scholarly journals Effect of Bimodal Grain Structure on the Microstructural and Mechanical Evolution of Al-Mg/CNTs Composite

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1524
Author(s):  
Behzad Sadeghi ◽  
Pasquale Cavaliere
Keyword(s):  
Uniform Elongation ◽  
Hot Extrusion ◽  
High Strength ◽  
Grain Structure ◽  
Alloy Structure ◽  
Influence Zone ◽  
Al2o3 Layer ◽  
Mechanical Evolution ◽  
The Matrix ◽  
Spinel Mgal2o4

The Al-Mg alloy structure reinforced with carbon nanotubes was evaluated after the composites production through a modified flake metallurgy technique followed by hot extrusion. The obtained bimodal microstructure of the matrix allowed to identify the microstructural mechanisms leading to high strength; uniform elongation and strain hardening ability of the produced composites. The presence of Mg transformed the native Al2O3 layer into spinel MgAl2O4 nano-phases dispersed both inside CG and UFGs and on the interfaces, improving the interfacial bonding of Al-Al as well as Al-CNT. The effect of the reinforcing phases percentages on the dislocations mechanisms evolution was evaluated through stress relaxation tests leading to the underlying of the effect of reinforcing phases on the modification of the interphase influence zone

scholarly journals The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

2014 ◽  
Vol 14 (2) ◽  
pp. 57-62
Author(s):  
M. Szymaneka ◽  
B. Augustyn ◽  
D. Kapinos ◽  
S. Boczkal ◽  
J. Nowak
Keyword(s):  
Rapid Solidification ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
High Strength ◽  
Strength Properties ◽  
Grain Structure ◽  
Ultrafine Grain ◽  
Plastic Working ◽  
Metal Treatment ◽  
Ultrafine Grain Structure

Abstract In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength properties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the properties. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt spinning device is an intermediate product for further plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon of an ultrafine grain or nanometric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attention on the technological aspect of the above mentioned process and described successive stages of the fabrication of an AlZn9Mg2.5Cu1.8 alloy of ultrafine grain structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the article were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casting by RS and subsequent fragmentation.

scholarly journals Fabricate of High-Strength and High-Conductivity Cu–Cr–Si Alloys through ECAP-Bc and Aging Heat Treatment

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1603 ◽  
Author(s):  
Tingbiao Guo ◽  
Junjie Wang ◽  
Yibo Wu ◽  
Xiaoyang Tai ◽  
Zhi Jia ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electron Backscatter Diffraction ◽  
Aging Treatment ◽  
High Strength ◽  
High Conductivity ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Angular Pressing ◽  
The Matrix ◽  
Backscatter Diffraction

The effect of equal channel angular pressing (ECAP) through the route Bc and aging treatment on the grain structure and properties of the Cu–1Cr–0.2Si alloy was investigated. Microstructure was detected by scanning electron microscopy (SEM), x-ray diffraction (XRD), and electron backscatter diffraction (EBSD) and the mechanical properties and electrical conductivity were tested. Results shown that after ECAP, accompanying the grains refined to nano-and submicron-structure, the Cr particles were gradually spread along the grain boundaries (GBs), aging treatment promoted Cr particles dispersed in the matrix. ECAP greatly increased the ultimate tensile strength (UTS) while having a small effect on the conductivity, and aging treatment increased electrical conductivity. The stable {111}<110> texture after ECAP and the lower dislocation density after aging treatment maybe the main reasons for the high conductivity of the material.

Fabrication and Properties of High Strength Al-8Fe-2Mo-2V-1Zr Alloy Produced by Melt Spinning Techniques

2006 ◽  
Vol 510-511 ◽  
pp. 854-857 ◽  
Author(s):  
Taek Kyun Jung ◽  
Dong Suk Lee ◽  
Mok Soon Kim ◽  
Won Yong Kim
Keyword(s):  
Particle Size ◽  
Yield Strength ◽  
Melt Spinning ◽  
Room Temperature ◽  
Intermetallic Phase ◽  
Hot Extrusion ◽  
High Strength ◽  
Extrusion Temperature ◽  
Grain Structure ◽  
Melt Spun

High strength Al-8Fe-2Mo-2V-1Zr (wt.%) alloys fabricated by a melt spinning and a hot extrusion process were produced to correlate the microstructure and mechanical property. Melt spun ribbon prepared by single roll melt spinner showed a cellular structure with an average size of 10nm and Al-Fe based intermetallic dispersoid of less than 10nm in particle size. The melt spun ribbon obtained was then pulverized to make a powder shape followed by hot extrusion at 648K, 673K, 723K and 773K in extrusion ratio of 5 to 1, respectively. Equiaxed grain structure containing Al-Fe based intermetallic phase was observed in all extruded specimens. According to increasing extrusion temperature, the grain size increased and particle size of intermetallic dispersoid. The lattice parameter increased from 0.4051nm to 0.4059 nm with increasing extrusion temperature from 648K to 773K, those values were larger than that obtained in pure Al (0.4049nm). Yield strength of the specimen extruded at 648K measured to 956MPa at room temperature, 501MPa at 573K and 83MPa at 773K, respectively. With increasing extrusion temperature yield strength decreased significantly at room temperature and even in the intermediate temperature range, while no noticeable difference in yield strength was observed at 773K.

Microstructure and Mechanical Properties of Extruded Mg-Zn-Y Alloy

2013 ◽  
Vol 747-748 ◽  
pp. 443-448
Author(s):  
Feng Wang ◽  
Ji Bao Li ◽  
Ping Li Mao ◽  
Zheng Liu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Yield Strength ◽  
Hot Extrusion ◽  
High Strength ◽  
Energy Dispersive Spectrum ◽  
Ageing Treatment ◽  
Coarse Dendrite ◽  
Average Grain Size ◽  
The Matrix

A high strength and toughness extruded Mg-Zn-Y alloy based on quasicrystal-strengthening has been studied. The effect of extrusion and heat treatment on the microstructures and mechanical properties of Mg-Zn-Y alloy were studied by optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive spectrum (EDS), X-ray diffraction (XRD) and tensile testing. The experimental results indicated that the coarse dendrite crystals were broken through the hot extrusion, and dynamic recrystallization appeared during the hot extrusion, which obviously refined the hot-extruded microstructure to the average grain size about 20μm. A large amount of strengthening phases such as Mg3Zn6Y(I-Phase), Mg12ZnY(X-Phase) and MgZn2, which were massive, grainy and clavate, dispersedly precipitated from the matrix along grain boundary during ageing treatment at 225 after extrusion, and made the sliding of grain boundaries restrained, which resulted in an enhancement for mechanical properties to a great extent. At the same time, the tensile strength and yield strength increased after ageing treatment. After ageing treatment of 225×24h, the highest tensile strength and yield strength of the extruded Mg-Zn-Y alloy were obtained: σb=506.7MPa, σ0.2=373.5MPa, which were increased by 104.8% and 120.4%, respectively, compared with the extruded Mg-Zn-Y alloy, however the elongation decreased to 16.52%.

scholarly journals Improving Mechanical Properties of Mg–Sc Alloy by Surface AZ31 Layer

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2021
Author(s):  
Cheng Zhang ◽  
Cheng Peng ◽  
Jin Huang ◽  
Yanchun Zhao ◽  
Tingzhuang Han ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hot Extrusion ◽  
Grain Structure ◽  
Gradient Structure ◽  
Alloy Structure ◽  
Fine Grain ◽  
Fine Grain Strengthening ◽  
Gradient Microstructure ◽  
Solution Strengthening ◽  
Dislocation Strengthening

Building a gradient structure inside the Mg alloy structure can be expected to greatly improve its comprehensive mechanical properties. In this study, AZ31/Mg–Sc laminated composites with gradient grain structure were prepared by hot extrusion. The microstructure and mechanical properties of the Mg–1Sc alloy with different extrusion temperatures and surface AZ31 fine-grain layers were investigated. The alloy has a more obvious gradient microstructure when extruded at 350 °C. The nanoscale hardness value of Mg–1Sc alloy was improved through fine-grain strengthening and solution strengthening of the surface AZ31 fine-grain layer. The strength of Mg–1Sc alloy was improved due to the fine-grain strengthening and dislocation strengthening of the surface AZ31 fine-grain layer, and the elongation of Mg–1Sc alloy was increased by improving the distribution of the microstructure.

Al-5Cu Alloy Processed by Equal-Channel Angular Pressing

2016 ◽  
Vol 879 ◽  
pp. 843-848 ◽  
Author(s):  
Hai Long Jia ◽  
Knut Marthinsen ◽  
Yan Jun Li
Keyword(s):  
Equal Channel Angular Pressing ◽  
Electron Backscatter Diffraction ◽  
Uniform Elongation ◽  
Rate Sensitivity ◽  
High Strength ◽  
Secondary Phase ◽  
Grain Structure ◽  
Ultrafine Grains ◽  
Cu Content ◽  
Angular Pressing

An ECAP (equal channel angular pressing) processed UFG Al-5Cu alloy was characterized by electron backscatter diffraction (EBSD). It is revealed that a bimodal grain structure, i.e. ultrafine grains accompanied by micron-sized grains was developed after 4 passes. A high strength (~501 MPa) and a relatively large elongation to failure (~28%) with ~5% uniform elongation were achieved simultaneously after 4 passes of ECAP. The high strength is due to a combination of strengthening by solute, high density of dislocations and ultrafine grains. The enhancement of uniform elongation is primarily due to the enhanced work hardening resulted from the solute Cu content and the bimodal grain structure. The large post-uniform elongation is attributed to the high strain rate sensitivity of the UFG Al-5Cu alloy. More importantly, the present work revealed that during ECAP high solid solution content of Cu and coarse secondary phase particles can introduce inhomogeneous deformation resulting in a desirable bimodal grain structure, which can be utilized as a strategy to gain both high strength and relatively good ductility.

FORMALOY

Alloy Digest ◽  
1975 ◽  
Vol 24 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Corrosion Resistance ◽  
Sheet Metal ◽  
High Purity ◽  
Base Alloy ◽  
High Strength ◽  
Heat Treating ◽  
Grain Structure ◽  
Excellent Performance

Abstract FORMALOY is a high-strength, high-purity zinc-base alloy with excellent performance in dies for forming sheet metal. It has a fine, dense grain structure which contributes markedly to its good toughness, excellent machinability and ability to develop a high polish. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and compressive strength as well as fracture toughness. It also includes information on corrosion resistance as well as casting, forming, heat treating, machining, and joining. Filing Code: Zn-17. Producer or source: Federated Metals Corporation, ASARCO Inc..

Grain Refinement and Deformation Behavior of Ultrafine Grained Pd and Pd-Ag Alloys Produced by HPT

2008 ◽  
Vol 584-586 ◽  
pp. 182-187
Author(s):  
Lilia Kurmanaeva ◽  
Yulia Ivanisenko ◽  
J. Markmann ◽  
Ruslan Valiev ◽  
Hans Jorg Fecht
Keyword(s):  
Mechanical Properties ◽  
Deformation Behavior ◽  
Materials Science ◽  
High Pressure Torsion ◽  
Uniform Elongation ◽  
Grain Structure ◽  
Coarse Grained ◽  
Ultrafine Grain ◽  
Ultrafine Grained ◽  
Ultrafine Grain Structure

Investigations of mechanical properties of nanocrystalline (nc) materials are still in interest of materials science, because they offer wide application as structural materials thanks to their outstanding mechanical properties. NC materials demonstrate superior hardness and strength as compared with their coarse grained counterparts, but very often they possess a limited ductility or show low uniform elongation due to poor strain hardening ability. Here, we present the results of investigation of the microstructure and mechanical properties of nc Pd and Pd-x%Ag (x=20, 60) alloys. The initially coarse grained Pd-x% Ag samples were processed by high pressure torsion, which resulted in formation of homogenous ultrafine grain structure. The increase of Ag contents led to the decrease of the resulted grain size and change in deformation behavior, because of decreasing of stacking fault energy (SFE). The samples with larger Ag contents demonstrated the higher values of hardness, yield stress and ultimate stress. Remarkably the uniform elongation had also increased with increase of strength.

Investigation of Fiber-Reinforced Modified Epoxy Resin Composites

2012 ◽  
Vol 510-511 ◽  
pp. 577-584 ◽  
Author(s):  
A. Quddos ◽  
Mohammad Bilal Khan ◽  
R.N. Khan ◽  
M.K.K. Ghauri
Keyword(s):  
Epoxy Resin ◽  
High Strength ◽  
Polymeric Matrix ◽  
Fiber Reinforced Composites ◽  
Resin Matrix ◽  
Reinforced Composites ◽  
Fiber Reinforced ◽  
Epoxy Resin Matrix ◽  
The Matrix ◽  
Modified Epoxy

The impregnation of the fiber with a resin system, the polymeric matrix with the interface needs to be properly cured so that the dimensional stability of the matrix and the composite is ensured. A modified epoxy resin matrix was obtained with a reactive toughening agent and anhydride as a curing agent. The mechanical properties of the modified epoxy matrix and its fiber reinforced composites were investigated systematically. The polymeric matrix possessed many good properties, including high strength, high elongation at break, low viscosity, long pot life at room temperature, and good water resistance. The special attentions are given to the matrix due to its low out gassing, low water absorption and radiation resistance. In addition, the fiber-reinforced composites showed a high strength conversion ratio of the fiber and good fatigue resistance. The dynamic and static of the composite material were studied by thermo gravimetric analysis (TGA), Differential Scanning Calorimetry (DSC) and Scanning Electron Microscopy (SEM) with EDX. The influences of processing technique such as curing and proper mixing on the mechanical and interfacial properties were determined. The results demonstrated that the modified epoxy resin matrix is very suitable for applications in products fabricated with fiber-reinforced composites.

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