scholarly journals Structural Changes in the Aluminum - Magnesium System Alloy

2020 ◽  
Vol 989 ◽  
pp. 577-582
Author(s):  
I.E. Illarionov ◽  
T.R. Gilmanshina ◽  
A.A. Kovaleva

The purpose of this work is to study the structure and mechanical properties of an aluminum – magnesium system alloy after various types of heat treatment (quenching and ageing). The microstructure of an alloy has been studied by means of Zeiss OBSERVER.D1m microscope combined with a camera and image display on a monitor screen. Micro X-ray spectral analysis was performed by means of Carl Zeiss EVO 50 scanning electron microscope. The micro-hardness of the samples has been measured on prepared metallographic sections by means of DM8 micro-hardness meter. In the course of the process it has been found that quenching the Al-12,78% Mg alloy from temperatures of 430–440 ° C does not lead to the formation of a single-phase solid solution. Ageing at 100 ° C enables the formation of secondary phases. It was noted that with an increase in the quenching temperature, the micro-hardness increases slightly. An increase in the exposure time doesn’t influence greatly the micro-hardness of the alloy, while the structure remains practically unchanged.

2018 ◽  
Vol 18 ◽  
pp. 73-78
Author(s):  
Mokhtar Bayarassou ◽  
Mosbah Zidani ◽  
Hichem Farh

The scope of this work is to study of microstructural changes and mechanical properties during natural and artificial ageing treatment of AGS Alloy wire cold drawn with different deformation at ENICAB in Biskra. And as well to know the phase formation during different deformation of aluminum alloys wires. as well as the combined influence of the plastic deformation rate and the aging temperature. Wire section reduction shows a change in microstructure and texture. The methods of characterization used in this work are: scanning electron microscope and X-ray diffraction, micro hardness (Hv).


2013 ◽  
Vol 686 ◽  
pp. 211-215
Author(s):  
Nadia Metidji ◽  
Nacer Eddine Bacha ◽  
Djamal Saidi ◽  
Slimane Boutarfaia

This work has been undertaken in order to determine the effect of alloying with Ni, Mo and B additions on physical and mechanical properties of FeAl alloys. The structural evolutions and morphological changes alloys were characterized by X. ray diffractometry (XRD), Scanning Electron Microscope (SEM) and an Optical Microscope. Antiphase domain sizes and morphologies are reported and correlations between such ordening phenomena, phase precipitations and mechanical properties (micro hardness at low temperature) are discussed.


2012 ◽  
Vol 620 ◽  
pp. 219-223 ◽  
Author(s):  
Mohd Fariz Ab Rahman ◽  
Julie Juliewatty Mohamed ◽  
Mohd Fadzil Ain ◽  
Sabar Derita Hutagalung

The properties of undoped and Mg-doped CaCu3Ti4O12 (CCTO) ceramics have been studied. The samples were calcined at 900°C for 12 hours, and sintered at 1030°C for 10 hours. X-ray diffraction analysis on calcined samples shown the formation of CCTO phase with trace of secondary phases meanwhile completed formation of CCTO single phase obtained for sintered pellets. The peak positions of Mg-doped CCTO were slightly left-shifted from the undoped CCTO, attributed to the lattice expansion. Scanning electron microscopy analysis showed that the grains size becomes larger with the increment of dopant amount. Enhanced dielectric constant was observed in the Ca1-xMgxCu3Ti4O12 ceramics with x = 0.05 for the frequency range from 1 MHz to 1 GHz. The dielectric loss seem to be at lowest value when Ca1-xMgxCu3Ti4O12 ceramics with x = 0.10 at the same frequency range. The results indicate that Mg ions have effectively changed the properties of CCTO.


The effects of substitution of Fe in the boron-rich Fe–B–C alloys, containing 10.0–14.0 % B; 0.1–1.2 % C; Fe – the remainder, 5.0 % Ti, Al, or Si (in wt. %) have been studied with optical microscopy, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy. Mechanical properties, such as microhardness and fracture toughness, have been measured by Vickers indenter. The microstructure of the master Fe–B–C alloys cooled at 10 and 103 K/s consists of primary dendrites of Fe(B,C) solid solution and Fe2(B,C) crystals. It has been found that titanium has the lowest solubility in the constituent phases of the Fe–B–C alloys, with preferential solubility observed in the Fe(B,C) dendrites, where Ti occupies Fe positions. This element has been shown to be mainly present in secondary phases identified as TiC precipitates at the Fe2(B,C) boundaries. Titanium slightly enhances microhardness and lowers fracture toughness of the boron-rich Fe–B–C alloys due to substitutional strengthening of Fe(B,C) dendrites and precipitation of the secondary phases. The level of the content of Al or Si in the Fe(B,C) and Fe2(B,C) solid solutions and quantity of the secondary phases observed in the structure suggest that more Al or Si are left in the constituent phases as compared with Ti. These elements mainly enter the crystal lattice of Fe2(B,C) phase replacing iron atoms and form at their boundaries AlB12C and SiC compounds respectively. The additions of Al and Si to the boron-rich Fe–B–C alloys help to modify their fragility: while they slightly decrease microhardness values, addition of these elements improves the fracture toughness of the constituent phases. Increase in a cooling rate from 10 to 103 K/s does not bring about any noticeable changes in the solubility behavior of the investigated alloying elements. The rapid cooling gives rise to microhardness and fracture toughness of the phase constituents which average sizes significantly decrease. The effects of the alloying elements on the structure and mechanical properties of the investigated boron-rich Fe–B–C alloys have been explained considering differences in the atomic radii and electronic structure of the solute Ti, Al, or Si atoms.


2014 ◽  
Vol 59 (4) ◽  
pp. 1351-1354 ◽  
Author(s):  
G. Golanski ◽  
A. Zielinski ◽  
J. Słania ◽  
J. Jasak

Abstract The paper describes the influence of different times of ageing on mechanical properties and microstructure stability in hardened and tempered VM12 steel exposed to service temperature - 600°C. Detailed microstructural and microchemical analysis of secondary phases was carried out using scanning electron microscopy (SEM + EDX) and X-ray phase analysis of carbide isolates. Performed research has proved high stability of strength properties of the investigated steel, which is connected with the lath stability of the microstructure of tempered martensite. Slight changes in strength properties were accompanied by over 50% reduction in impact strength KV of the examined cast steel, from the level of 83 J in the as-received condition to 38 J after 30 000 hrs of ageing at the temperature of 600°C. Significant decrease in impact energy KV of VM12 steel results from the growth of the amount and size of precipitations on grain boundaries.


2012 ◽  
Vol 525-526 ◽  
pp. 277-280
Author(s):  
Guo Jin ◽  
Xiu Fang Cui ◽  
Er Bao Liu ◽  
Qing Fen Li

The effect of the neodymium content on mechanical properties of the electro-brush plated nanoAl2O3/Ni composite coating was investigated in this paper. The microstructure and phase structure were studied with scanning electron microscope (SEM) and X-ray diffraction (XRD). The hardness and abrasion properties of several coatings with different neodymium content were studied by nanoindentation test and friction / wear experiment. Results show that the coatings are much finer and more compact when the neodymium was added, and the hardness and abrasion property of the coatings with neodymium were improved obviously. Besides, the small cracks conduced by the upgrowth stress in the coatings were ameliorated when the rare earth neodymium was added. The improvement mechanism was further discussed.


2012 ◽  
Vol 476-478 ◽  
pp. 1031-1035
Author(s):  
Wei Min Liu ◽  
Xing Ai ◽  
Jun Zhao ◽  
Yong Hui Zhou

Al2O3-TiC-ZrO2ceramic composites (ATZ) were fabricated by hot-pressed sintering. The phases and microstructure of the composites were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The relative density and mechanical properties (flexural strength, fracture toughness and Vicker’s hardness) of the composites were tested. The results show that the microstructure of the composites was the gray core-white rim. With the increase of sintering temperature, the relative density and mechanical properties of the composites increased first and then decreased. The composite sintered at 1705°C has the highest synthetical properties, and its relative density, flexural strength, fracture toughness and Vickers hardness are 98.3%,970MPa,6.0 MPa•m1/2and 20.5GPa, respectively.


2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.


2021 ◽  
Vol 66 (1) ◽  
pp. 57-64
Author(s):  
Hang Pham Vu Bich ◽  
Yen Nguyen Hai ◽  
Mai Phung Thi Thanh ◽  
Dung Dang Duc ◽  
Hung Nguyen Manh ◽  
...  

In this study, we present the process of synthesis FexNi1-xMn2O4 (x = 0; 0.1; 0.3; 0.5; 0.7; 0.9; 1) by method sol-gel. Scanning electron microscope results shows that the particle size is about 50 nm. The X-ray diffraction diagram shows that the samples are single phase, changing structure clearly as the x ratio increases from 0 to 1. The lattice constant, the bond length also changes with x-value as shown on the Raman scattering spectrum. The results of the vibrating sample magnetometer show that the magnetism of the material FexNi1-xMn2O4 changes with the value of x and reaches a maximum in the range x from 0.5 to 0.7.


1989 ◽  
Vol 169 ◽  
Author(s):  
Winnie Wong‐Ng ◽  
Lawrence P. Cook ◽  
Michael D. Hill ◽  
Boris Paretzkin ◽  
E.R. Fuller

AbstractThe influence of the ionic size of the lanthanides R on melting relations of Ba2RCu3O6+x, where R=Y, Eu and Nd, was studied and compared with that of a high Tc superconductor mixed‐lanthanide phase Ba2(Y.75Eu.125Nd 125)Cu3O6+xThese materials have been characterized by a variety of methods including differential thermogravimetric analysis (DTA), scanning electron microscopy (SEM) with energy dispersive X‐ray spectroscopy (EDX) and X‐ray powder diffraction. Single phase samples of Ba2(Y.75Eu.125Nd.125)Cu3O6+x were annealed at 1004, 1040, 1052, 1060, 1078, 1107 and 1160°C and quenched into a helium gas container cooled by liquid nitrogen. The SEM micrographs of these samples showed the progressive chnages in features of the microstructures from sintering and grain growth through melting and then recrystallization from the melt. The addition of the SEM technique in conjunction with X‐ray diffraction has been helpful in the study of phase equilibria in this system.


Sign in / Sign up

Export Citation Format

Share Document