scholarly journals Effect of a Trace Addition of Sn on the Aging Behavior of Al–Mg–Si Alloy with a Different Mg/Si Ratio

Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 913 ◽  
Author(s):  
Lehang Ma ◽  
Jianguo Tang ◽  
Wenbin Tu ◽  
Lingying Ye ◽  
Haichun Jiang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Number Density ◽  
Precipitation Behavior ◽  
Aging Behavior ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Positive Effect ◽  
Room Temperature Tensile Test

In this paper, the effect of trace Sn on the precipitation behavior and mechanical properties of Al–Mg–Si alloys with different Mg/Si ratios aged at 180 °C was investigated using hardness measurements, a room-temperature tensile test, transmission electron microscopy and differential scanning calorimetry. The results shown that Sn reduces the precipitation activation energy, increases the number density of β″ precipitates, and then increased the aging hardenability and mechanical properties of the Al–Mg–Si alloy. However, the positive effect of Sn on the mechanical properties of the Al–Mg–Si alloy drops with the decrease of the Mg/Si ratio of the alloy.

Optimization of Precipitation Phase Type and Mechanical Properties of X2A66 Alloy by Pre-Deformation Treatment

2019 ◽  
Vol 814 ◽  
pp. 268-274
Author(s):  
Mang Jiang ◽  
Rui Chun Guan ◽  
Jin Jun Xu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Aging Temperature ◽  
Room Temperature ◽  
Transmission Electron ◽  
Phase Type ◽  
New Type ◽  
Precipitation Phase ◽  
Room Temperature Tensile Test ◽  
Deformation Treatment

In the present work, the effects of pre-deformation before aging on the precipitation phase and mechanical properties of a new type X2A66 alloy was investigated with the help of the room temperature tensile test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) methods. The experimental research results prove that reducing the aging temperature or pre-deformation before aging is beneficial to improve the mechanical properties of the alloy. Compared with decreased aging temperature, pre-deformation treatment before aging can significantly improve the mechanical properties of the alloy, and its yield strength (YS), ultimate tensile strength (UTS) and elongation are 593.4Mpa, 610.8Mpa, and 10.7%, respectively.

Effects of Thermal Treatment on the Morphology and Properties of CSM/Poly(Urethane-Isocyanurate) Composites Formed by SRIM Process

2008 ◽  
Vol 575-578 ◽  
pp. 941-946
Author(s):  
Hong Yan Tang ◽  
Ji Hui Wang ◽  
Guo Qiang Gao ◽  
Wen Xing Chen
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Treatment Time ◽  
Microphase Separation ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Scanning Electron

Fiberglass continuous strand mat(CSM)/poly(urethane-isocyanurate) composites were formed by SRIM process, treated under different conditions and then characterized based on dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) ,transmission electron microscopy (TEM) and the mechanical property tests. The results show that the mechanical properties of the composites could be increased with improving the degree of microphase separation. At a given temperature (120°C), the degree of microphase separation is the highest for 4h and decreases gradually with prolonging treatment time. For a given time (4h), the well microphase-separated morphology is obtained and the degree of microphase mixing is increased at 120°C and 140°C treatments, respectively. The degree of microphase separation of the composites decreases with enhancing the temperature to 140°C.

Preparation of Al2O3/Al-Si Composites by In Situ Reaction of Fe2O3+MnO2/Al System

2015 ◽  
Vol 816 ◽  
pp. 48-53
Author(s):  
Jing Zhang ◽  
Hua Shun Yu ◽  
Xin Ting Shuai ◽  
Hong Mei Chen ◽  
Guang Hui Min
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Electron Probe ◽  
Room Temperature ◽  
Manganese Content ◽  
Hardness Test ◽  
Test Results ◽  
Electron Probe Micro Analyzer ◽  
Transmission Electron ◽  
Polygonal Shape

Al2O3 particles reinforced ZL109 composites were prepared by in-situ reaction between Fe2O3+MnO2 and Al in this paper. The influence of ratio of Mn to Fe on the morphologies of Al-Si-Mn-Fe phase and mechanical properties of the composites was investigated. The microstructure was studied by electron probe micro-analyzer (EPMA) and transmission electron microscopy (TEM). The results show that the Al2O3 particles displaced by the Fe2O3+MnO2/Al system are in nanosize. The acicular Al-Si-Fe phases change from acicular to polygonal shape and become smaller with the increase manganese content. The hardness test results have no big difference on the composites. However, the ultimate tensile strength at room temperature and 350°C enhance evidently with the increasing of Mn/Fe.

Room Temperature Synthesis of Cu2O Nanospheres: Optical Properties and Thermal Behavior

2014 ◽  
Vol 21 (1) ◽  
pp. 108-119 ◽  
Author(s):  
Daniela Nunes ◽  
Lídia Santos ◽  
Paulo Duarte ◽  
Ana Pimentel ◽  
Joana V. Pinto ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Behavior ◽  
Room Temperature ◽  
Diffuse Reflectance Spectroscopy ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron

AbstractThe present work reports a simple and easy wet chemistry synthesis of cuprous oxide (Cu2O) nanospheres at room temperature without surfactants and using different precursors. Structural characterization was carried out by X-ray diffraction, transmission electron microscopy, and scanning electron microscopy coupled with focused ion beam and energy-dispersive X-ray spectroscopy. The optical band gaps were determined from diffuse reflectance spectroscopy. The photoluminescence behavior of the as-synthesized nanospheres showed significant differences depending on the precursors used. The Cu2O nanospheres were constituted by aggregates of nanocrystals, in which an on/off emission behavior of each individual nanocrystal was identified during transmission electron microscopy observations. The thermal behavior of the Cu2O nanospheres was investigated with in situ X-ray diffraction and differential scanning calorimetry experiments. Remarkable structural differences were observed for the nanospheres annealed in air, which turned into hollow spherical structures surrounded by outsized nanocrystals.

Grain Refinement of Pure Copper by ECAP

2008 ◽  
Vol 584-586 ◽  
pp. 393-398 ◽  
Author(s):  
Nayar Lugo ◽  
Jose María Cabrera ◽  
Núria Llorca-Isern ◽  
C.J. Luis-Pérez ◽  
Rodrigo Luri ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Grain Refinement ◽  
Strain Distribution ◽  
Room Temperature ◽  
Pure Copper ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Homogeneous Strain

Pure commercial Cu of 99,98 wt % purity was processed at room temperature by Equal- Channel Angular Pressing (ECAP) following route Bc. Heavy deformation was introduced in the samples after a considerable number of ECAP passes, namely 1, 4, 8, 12 and 16. A significant grain refinement was observed by transmission electron microscopy (TEM). Tensile and microhardness tests were also carried out on the deformed material in order to correlate microstructure and mechanical properties. Microhardness measurements displayed a quite homogeneous strain distribution. The most significative microstructural and mechanical changes were introduced in the first ECAP pass although a gradual increment in strength and a slight further grain refinement was noticed in the consecutive ECAP passes.

The effects of combined cyclic close die forging and aging process on microstructure and mechanical properties of AA7075

2020 ◽  
Vol 234 (9) ◽  
pp. 1242-1251
Author(s):  
MA Moazam ◽  
M Honarpisheh
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Crack Formation ◽  
Experimental Tests ◽  
Ultimate Tensile Stress ◽  
X Ray ◽  
Die Forging ◽  
Transmission Electron ◽  
Processed Sample

It is well known that applying severe plastic deformation methods on the precipitation hardenable aluminum alloys at room temperature is very difficult because of crack formation and segmentation of the specimen during the processes. In this study, several procedures were experimentally examined for performing the cyclic close die forging (CCDF) and improving the mechanical properties of AA7075. The experimental tests revealed that supersaturated solid solution of AA7075 after water quenching is formable for only about 5 min and performing the CCDF process in this limited time is possible. Optical and scanning electron microscopy and transmission electron microscopy were used to study the microstructure of the processed samples. It was observed that by applying two passes of CCDF, the grain size of the material reduced from 30 µm to about 200–300 nm. In addition, the X-ray diffractometer results demonstrated that Guinier–Preston zone picks of the processed samples are very weak and the equilibrium η-phase does not exist in none of the suggested procedures. Furthermore, it was found that by combining CCDF and aging processes according to the proposed procedures, the mechanical properties of the processed AA7075 were improved when compared with the AA7075-T6. To put it more clearly, micro-hardness, yield strength and ultimate tensile stress of the processed sample were improved as much as 38.6%, 25% and 23%, respectively.

Annealing Effects in Nanograined Al-Cu-Mg Alloy Processed by Equal Channel Angular Pressing

2017 ◽  
Vol 748 ◽  
pp. 240-244
Author(s):  
Hassan Houcin Ktari ◽  
Jean Philippe Couzine ◽  
Julie Bourgon ◽  
Yannick Champion ◽  
Nabil Njah
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Activation Energy ◽  
Equal Channel Angular Pressing ◽  
Mg Alloy ◽  
Scanning Calorimetry ◽  
Angular Pressing ◽  
Secondary Precipitation ◽  
Transmission Electron ◽  
Annealing Effects

The microstructure and mechanical properties were investigated in an industrial Al-Cu-Mg alloy processed by Equal Channel Angular Pressing ECAP and heating. The die used is formed by two channels intersecting at an angle 90°. Transmission Electron Microscopy (TEM) and orientation (ASTAR) imaging were used in addition to hardness measurements. After heating, a sub-micron grain size is retained. In addition, a further hardening is observed due to secondary precipitation. Differential Scanning Calorimetry (DSC) showed that the activation energy of θ’ precipitation is strongly lowered after ECAP.

scholarly journals Microstructure Evolution and Mechanical Properties of PM-Ti43Al9V0.3Y Alloy

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 198 ◽  
Author(s):  
Dongdong Zhang ◽  
Na Liu ◽  
Yuyong Chen ◽  
Guoqing Zhang ◽  
Jing Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Electron Backscattered Diffraction ◽  
Tial Alloys ◽  
Fine Grain ◽  
Transmission Electron ◽  
Novel Strategy ◽  
Room Temperature Strength

A novel strategy of microstructure design is introduced to improve the mechanical properties of TiAl alloys, fabricated by powder metallurgy. The gas atomization powder and as-HIPed (Hot isostatic pressing) TiAl are investigated by scanning electron microscopy, energy dispersive spectrometry, transmission electron microscopy, and electron backscattered diffraction. The dispersed submicron precipitate in the microstructure is determined to be Y2O3. A microstructure with uniform fine grain is obtained. The room temperature strength and strain reach 793 MPa and 1.5%, respectively. The strength and strain at 700 °C are still as high as 664 MPa and 9.2%, respectively. The fine grain and precipitate lead to a high room-temperature plasticity.

scholarly journals FEATURES OF STRUCTURE FORMATION AND CHANGES IN THE MECHANICAL PROPERTIES OF CAST Al-Mg-Si-Mn ALLOY WITH THE ADDITION OF (Ti+Zr)

2015 ◽  
Vol 55 (4) ◽  
pp. 282 ◽  
Author(s):  
Oleksandr Trudonoshyn ◽  
Maxim Puchnin ◽  
Kostiantyn Mykhalenkov
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Ageing Time ◽  
Tensile Tests ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Heat Treated ◽  
Scanning Electron

<p>The as-cast and heat-treated structure of permanent mould castings of AlMg<sub>5</sub>Si<sub>2</sub>Mn alloys with different contents of Ti has been investigated by differential scanning calorimetry, hardness and microhardness measurements, tensile tests and fractography analyses, scanning electron microscopy, transmission electron microscopy, and energy dispersive X-ray analysis. We have established that α-Al dendrites can be nucleated on an Al-Ti substrate, and also that primary Mg<sub>2</sub>Si crystals can be nucleated on oxides, including oxides of Al and Ti compounds. The dependence of the change in mechanical properties on ageing time, and on the amount of Ti in the alloys, is shown.</p>

Reinforcing Effects of Poly(D-Lactide)-g-Multiwall Carbon Nanotubes on Polylactide Nanocomposites

2015 ◽  
Vol 15 (10) ◽  
pp. 8086-8092 ◽  
Author(s):  
Jeong Hee Yang ◽  
Jae Yun Lee ◽  
In-Joo Chin
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Testing Machine ◽  
Multiwall Carbon Nanotubes ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

Polylactide (PLA) nanocomposites with multi-walled carbon nanotubes (MWNTs) grafted with poly(L-lactide) or poly(D-lactide) were prepared by solution casting, and their thermal and mechanical properties were evaluated. MWNTs containing hydroxyl groups were treated by ring-opening polymerization of either L-lactide or D-lactide. Fourier transform infrared spectroscopy confirmed that the MWNT surfaces had been modified by the PLLA or PDLA chains. The thermal properties were measured by differential scanning calorimetry and thermogravimetric analysis. The mechanical properties were examined using a universal testing machine. The morphology of the fractured surfaces of the PLA nanocomposites was observed by scanning electron microscopy and transmission electron microscopy. PDLA-g-MWNTs were dispersed more uniformly compared to PLLA-g-MWNTs in the PLA matrix. The incorporation of PDLA-g-MWNTs greatly improved the tensile strength of the nanocomposites regardless of the contents. Thermal analysis revealed different characteristics at specific composites depending on the type of modification.

Sign in / Sign up

Export Citation Format

Share Document