Nanomaterials Applications in Modern Metallurgical Processes

2016 ◽  
Vol 9 ◽  
pp. 30-41 ◽  
Author(s):  
Konstantin Borodianskiy ◽  
Michael Zinigrad
Keyword(s):  
Mechanical Properties ◽  
Combined Treatment ◽  
A356 Alloy ◽  
Metallurgical Industry ◽  
Strengthening Mechanism ◽  
High Concentration ◽  
Eutectic Si ◽  
Dislocation Movement ◽  
Casting Aluminum ◽  
Tic Nanoparticles

In recent years, improvement of metals mechanical properties becomes one of the main challenges in materials and particularly in metallurgical industry. Mostly, an alloying process is typically applied to reach metals enhanced performance. This work, however, describes a different methodology, where WC and TiC nanoparticles used as a modifiers and then gas-dynamic treatment (GDT) are applied. These processes were investigated on a hypoeutectic casting aluminum A356 alloy. Microstructural evaluation illustrated that a coarse Al grains were refined as well as eutectic Si particles were formed. Subsequent mechanical properties tests revealed that aluminum elongation enhanced while strength remained unchanged. Addition of WC and TiC enhanced the elongation by 20-60%, depends on the mold area. A combined treatment, using GDT with addition of TiCN nanoparticles showed even improvement in both, elongation and strength by 18 and 19%, respectively. Moreover, based on the electron microscopy studies, this behavior was attributed to a grain-size strengthening mechanism, where a high concentration of grain boundaries serves as dislocation movement blockers

scholarly journals A Comparative Study on the Microstructures and Mechanical Properties of Al-10Si-0.5Mg Alloys Prepared under Different Conditions

Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 142
Author(s):  
Minghao Guo ◽  
Ming Sun ◽  
Junhui Huang ◽  
Song Pang
Keyword(s):  
Mechanical Properties ◽  
Cooling Rate ◽  
Grain Morphology ◽  
Strengthening Mechanism ◽  
Grain Structure ◽  
Sand Mold ◽  
Tensile Yield Strength ◽  
Fibrous Network ◽  
Eutectic Si ◽  
Microstructures And Mechanical Properties

Fabrication condition greatly influences the microstructures and properties of Al alloys. However, most of the available reports focus on a single fabrication technique, indicating there is still a lack of systematic comparisons among wider ranges of fabrication methods. In this paper, with conventional casting (via sand/Fe/Cu mold) and additive manufacturing (AM, via selective laser melting, SLM) methods, the effects of cooling rate (Ṫ) on the microstructures and mechanical properties of hypoeutectic Al-10Si-0.5Mg alloy are systematically investigated. The results show that with increasing cooling rate from sand-mold condition to SLM condition, the grain size (d) is continuously refined from ~3522 ± 668 μm to ~10 μm, and the grain morphology is gradually refined from coarse dendrites to a mixed grain structure composed of columnar plus fine grains (~10 μm). The eutectic Si particles are effectively refined from blocky shape under sand/Fe-mold conditions to needle-like under Cu-mold conditions, and finally to fine fibrous network under SLM condition. The tensile yield strength and elongation is greatly improved from 125 ± 5 MPa (sand-mold) to 262 ± 3 MPa (SLM) and from 0.8 ± 0.2% (sand-mold) to 4.0 ± 0.2% (SLM), respectively. The strengthening mechanism is discussed, which is mainly ascribed to the continuous refinement of grains and Si particles and an increase in super-saturation of Al matrix with increasing cooling rate.

The Effect of Ultrasonic Injection on the Microstructure and Mechanical Properties of A356 Alloy

2010 ◽  
Vol 638-642 ◽  
pp. 3960-3965 ◽  
Author(s):  
Byoung Il Kang ◽  
Dae Gyun Ko ◽  
Jeong Il Youn ◽  
Young Jig Kim
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
A356 Alloy ◽  
Casting Process ◽  
Primary Phase ◽  
Eutectic Phase ◽  
Research Activities ◽  
Plate Shape ◽  
Casting Aluminum ◽  
Intense Research

A356 alloy is one of the wide used casting aluminum alloys and intense research activities of worldwide on casting process or refinement agent and procedure. In this study, we attempted refinement on Al primary phase and eutectic phase of A356 alloy by ultrasonic injection into the melts. The effect of ultrasonic injection into the melts could be summarized as follows: the morphology of the Al primary phase was refined and changed shape from dendritic to nondendritic and the eutectic phase of A356 was also refined and changed morphology from dendritic to plate shape.

The Effect of Ultrasonic Injection on the Microstructure and Mechanical Properties of A356 Alloy

2010 ◽  
Vol 89-91 ◽  
pp. 285-289
Author(s):  
Byoung Il Kang ◽  
Dae Gyun Ko ◽  
Jeong Il Youn ◽  
Young Jig Kim
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
A356 Alloy ◽  
Casting Process ◽  
Primary Phase ◽  
Eutectic Phase ◽  
Research Activities ◽  
Plate Shape ◽  
Casting Aluminum ◽  
Intense Research

A356 alloy is one of the wide used casting aluminum alloys and intense research activities of worldwide on casting process or refinement agent and procedure. In this study, we attempted refinement on Al primary phase and eutectic phase of A356 alloy by ultrasonic injection into the melts. The effect of ultrasonic injection into the melts could be summarized as follows: the morphology of the Al primary phase was refined and changed shape from dendritic to nondendritic and the eutectic phase of A356 was also refined and changed morphology from dendritic to plate shape.

Aluminum A356 Reinforcement by Carbide Nanoparticles

2011 ◽  
Vol 13 ◽  
pp. 41-46 ◽  
Author(s):  
Konstantin Borodianskiy ◽  
Michael Zinigrad ◽  
Aharon Gedanken
Keyword(s):  
Particle Surface ◽  
A356 Alloy ◽  
High Resolution Electron Microscopy ◽  
Strengthening Mechanism ◽  
Microscopy Study ◽  
Dislocation Motion ◽  
Electron Microscopy Study ◽  
Resolution Electron ◽  
Tic Nanoparticles ◽  
Aluminum A356 Alloy

The main issue of the study is aluminum A356 alloy modification by TiC nanoparticles process. Nanoparticles of TiC were especially mechanochemically activated to remove the oxide layer on the particle surface in order to prevent its floating on the molten metal surface. Experimental results indicate that after T6 heat treatment the tensile strength of the modified alloy increased by 6.5%, yield strength increased by 9% and the elongation increased by 22%. A high resolution electron microscopy study shows that dislocation of the modified alloy concentrates near the grain boundary during the crystallization process, and these grain boundaries act as obstacles to dislocation motion. Based on these results, it was found that grain-size aluminum strengthening mechanism occurs in the nanoparticle carbide reinforcement process.

A New Technology to Improve the Elongation of A356 Alloy

2014 ◽  
Vol 217-218 ◽  
pp. 450-454
Author(s):  
Yi Jie Zhang ◽  
Nai Heng Ma ◽  
Xian Feng Li ◽  
Hao Wei Wang
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Automobile Industry ◽  
New Technology ◽  
A356 Alloy ◽  
Melt Processing ◽  
Microstructure Observation ◽  
Additional Equipment ◽  
Eutectic Si ◽  
Semi Solid

A356 alloy was widely used in automobile industry due to its excellent castability and comprehensive mechanical properties. But, with increasing demands of strictly safety of components, fatigue life of A356 alloy became the key properties which were considered seriously. To evaluate the time-consuming properties, elongation, as a replaced property, was employed for its easy testing and the relationship which was proportional to the fatigue life of materials. Semi-solid processing was proved that it can improve the elongation of materials while the mechanical properties still kept at the same level as original alloy. Presently, many semi-solid techniques were developed to produce various products, in which the additional equipment was necessary to form the semi-solid microstructure. Therefore, this work is aimed to development an easily technique to obtain the semi-solid microstructure. In present study, A356 alloy with typical semi-solid microstructure was obtained by addition of RE elements during melt processing. In addition, the melting and pouring process was kept the same as the normal gravity casting of A356 alloy. After the treatment, the elongation was 19.5% for A356 alloy with RE addition, which was much higher than that of 13% for normal A356 alloy. Microstructure observation showed that the morphology of Si was changed significantly, and the shape of spheroid was dominantly appeared other than short rod shape. The improvement of elongation was attributed to the morphology change of α-Al and eutectic Si.

MICROSTRUCTURES AND ROOM TEMPERATURE MECHANICAL PROPERTIES OF Al--6.3Zn--2.8Mg--1.8Cu CASTING ALUMINUM ALLOY

2013 ◽  
Vol 48 (2) ◽  
pp. 211-219 ◽  
Author(s):  
Guangyu YANG ◽  
Hongshuai MENG ◽  
Shaojun LIU ◽  
Yuanhao QI ◽  
Wanqi JIE
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Casting Aluminum Alloy ◽  
Casting Aluminum

scholarly journals Synergistic strengthening mechanism of copper matrix composite reinforced with nano-Al2O3 particles and micro-SiC whiskers

2021 ◽  
Vol 10 (1) ◽  
pp. 62-72
Author(s):  
Huanran Lin ◽  
Xiuhua Guo ◽  
Kexing Song ◽  
Jiang Feng ◽  
Shaolin Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Erosion Resistance ◽  
Strengthening Mechanism ◽  
Copper Matrix ◽  
Heavy Duty ◽  
Arc Erosion ◽  
Comprehensive Performance ◽  
Sic Whiskers ◽  
Copper Matrix Composite ◽  
Time And Energy

Abstract Although Cu–Al2O3 composites have good comprehensive performance, higher mechanical properties and arc erosion resistance are still required to meet heavy-duty applications such as electromagnetic railguns. In this work, a novel hybrid SiCw/Cu–Al2O3 composite was successfully prepared by combining powder metallurgy and internal oxidation. The microstructure and mechanical behavior of the SiCw/Cu–Al2O3 composite were studied. The results show that nano-Al2O3 particles and micro-SiCw are introduced into the copper matrix simultaneously. Well-bonded interfaces between copper matrix and Al2O3 particles or SiCw are obtained with improved mechanical and arc erosion resistance of SiCw/Cu–Al2O3 composite. The ultimate tensile strength of the SiCw/Cu–Al2O3 composite is 508.9 MPa, which is 7.9 and 56.1% higher than that of the Cu–Al2O3 composite and SiCw/Cu composite, respectively. The strengthening mechanism calculation shows that Orowan strengthening is the main strengthening mechanism of the SiCw/Cu–Al2O3 composite. Compared with Cu–Al2O3 composite, the hybrid SiCw/Cu–Al2O3 composite has lower arc time and energy and better arc stability.

scholarly journals Assessing the Flexural Properties of Epoxy Composites with Extremely Low Addition of Cellulose Nanofiber Content

2020 ◽  
Vol 10 (3) ◽  
pp. 1159 ◽  
Author(s):  
Yingmei Xie ◽  
Hiroki Kurita ◽  
Ryugo Ishigami ◽  
Fumio Narita
Keyword(s):  
Mechanical Properties ◽  
Epoxy Resin ◽  
Flexural Modulus ◽  
Strengthening Mechanism ◽  
Short Fiber ◽  
Cellulose Nanofiber ◽  
Resin Matrix ◽  
Element Analysis ◽  
Epoxy Resin Matrix ◽  
The Matrix

Epoxy resins are a widely used common polymer due to their excellent mechanical properties. On the other hand, cellulose nanofiber (CNF) is one of the new generation of fibers, and recent test results show that CNF reinforced polymers have high mechanical properties. It has also been reported that an extremely low CNF addition increases the mechanical properties of the matrix resin. In this study, we prepared extremely-low CNF (~1 wt.%) reinforced epoxy resin matrix (epoxy-CNF) composites, and tried to understand the strengthening mechanism of the epoxy-CNF composite through the three-point flexural test, finite element analysis (FEA), and discussion based on organic chemistry. The flexural modulus and strength were significantly increased by the extremely low CNF addition (less than 0.2 wt.%), although the theories for short-fiber-reinforced composites cannot explain the strengthening mechanism of the epoxy-CNF composite. Hence, we propose the possibility that CNF behaves as an auxiliary agent to enhance the structure of the epoxy molecule, and not as a reinforcing fiber in the epoxy resin matrix.

scholarly journals Achievement of High Strength and Ductility in Al–Si–Cu–Mg Alloys by Intermediate Phase Optimization in As-Cast and Heat Treatment Conditions

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 647 ◽  
Author(s):  
Bingrong Zhang ◽  
Lingkun Zhang ◽  
Zhiming Wang ◽  
Anjiang Gao
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Intermediate Phase ◽  
High Strength ◽  
Mg Alloys ◽  
Artificial Ageing ◽  
Treatment Conditions ◽  
Eutectic Si

In order to obtain high-strength and high-ductility Al–Si–Cu–Mg alloys, the present research is focused on optimizing the composition of soluble phases, the structure and morphology of insoluble phases, and artificial ageing processes. The results show that the best matches, 0.4 wt% Mg and 1.2 wt% Cu in the Al–9Si alloy, avoided the toxic effect of the blocky Al2Cu on the mechanical properties of the alloy. The addition of 0.6 wt% Zn modified the morphology of eutectic Si from coarse particles to fine fibrous particles and the texture of Fe-rich phases from acicular β-Fe to blocky π-Fe in the Al–9Si–1.2Cu–0.4Mg-based alloy. With the optimization of the heat treatment parameters, the spherical eutectic Si and the fully fused β-Fe dramatically improved the ultimate tensile strength and elongation to fracture. Compared with the Al–9Si–1.2Cu–0.4Mg-based alloy, the 0.6 wt% Zn modified alloy not only increased the ultimate tensile strength and elongation to fracture of peak ageing but also reduced the time of peak ageing. The following improved combination of higher tensile strength and higher elongation was achieved for 0.6 wt% Zn modified alloy by double-stage ageing: 100 °C × 3 h + 180 °C × 7 h, with mechanical properties of ultimate tensile strength (UTS) of ~371 MPa, yield strength (YS) of ~291 MPa, and elongation to fracture (E%) of ~5.6%.

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