Microstructure Evolution and Properties of 7A56 Aluminum Alloy by Homogenization

2017 ◽  
Vol 898 ◽  
pp. 153-158 ◽  
Author(s):  
Da Xu ◽  
Zhi Hui Li ◽  
Guo Jun Wang ◽  
Long Bing Jin ◽  
Hong Wei Yan ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Microstructure Evolution ◽  
Equilibrium Phase ◽  
Hardness Test ◽  
Homogenization Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Second Phases ◽  
Al Matrix

The microstructure evolution and properties of Al-matrix in homogenized 7A56 alloy were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC), electrical conductivity and hardness test. The second phases in as-cast 7A56 alloy consisted of AlZnMgCu, Al2Cu and Al7Cu2Fe. With the homogenization temperature increasing, more non-equilibrium phase AlZnMgCu was dissolved into Al-matrix. The diffusion of alloying elements from AlZnMgCu phase into Al-matrix leads to a decrease of electrical conductivity and an increase of hardness. The lattice constant of α-Al has an increases of 0.0019 Å, 0.0032 Å and 0.0053 Å after 380°C/24h,430°C/24h,and 470°C/24 h treatment,respectively.

Microstructure Evolution of a Fine Grain Al-50wt%Si Alloy Fabricated by High Energy Milling

2011 ◽  
Vol 479 ◽  
pp. 54-61 ◽  
Author(s):  
Fei Wang ◽  
Ya Ping Wang
Keyword(s):  
Grain Growth ◽  
Microstructure Evolution ◽  
Room Temperature ◽  
Milling Time ◽  
High Energy ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Laser Method ◽  
X Ray ◽  
Fine Grain

Microstructure evolution of high energy milled Al-50wt%Si alloy during heat treatment at different temperature was studied. Scanning electron microscope (SEM) and X-ray diffraction (XRD) results show that the size of the alloy powders decreased with increasing milling time. The observable coarsening of Si particles was not seen below 730°C in the high energy milled alloy, whereas, for the alloy prepared by mixed Al and Si powders, the grain growth occurred at 660°C. The activation energy for the grain growth of Si particles in the high energy milled alloy was determined as about 244 kJ/mol by the differential scanning calorimetry (DSC) data analysis. The size of Si particles in the hot pressed Al-50wt%Si alloy prepared by high energy milled powders was 5-30 m at 700°C, which was significantly reduced compared to that of the original Si powders. Thermal diffusivity of the hot pressed Al-50wt%Si alloy was 55 mm2/s at room temperature which was obtained by laser method.

Influence of Plasticizers on the Electrical Conductivity of Polyacrylonitrile (PAN)/Lithium-Montmorillonite (Li-MMT) Polymer Composite Electrolyte

2017 ◽  
Vol 894 ◽  
pp. 89-93
Author(s):  
Mitch Irene Kate N. Galvan ◽  
Leslie Joy L. Diaz
Keyword(s):  
Electrical Conductivity ◽  
Polymer Composite ◽  
Electrochemical Impedance ◽  
Current Trend ◽  
Xrd Analysis ◽  
Dimethyl Formamide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Composite Electrolyte ◽  
X Ray

With the current trend of miniaturization and portability of electronic gadgets, the development of polymer composite electrolyte (PCE) gained much research interest. In this study PAN matrix was plasticized with various dimethyl formamide (DMF)/ propylene carbonate (PC) ratios. X-ray diffraction (XRD) analysis revealed that both DMF and PC reduce the crystallinity of PAN. Yet, films with higher amount of PC caused much decrease in crystallinity, which is indicated by lowering of full with at half maximum (FWHM) at the utmost 57% when the DMF/PC ratio is 1:2. Differential scanning calorimetry (DSC) analysis also revealed that glass transition temperature (Tg) of PAN decreased from 83.34°C to 50.27°C when plasticized with pure DMF and to temperature lower than ambient condition when PC alone was used. Upon incorporation of 15 wt% Li-MMT, PCEs with pure DMF exhibited the highest electrical conductivity, which is 3.6x10-8 S/cm based on electrochemical impedance spectroscopy (EIS). This suggests that the electrical conductivity is not dictated by the decrease on polymer host crystallinity alone. The type of plasticizer and appropriate combination was shown to have an effect wherein the plasticizer that causes higher degree of solvation and has lower boiling point is thought to provide more hopping sites for electrons due to higher amount of broken bonds in the nitrile group of PAN.

DSC AND ELECTRICAL CONDUCTIVITY STUDIES ON SUPERIONIC ALL-GLASS PHOSPHATE-BASED COMPOSITES

2011 ◽  
Vol 04 (02) ◽  
pp. 139-142
Author(s):  
JAN L. NOWIŃSKI ◽  
WIOLETA ŚLUBOWSKA ◽  
JERZY E. GARBARCZYK ◽  
MAREK WASIUCIONEK
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Phosphate Glasses ◽  
Superionic Conductors ◽  
X Ray Diffraction ◽  
Glass Composite ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dsc Studies

The work investigates electrical properties of all-glass composite Ag +-ion conductors based on silver phosphate glasses. A combination of X-ray diffraction (XRD) and differential scanning calorimetry (DSC) was used for characterization of the samples. The impedance spectroscopy (IS) was applied to determine the electrical conductivity in a wide temperature range (from -140 to +20°C). Results of the DSC studies indicate that all-glass materials prepared from the powdered glasses are bi-phasic. On the other hand their electrical properties resemble homogeneous rather than heterogeneous superionic conductors.

scholarly journals The Effect of Increased Cu Content on Microstructure and Melting of Utilized Sn-0.3Ag-0.7Cu Solder

2018 ◽  
Vol 26 (43) ◽  
pp. 33-44
Author(s):  
Marián Drienovský ◽  
Lýdia Rízeková Trnková ◽  
Roman Čička ◽  
Pavol Priputen ◽  
Marcela Pekarčíková ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Cu Content ◽  
Soldering Process ◽  
Wave Soldering ◽  
Thermo Calc Software ◽  
Temperature Dependences ◽  
Free Solder

Abstract The influence of increased Cu and Ag contents on the microstructure evolution in the utilized Sn-0.3Ag-0.7Cu (wt. %) solder was studied. The utilized solder was exploited in the wave soldering process at the temperatures of about 260 °C for several days. The samples investigation involved the differential scanning calorimetry, the scanning electron microscopy including the energy dispersive X-ray spectroscopy, and the X-ray diffraction techniques. To predict phase equilibria at various temperatures and temperature dependences of heat capacity, the Thermo-Calc software and the COST531 lead-free solder database were used. The original and the utilized solders were found to be very similar regarding the phase occurrence, but slightly differ from one another in microstructure evolution due to higher bulk contents of Cu in the latter solder. The obtained results contribute to both the better understanding of the microstructure evolution in low-silver Sn-Ag-Cu solders and the determination of compositional limits for those solders used in the wave soldering process.

Synthesis and characterization of 1,4-diazophenylenebridged Cu-phthalocyanine polymer

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Cemil Alkan ◽  
Leyla Aras ◽  
Güngör Gündüz
Keyword(s):  
Electrical Conductivity ◽  
Diazonium Salt ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Visible Spectroscopy ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Uv Visible ◽  
Soluble Part

Abstract A novel type of phthalocyanine polymer, 1,4-diazophenylene-bridged Cuphthalocyanine, was prepared from the diazonium salt of diaminobenzene and Cu(II) 1,8,15,22-tetraaminophthalocyanine. The polymer is partially soluble in tetrahydrofuran, dichloromethane, and dimethylformamide. Characterization of the polymer was performed by IR and UV-visible spectroscopy, X-ray diffraction, ash analysis, viscometry, differential scanning calorimetry and thermogravimetric analysis. The molecular weight of the soluble part of the polymer was determined by ebullioscopy. Electrical conductivity of the polymer and its doped samples were determined by the 4-probe technique. It was found that the electrical conductivity increased up to 10-4 S/cm after doping. The redox behaviour of the polymer was investigated utilizing cyclic voltammetry.

Polypyrrole@α-Al2O3 and polypyrrole@CeO2 core-shell hybrid nanocomposites

2017 ◽  
Vol 52 (11) ◽  
pp. 1433-1441 ◽  
Author(s):  
AS Silva ◽  
SM de Souza ◽  
EA Sanches
Keyword(s):  
Electrical Conductivity ◽  
Differential Scanning Calorimetry ◽  
Diffraction Pattern ◽  
Hybrid Nanocomposites ◽  
Core Shell ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dc Electrical Conductivity

PPy@ α-Al2O3 and PPy@CeO2 nanocomposites were synthesized free of acids by in situ polymerization and characterized by X-ray diffraction, scanning electron microscopy, differential scanning calorimetry and DC electrical conductivity measurements. X-ray diffraction pattern of Polypyrrole revealed a semi crystalline structure. The Le Bail method was performed using the X-ray diffraction pattern of polypyrrole and allowed the proposition of the unit cell parameters (P21/c, a = 9.0173 Å, b = 7.1641 Å, c = 6.4184 Å, α = 90°, β = 117.7°, γ = 90°), which is composed by a dimeric molecule disposed along the [001] direction. A cauliflower-like morphology was observed in polypyrrole, which consists of incomplete spheres forming nanoparticle clusters. Core-shell morphology was verified in the nanocomposites consisting of a thin layer of polymer reinforcement disposed over the metal oxides matrices. Differential scanning calorimetry measurements allowed verifying the hydrophobic behavior of the inorganic phase, promoting the repulsion of the internal water molecules out from the polymer phase. Then the initial decomposition temperature of the nanocomposites has become smaller. The polypyrrole electrical conductivity is lower than the nanocomposites and may be related with the absence of hydration water in nanocomposites and also to the surface conductivity due to the thin polymer layer. PPy@ α-Al2O3 and PPy@CeO2 nanocomposites presented DC electrical conductivity 80% higher when compared to the as-synthesized polypyrrole. Thus, the aim of this paper was to characterize structural and morphologically the pure polypyrrole as well as the PPy@α-Al2O3 and PPy@CeO2 nanocomposites and correlate these results with the DC electrical conductivity measurements.

Thermoelectric Properties of Arc-Melted Ba8Al16Si30 Clathrate

2007 ◽  
Vol 539-543 ◽  
pp. 3309-3312 ◽  
Author(s):  
Jung Il Lee ◽  
Jong Bum Park ◽  
Sin Wook You ◽  
Joo Ho Lee ◽  
Young Ho Kim ◽  
...  
Keyword(s):  
Thermoelectric Properties ◽  
Density Measurement ◽  
Hardness Test ◽  
Homogenization Temperature ◽  
Vacuum Furnace ◽  
Type I ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Type Conduction

Ba8Al16Si30 type I clathrate was produced by arc melting and thermoelectric properties were investigated. The phase transformation behavior of arc-melted type I Ba8Al16Si30 was examined by thermogravimetric analysis, differential scanning calorimetry, hardness test, density measurement, X-ray diffraction and scanning electron microscope analyses. Homogenization was carried out to induce the transformation to a thermoelectric phase at 773K to 973K for 5 hours and 24 hours in the vacuum furnace. Thermoelectric properties in the temperature range between 300K and 600K were measured and evaluated. Electrical conductivity was decreased and Seebeck coefficient was increased with increasing homogenization temperature and time. The arc-melted and the homogenized specimens represented n-type conduction at temperatures examined, and they showed reliable thermoelectric behaviors with increasing homogenization temperature and time.

Study of Diffusion-Homogenization on SiCp/Al Composites Prepared by Elemental Powder

2011 ◽  
Vol 415-417 ◽  
pp. 410-414
Author(s):  
Yun Xia Liu ◽  
Yue Liu ◽  
Bao Yong Wang ◽  
Hui Xie ◽  
Si Da Liu
Keyword(s):  
Electron Microscopy ◽  
Hot Pressing ◽  
Homogenization Temperature ◽  
Processing Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Vacuum Hot Pressing ◽  
Sintering Method ◽  
Scanning Electron ◽  
Al Matrix

SiCp/Al composites were prepared by vacuum hot pressing and sintering method. Optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD) is applied to study the diffusion-homogenization process of various elements of powder, and the effect of the diffusion-homogenization temperature and holding time on the SiCp/Al Composites’ microstructure in state of vacuum hot pressing. The results show that the Enrichment of Cu-phase is existed in the composites organization which is in the state of vacuum hot pressing; Al2CuMg fully dissolve into the Al matrix, Cu fully diffused and the diffusion of various elements becomes homogeneous with the temperature increased and time extend. The best processing parameters for the diffusion-homogenization is at 500°Cfor 3h.

Effect of Homogenizing Treatment on Microstructure and Property of Al-Zn-Mg-Cu-Zr Aluminum Alloy

2016 ◽  
Vol 877 ◽  
pp. 587-592
Author(s):  
Gao Song Wang ◽  
Qing Qiang Chen ◽  
Kai Tao ◽  
Qi Chao Chen ◽  
Zhi Hao Zhao
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Electrical Conductivity ◽  
Homogenization Temperature ◽  
Ingot Metallurgy ◽  
X Ray Diffraction ◽  
Slow Cooling ◽  
X Ray ◽  
Processing Effects ◽  
Equilibrium Phases

A series of Al-6.3Zn-2.3Mg-2.3Cu-0.15Zr alloys with different reduce of Zn, Mg, Cu and Zr were prepared by ingot-metallurgy processing. Effects of homogenization on the microstructure and properties of Al-Zn-Mg-Cu-Zr aluminium alloy were respectively studied by means of metallographic microscopy, electrical conductivity test, differential thermal analysis and X-ray diffraction phase analysis. The results indicated that the overheating temperature of these alloys is between 473°C and 477°C, and there was little difference to the overheating temperature of 7050 alloy. During homogenization process, using three kinds of developed heat treatment of homogenization of 7050 alloy, with the rising of homogenization temperature and the complication of the homogenization heat treatment, the electrical conductivity decreased and hardness gradually increased. The three-step homogenization has a better effect than single homogenization, as it can completely eliminate the endothermic peak of non-equilibrium phases. Many MgZn2 phases are present in the ingot with three-step homogenization and slow cooling.

scholarly journals Observation of microstructure evolution during inertia friction welding using in-situ synchrotron X-ray diffraction

2021 ◽  
Vol 28 (3) ◽  
pp. 790-803
Author(s):  
Matthew Rowson ◽  
Chris J. Bennett ◽  
Mohammed A. Azeem ◽  
Oxana Magdysyuk ◽  
James Rouse ◽  
...  
Keyword(s):  
Microstructure Evolution ◽  
Friction Welding ◽  
Numerical Models ◽  
High Carbon Steel ◽  
Equilibrium Phase ◽  
Inertia Friction Welding ◽  
Contact Interface ◽  
X Ray Diffraction ◽  
X Ray

The widespread use and development of inertia friction welding is currently restricted by an incomplete understanding of the deformation mechanisms and microstructure evolution during the process. Understanding phase transformations and lattice strains during inertia friction welding is essential for the development of robust numerical models capable of determining optimized process parameters and reducing the requirement for costly experimental trials. A unique compact rig has been designed and used in-situ with a high-speed synchrotron X-ray diffraction instrument to investigate the microstructure evolution during inertia friction welding of a high-carbon steel (BS1407). At the contact interface, the transformation from ferrite to austenite was captured in great detail, allowing for analysis of the phase fractions during the process. Measurement of the thermal response of the weld reveals that the transformation to austenite occurs 230 °C below the equilibrium start temperature of 725 °C. It is concluded that the localization of large strains around the contact interface produced as the specimens deform assists this non-equilibrium phase transformation.

Sign in / Sign up

Export Citation Format

Share Document