity sigma tests, grain size measurements in optical microscope and microstructure characterization in Transmission Electron Microscope (TEM) have all been done. The effect of alloy composition and solution heat treatment temperature and time on the microstructure and the resulting macroscopical properties (hardness, yield stress, tensile strength and ductility) was investigated. The results indicate that when alloy A3 is solution treated at 520ºC for 10 minutes and then annealed for 3 hours at 175ºC, its hardness, yield stress and tensile strength as well as ductility is optimised i.e.A3 has better mechanical properties and low cost of production at these conditions. It has been proved that the strengthening was solely due to precipitation particles and not grain size

Numerical study of copper antimony sulphide (CuSbS2) solar cell by SCAPS-1D

Copper antimony sulphide thin films are promising, less toxic, and more absorbent material in the world, and they would be good to be applied in photovoltaic energy production. To better operations of copper antimony sulphide (CuSbS2) photovoltaic cells, this paper uses a solar cell capacitance simulator (SCAPS-1D) to simulate and analyze photovoltaic properties. This article examines different thicknesses of fluorine-doped tin oxide (FTO), cadmium sulphide (CdS), carbon (C), and CuSbS2, as well as the defect and dopant concentration in the CuSbS2 photoactive layer of the photovoltaic cell structure glass/FTO/n-CdS/p-CuSbS2/C/Au. Optimum thicknesses of CuSbS2 is 300 nm, carbon hole transport layer (HTL) is 50 nm, and for n-CdS electron transport layer (ETL) is 100 nm, giving open circuit Voltage (Voc) of 0.9389 V, short circuit current density (Jsc) of 28.32 mA/cm2, fill factor (FF) of 60.8% and solar cell efficiency of 16.17%. The increase in defects causes a decrease of carrier lifetime resulting in to decrease in diffusion length and the optimum absorber layer doping concentration was found to be 1018 cm−3

Thickness Dependence of Window Layer on CH3NH3PbI3-XClX Perovskite Solar Cell

CH3NH3PbI3-xClx has been studied experimentally and has shown promising results for photovoltaic application. To enhance its performance, this study investigated the effect of varying thickness of FTO, TiO2, and CH3NH3PbI3-xClx for a perovskite solar cell with the structure glass/FTO/TiO2/CH3NH3PbI3-xClx/Spiro-OMeTAD/Ag studied using SCAPS-1D simulator software. The output parameters obtained from the literature for the device were 26.11 mA/cm2, 1.25 V, 69.89%, and 22.72% for Jsc, Voc, FF, and η, respectively. The optimized solar cell had a thickness of 100 nm, 50 nm, and 300 nm for FTO, TiO2, and CH3NH3PbI3-xClx layers, respectively, and the device output were 25.79 mA/cm2, 1.45 V, 78.87%, and 29.56% for Jsc, Voc, FF, and η, respectively, showing a remarkable increase in FF by 8.98% and 6.84% for solar cell efficiency. These results show the potential of fabricating an improved CH3NH3PbI3-xClx perovskite solar cell

Accurate Ab-initio calculation of elastic constants of anisotropic binary alloys: A case of Fe–Al

International audienc

Thermal properties and pressure-dependent elastic constants of cadmium stannate as a substrate for MEMS: An ab initio study

International audienceSilicon carbide (SiC) has become a suitable replacement to silicon as a substrate for manufacture of microelectromechanical systems (MEMS) that operate in harsh environmental conditions, owing to its better mechanical properties such as excellent wear resistance. However, just like silicon, SiC is also brittle, a property that limits its application as a substrate for manufacture of flexible MEMS. In this study, we explored the thermal properties as well as the pressure-dependent elastic constants of cadmium stannate (Cd2SnO4) for the first time within the quantum espresso code. The result showed that the elastic constants of SiC are much higher than those of Cd2SnO4. The properties of SiC were found to be more sensitive to the applied pressure compared those of Cd2SnO4, implying that it is less mechanically and thermally stable with the applied pressure compared to Cd2SnO4, and therefore, less appealing compared to Cd2SnO4 for the manufacture of most MEMS

Mechanical Properties of Al–Mg–Si Alloys (6xxx Series): A DFT-Based Study

Al–Mg–Si alloys are used in aircraft, train, and car manufacturing industries due to their advantages, which include non-corrosivity, low density, relatively low cost, high thermal and electrical conductivity, formability, and weldability. This study investigates the bulk mechanical properties of Al–Mg–Si alloys and the influence of the Si/Mg ratio on these properties. The Al cell was used as the starting structure, and then nine structures were modeled with varying percentages of aluminium, magnesium, and silicon. Elastic constant calculations were conducted using the stress–strain method as implemented in the quantum espresso code. This study found that the optimum properties obtained were a density of 2.762 g/cm3, a bulk modulus of 83.3 GPa, a shear modulus of 34.4 GPa, a Vickers hardness of 2.79 GPa, a Poisson’s ratio of 0.413, a Pugh’s ratio of 5.42, and a yield strength of 8.38 GPa. The optimum Si/Mg ratio was found to be 4.5 for most of the mechanical properties. The study successfully established that the Si/Mg ratio is a critical factor when dealing with the mechanical properties of the Al–Mg–Si alloys. The alloys with the optimum Si/Mg ratio can be used for industrial applications such as plane skins and mining equipment where these properties are required