scholarly journals Effect of Thermomechanical Treatment of Al-Zn-Mg-Cu with Minor Amount of Sc and Zr on the Mechanical Properties

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 589
Author(s):  
Azam Beigi Kheradmand ◽  
Shamseddin Mirdamadi ◽  
Zahra Lalegani ◽  
Bejan Hamawandi
Keyword(s):  
Thermomechanical Treatment ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Minor Amount ◽  
Precipitate Morphology ◽  
Software Analysis ◽  
Heat Treated ◽  
The Matrix ◽  
Mechanical And Microstructural Properties

In this study, the mechanical and microstructural properties of Al-Zn-Mg-Cu-Zr cast alloy with 0.1% Sc under homogeneous, dissolution, and T6 and thermomechanical treatments with the aim of increasing the volume fraction of MgZn2. Al3(Sc,Zr) reinforcing precipitates were examined by hardness, microscopic examinations, tensile tests and software analysis. The results showed that, firstly, the hardness results are well proportional to the results of the tensile properties of alloys and, secondly, the strength of the alloy with thermomechanical treatments compared to T6 treatments increased from 492 MPa to 620 MPa and the elongation increased from 8% to 17% and was 100% upgraded. Microstructural and fracture cross section investigations showed that Al3(Sc,Zr) nanosize dispersoids were evenly distributed among MgZn2 dispersoids and the alloy fracture was of semi-ductile type and nanosize dispersoids less than 10 nm were observed at the end of the dimples in the fracture section. The volume fraction of nanosize dispersoids in the whole microstructure of thermomechanical treatment samples was also much higher than that of T6 heat treated samples, so that the percentage of Al3(Sc,Zr) precipitates arrived from less than 1% in T6 operation to 8.28% in the quench-controlled thermomechanical operation (with 50% deformation). The quality index (QI) in thermomechanical treatment samples is 19% higher than T6 samples, so that this index has increased from 641 in T6 operation to 760 in samples under thermomechanical treatment due to precipitate morphology, volume fraction of precipitates, their uniform distribution in the matrix, and nano sized precipitates in samples under thermomechanical treatment.

scholarly journals Effect of Minor Amount of Sc on the Thermomechanical Treatment of Al-Zn-Mg-Cu-Zr Alloy

2021 ◽  
Author(s):  
Azam Beigi Kheradmand ◽  
Shamseddin Mirdamadi ◽  
Zahra Lalegani
Keyword(s):  
Thermomechanical Treatment ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Minor Amount ◽  
Microstructural Investigation ◽  
Software Analysis ◽  
Heat Treated ◽  
The Matrix ◽  
Mechanical And Microstructural Properties

Abstract In this study, mechanical and microstructural properties of Al-Zn-Mg-Cu-Zr cast alloy with 0.1% Sc under homogeneous, dissolution, and T6 and thermomechanical treatments with the aim of increasing the volume fraction of MgZn2 and Al3(Sc,Zr) reinforcing sediments were examined by hardness, microscopic examinations and tensile tests and software analysis. The results showed that firstly, the hardness results are well proportional to the results of tensile properties of alloys and secondly, the strength of the alloy with thermomechanical treatments compared to T6 treatments increased from 492 MPa to 620 MPa and the elongation increased from 8% to 17% and 100 % upgraded. Microstructural investigation and fracture cross section showed that Al3(Sc,Zr) nanoparticles were evenly distributed among MgZn2 particles and the alloy fracture was of semi-ductile type and in the fracture section nanoparticles less than 10 nm were observed at the end of the dimples. Also, the volume fraction of nanoparticles in the whole microstructure of thermomechanical treatment samples was much higher than that of T6 heat treated samples, so that the percentage of Al3(Sc,Zr) sediments from less than 1% in T6 operation to 8.28% in quench-controlled thermomechanical operation (with 50% deformation) has arrived. QI index in thermomechanical treatment samples is 19% higher than T6 samples, so that this index has increased from 641 in T6 operation to 760 in samples under thermomechanical treatment due to sediment morphology, volume fraction of sediments, their uniform distribution in the matrix, and nano sized sediments in samples under thermomechanical treatment.

scholarly journals Effect of thermomechanical treatment of Al-Zn-Mg-Cu with minor amount Sc and Zr on the mechanical properties

2021 ◽  
Author(s):  
Azam Beigi Kheradmand ◽  
Shamseddin Mirdamadi ◽  
Zahra Lalegani ◽  
Bejan Hamawandi
Keyword(s):  
Thermomechanical Treatment ◽  
Volume Fraction ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Minor Amount ◽  
Microstructural Investigation ◽  
Software Analysis ◽  
Heat Treated ◽  
The Matrix ◽  
Mechanical And Microstructural Properties

Abstract In this study, mechanical and microstructural properties of Al-Zn-Mg-Cu-Zr cast alloy with 0.1% Sc under homogeneous, dissolution, and T6 and thermomechanical treatments with the aim of increasing the volume fraction of MgZn2 and Al3(Sc,Zr) reinforcing sediments were examined by hardness, microscopic examinations and tensile tests and software analysis. The results showed that firstly, the hardness results are well proportional to the results of tensile properties of alloys and secondly, the strength of the alloy with thermomechanical treatments compared to T6 treatments increased from 492 MPa to 620 MPa and the elongation increased from 8% to 17% and 100 % upgraded. Microstructural investigation and fracture cross section showed that Al3(Sc,Zr) nanoparticles were evenly distributed among MgZn2 particles and the alloy fracture was of semi-ductile type and in the fracture section nanoparticles less than 10 nm were observed at the end of the dimples. Also, the volume fraction of nanoparticles in the whole microstructure of thermomechanical treatment samples was much higher than that of T6 heat treated samples, so that the percentage of Al3(Sc,Zr) sediments from less than 1% in T6 operation to 8.28% in quench-controlled thermomechanical operation (with 50% deformation) has arrived. QI index in thermomechanical treatment samples is 19% higher than T6 samples, so that this index has increased from 641 in T6 operation to 760 in samples under thermomechanical treatment due to sediment morphology, volume fraction of sediments, their uniform distribution in the matrix, and nano sized sediments in samples under thermomechanical treatment.

Strain Rate Effects on Tensile Properties of Fiber Reinforced Concrete

1985 ◽  
Vol 64 ◽  
Author(s):  
George G. Nammur ◽  
Antoine E. Naaman
Keyword(s):  
Reinforced Concrete ◽  
Strain Rate ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Strain Rate Effects ◽  
Rate Effects ◽  
The Matrix

ABSTRACTHigh strain rates lead to substantial modifications in the stress-strain (or stress-displacement) response of fiber reinforced concrete in tension. These modifications include higher strength and corresponding strain, as well as smaller displacement at failure.The purpose of this paper is to investigate the behavior of fiber reinforced concrete under impact tensile loading, and to study the effect of strain rate on the post-cracking strength of the composite. The variation of the tensile strength of the matrix with the reinforcement parameters such as volume fraction Vf and aspect ratio |/φ of the fibers is also studied ip this paper. A special emphasis is placed on the stress-displacement relationship of steel fiber reinforced concrete in its post-cracking range. An empirical model of the stress- displacement relationship as a function of the strain rate is developed from experimental data from tensile tests on dogbone shape notched tensile prisms. The model highlights the effects of strain rate and fiber properties on the post-cracking strength of the composite, as well as the displacement at failure. The effect of strain rate on the post-cracking toughness of fiber reinforced concrete is also addressed. The literature on impact effects on concrete in tension (plain and fiber reinforced) is briefly reviewed in this paper, and so is the state of the art of testing techniques for strain rate effects.

Microstructural Characterisation by Scanning Electron Microscopy of Spray Formed Al/SiCp Matrix Composite

2005 ◽  
Vol 498-499 ◽  
pp. 251-257 ◽  
Author(s):  
E.G. Gomes ◽  
J.L. Rossi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Volume Fraction ◽  
Spray Forming ◽  
Heat Treated ◽  
The Matrix ◽  
Microstructural Characterisation ◽  
Silicon Carbide Particles ◽  
Carbide Particles ◽  
Scanning Electron

The material used in this work was produced by spray forming AA7475 aluminium alloy and co-depositing silicon carbide particles (20% volume fraction). The spray formed composite billets were hot extruded into round bars. The microstructure was examined in the as received and heat treated (annealed, aged, and overaged) conditions by scanning electron microscopy. Scanning electron microscopy revealed an extensive Mg2Si phase precipitation at the Al/SiCp interface due probably to Mg segregation from the matrix to the interface, during the heat treatments.

Micromechanical theory and uniaxial tensile tests of fiber reinforced cement composites

1991 ◽  
Vol 6 (11) ◽  
pp. 2463-2473 ◽  
Author(s):  
C.C. Yang ◽  
T. Mura ◽  
S.P. Shah
Keyword(s):  
Volume Fraction ◽  
Tensile Tests ◽  
Uniaxial Tensile ◽  
Cement Composites ◽  
Matrix Composites ◽  
Fiber Reinforced ◽  
Theoretical Predictions ◽  
The Matrix ◽  
Reinforced Cement ◽  
Fracture Arrest

The mechanism of fracture arrest in brittle-matrix composites with strong, long fibers is analyzed by using the inclusion method. The maximum stress contribution of the matrix in composites is discussed in this paper. A critical volume fraction of fibers fc is theoretically derived. If the volume fraction f is less than fc, then debonding between fibers and matrix occurs before the crack propagates through the whole section. If f is greater than fc, then no debonding occurs before the crack propagates through the whole section. The value of fc depends on the matrix and fiber properties and the bond character of the interface. To verify the analytical predictions, experiments on fiber reinforced cement composites subjected to uniaxial tension were conducted. The results of the theoretical predictions were also compared satisfactorily with other published experimental data.

Optimized Thermomechanical Treatment for Strong and Ductile Martensitic Steels

2007 ◽  
Vol 539-543 ◽  
pp. 4526-4531 ◽  
Author(s):  
Araz Ardehali Barani ◽  
Dirk Ponge
Keyword(s):  
Heat Treatment ◽  
Thermomechanical Treatment ◽  
Spring Steel ◽  
Martensitic Steels ◽  
Medium Carbon ◽  
Heat Treated ◽  
Conventional Heat Treatment ◽  
The Matrix ◽  
Different Levels ◽  
Strength And Ductility

In this study the effect of thermomechanical treatment on the microstructure of austenite and martensite and the mechanical properties of a medium carbon silicon chromium spring steel with different levels of impurities is investigated. Results are presented for conventional heat treatment and for thermomechanical treatment (TMT). Compared to conventionally heat treated samples austenite deformation improves strength and ductility. Thermomechanically treated samples are not prone to embrittlement by phosphorous. TMT influences the shape and distribution of carbides within the matrix and at prior austenite grain boundaries. It is shown that utilization of TMT is beneficial for increasing the ultimate tensile strength to levels above 2200 MPa and at the same time maintaining the ductility obtained at strength levels of 1500 MPa by conventional heat treatment. The endurance limit is increased and embrittlement does not occur.

Microstructure Characterization and Mechanical Properties of a Zn and Rare Earth Modified Mg Alloy

2015 ◽  
Vol 727-728 ◽  
pp. 111-114 ◽  
Author(s):  
Li Yuan Sheng ◽  
Fang Yang ◽  
Ting Fei Xi
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Hot Extrusion ◽  
Eutectic Structure ◽  
Crystal Defects ◽  
Treatment Results ◽  
Nanoscale Particles ◽  
Residual Phase ◽  
Heat Treated ◽  
The Matrix

In the present paper, the Mg-Zn-Y-Nd alloy is fabricated by as casting and hot extrusion. Microstructure and mechanical properties of the as-cast, heat treated and hot extruded alloys are investigated. The results exhibit that Mg24Y5 phase with eutectic structure forms in the as-cast alloy, which has an orientation relationship with matrix of . The precipitating phase separates the matrix semi-continuously. The heat treatment results in most precipitates solid soluted into matrix, but there are still some nanoscale particles and residual phase along grain boundary. The hot extrusion refines the microstructure and leads to the formation of stacking faults in the matrix. Compared with the as-cast and heat treated alloy, the hot extruded alloy obtain great improvement in mechanical properties, which should be attributed to the grain refinement, solid solution and fomation of crystal defects

Synthesis, Microstructure, and Mechanical Properties of FeCo-VC Composites

2006 ◽  
Vol 980 ◽  
Author(s):  
Hongbin Bei ◽  
E. P. George
Keyword(s):  
Mechanical Properties ◽  
Cast Alloy ◽  
Tensile Tests ◽  
Eutectic Structure ◽  
Directionally Solidified ◽  
Quaternary Alloys ◽  
The Matrix ◽  
Solid Solution Matrix ◽  
Solution Matrix

AbstractFe-Co-V-C quaternary alloys were drop cast and directionally solidified to obtain an in situ composite. It is found that the fully eutectic structure occurs at a composition of Fe - 40.5Co -10.4V- 8.6C (at. %) in a drop-cast alloy. Directional solidification of this composition in a high-temperature optical floating zone furnace produces a well-aligned microstructure, consisting of sub-micron VC fibers (~19% by volume) embedded in a FeCo-5V solid solution matrix containing ~ 1% C. The temperature dependencies of mechanical properties of this composite were examined by tensile tests and the composite was found to have higher yield strength and lower ductility than the matrix.

Fracture Analysis and Mechanical Properties of Magnesium Based Composites

2017 ◽  
Vol 891 ◽  
pp. 526-532 ◽  
Author(s):  
Beáta Ballóková ◽  
Dagmar Jakubéczyová
Keyword(s):  
Mechanical Properties ◽  
Volume Fraction ◽  
Tensile Tests ◽  
Fracture Analysis ◽  
Physical Parameters ◽  
Weight Percentage ◽  
Matrix Microstructure ◽  
Angular Pressing ◽  
The Matrix ◽  
Average Size

Mechanical properties and microstructure and fracture analysis of a magnesium alloys based composite series with different volume fraction of alumina dispersoid nanoparticles were studied. The initial states of the composites were further treated by severe plastic deformation (SPD) using equal channel angular pressing (ECAP) in order to achieve microstructures with very fine grains of matrix. Microstructure parameters, in particular the matrix grain size, average size of the dispersed particles and their distribution, were observed using optical microscopy. The average grain sizes of MMCs decreased evidently with the increase of the weight percentage of Al2O3 particles additions and ECAP passes. The heat deformation process of such materials, besides the formation of incorporated Al2O3 particles, also leads to the creation of intermetallic compound Mg17Al12. Fracture surfaces after tensile tests at room and elevated temperature were studied by SEM. The fracture of studying materials were characterized as the ductile fracture due to the existence of a large number of dimples.In summary, it has been shown that mechanical properties are affected by lattice, physical parameters of phases within the composite systems. They are also affected by microstructure and substructure, which depend on the technology of compaction and densification.

scholarly journals Hybrid Composites of Polylactide with Basalt and Carbon Fibers and Their Thermal Treatment

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 95 ◽  
Author(s):  
Stanisław Kuciel ◽  
Paulina Romańska
Keyword(s):  
Water Absorption ◽  
Elevated Temperatures ◽  
Hybrid Composites ◽  
Tensile Tests ◽  
Equal Mass ◽  
Degree Of Crystallinity ◽  
Stress Concentrations ◽  
Scanning Calorimetry ◽  
Heat Treated ◽  
The Matrix

In this research, polylactide was hybrid-reinforced and heat-treated in order to obtain durable structural materials with the use of eco-friendly components. Differential scanning calorimetry (DSC) analysis, tensile tests at various temperatures, Vicat tests, impact tests, and microscopic observations were conducted on the annealed and non-heat-treated specimens. The theoretical and true density, as well as water absorption, were also determined. The simultaneous introduction of chopped carbon and basalt fibers in equal mass fractions of 7.5% and 12.5% resulted in satisfactory increases in stiffness and tensile strength. The reinforcing effect was more efficient for the heat-treated composites, especially at elevated temperatures. Heat treatment significantly increased the degree of crystallinity of the matrix, improving heat resistance and reducing water absorption. It also reduced the stress concentrations in the injection-molded specimens.

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