Effect of Ultrasonic Treatment on the Eutectic Phase and Cu Content in the Al Matrix of Large-Scale 2219 Al Alloy Ingot

2020 ◽  
pp. 1045-1051
Author(s):  
Li Zhang ◽  
Xiaoqian Li ◽  
Ripeng Jiang ◽  
Ruiqing Li ◽  
Lihua Zhang
Keyword(s):  
Ultrasonic Treatment ◽  
Large Scale ◽  
Eutectic Phase ◽  
Al Alloy ◽  
Alloy Ingot ◽  
Cu Content ◽  
Al Matrix

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

scholarly journals A Study on the Effect of Ultrasonic Treatment on the Microstructure of Sn-30 wt.% Bi Alloy

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1870
Author(s):  
Shuo Wang ◽  
Jinwu Kang ◽  
Xiaopeng Zhang ◽  
Zhipeng Guo
Keyword(s):  
Ultrasonic Treatment ◽  
Acoustic Streaming ◽  
Eutectic Structure ◽  
Eutectic Phase ◽  
Ultrasonic Cavitation ◽  
Mixed Effect ◽  
Temperature Range ◽  
Different Temperatures

The effect of ultrasonic treatment on the microstructure of Sn-30 wt.% Bi alloy was studied at different temperatures. Results showed that the ultrasonic treatment could effectively refine the microstructure of Sn-30 wt.% Bi alloy at a temperature range between the liquidus and solidus. Application of the ultrasound could fragment the primary Sn dendrites during solidification due to a mixed effect of ultrasonic cavitation and acoustic streaming. The divorced eutectic formed when the ultrasonic treatment was applied for the whole duration of the solidification. The eutectic phase grew and surrounded the primary Sn dendrite, and pure Bi phase grew in between the Sn dendritic fragments. The mechanism of the fragmentation of dendrites and the divorced eutectic structure by ultrasonic treatment was discussed.

scholarly journals Effect of Structural Modification on Corrosion Behavior of Hypo Eutectic Al-Si Alloy

2018 ◽  
Vol 778 ◽  
pp. 16-21
Author(s):  
Muhammad Mansoor ◽  
Muhammad Kamran Yaseen ◽  
Shaheed Khan
Keyword(s):  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Earth Metal ◽  
Alloy System ◽  
Eutectic Phase ◽  
Al Alloy ◽  
General Corrosion ◽  
Corrosion Properties ◽  
Unmodified Alloy ◽  
Cast Alloys

Al-Si eutectic cast alloys are widely used in aeronautical and automobile industries where significantly high strength, toughness and wear resistance are required. This class of cast alloys exhibit relatively low corrosion resistance in brine environments. The mechanical properties of the alloy system mainly depend upon the shape of Si rich eutectic phase, which mainly has acicular geometry. In present research, the effect of modified microstructure of 12 wt. % Si-Al alloy on corrosion behavior was studied. The needle like Si rich eutectic phase was modified to disperse spherical structure using rare earth metal halides. The corrosion rate and pitting behavior of modified and unmodified alloy were evaluated in 3.5% NaCl solution by general corrosion for calculated time. It was observed that the corrosion rate and pitting tendency of modified alloy had been appreciably reduced as compare to unmodified alloy. The improvement of corrosion properties were the attributes of changed morphology and distribution of Si rich eutectic phase.

scholarly journals Utilization of SiC and Cu Particles to Enhance Thermal and Mechanical Properties of Al Matrix Composites

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2770 ◽  
Author(s):  
Dongxu Wu ◽  
Congliang Huang ◽  
Yukai Wang ◽  
Yi An ◽  
Chuwen Guo
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
High Thermal Conductivity ◽  
Low Density ◽  
Matrix Composites ◽  
Thermal And Mechanical Properties ◽  
Cu Content ◽  
Sic Particles ◽  
Al Matrix Composites ◽  
Al Matrix

In this work, SiC and Cu particles were utilized to enhance the thermal and mechanical properties of Al matrix composites. The ball-milling and cold-compact methods were applied to prepare Al matrix composites, and the uniform distribution of SiC and Cu particles in the composite confirms the validity of our preparation method. After characterizing the thermal conductivity and the compressibility of the prepared composites, results show that small particles have a higher potential to improve compressibility than large particles, which is attributed to the size effect of elastic modulus. The addition of SiC to the Al matrix will improve the compressibility behavior of Al matrix composites, and the compressibility can be enhanced by 100% when SiC content is increased from 0 to 30%. However, the addition of SiC particles has a negative effect on thermal conductivity because of the low thermal conductivity of SiC particles. The addition of Cu particles to Al-SiC MMCs could further slightly improve the compressibility behavior of Al-SiC/Cu MMCs, while the thermal conductivity could be enhanced by about 100% when the Cu content was increased from 0 to 30%. To meet the need for low density and high thermal conductivity in applications, it is more desirable to enhance the specific thermal conductivity by enlarging the preparation pressure and/or sintering temperature. This work is expected to supply some information for preparing Al matrix composites with low density but high thermal conductivity and high compressibility.

Microstructure, Mechanical Properties, Electric and Thermal Conductivity of the As-Extruded Al-x(1.0 wt.% Zn + 0.5 wt.% Cu) Alloys (x = 1, 2 and 4)

2020 ◽  
Vol 20 (7) ◽  
pp. 4248-4252
Author(s):  
Yong-Ho Kim ◽  
Hyo-Sang Yoo ◽  
Hyeon-Taek Son
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Intermetallic Compounds ◽  
Extrusion Process ◽  
Al Alloy ◽  
Homogenization Treatment ◽  
Solid Solution Strengthening ◽  
Cu Content ◽  
Average Grain Size ◽  
Solution Strengthening

In this research, effects of Zn and Cu content on microstructure, mechanical properties, electric and thermal conductivity of the as-extruded Al-x(Zn+0.5Cu) alloys were investigated. As the content of Zn and Cu increased, the area ratio of Al2Cu intermetallic compounds increased. After homogenization treatment and extrusion process, most of Al2Cu intermetallic compounds was disappeared due to solution in Al matrix of Cu atoms. As the (Zn+0.5Cu) content increased from 1 to 2 wt.%, the average grain size decreased remarkably from 645 to 227 μm due to the dynamic recrystallization caused by the solute Zn and Cu atoms during the extrusion. With increasing Zn and Cu additions, the thermal conductivity was decreased from 225 (x = 1) to 208 (x = 2) and 183 W/mK (x = 4) due to electric scattering by solute Zn and Cu atoms. The ultimate tensile strength (UTS) of the as-extruded Al-x(1Zn+0.5Cu) alloys improved remarkably from 77 (x = 1) to 142 MPa (x = 4) as Zn and Cu content increased, and the elongation increased from 30 to 33%. This improvement in the strength resulted from the grain refinement and solid solution strengthening due to the solute Zn and Cu atoms. The Zn and Cu addition in Al alloy played an important role in thermal conductivity and mechanical properties.

Hillocks on half-micron aluminum lines

1991 ◽  
Vol 6 (9) ◽  
pp. 1817-1819 ◽  
Author(s):  
Carey A. Pico ◽  
Tom D. Bonifield
Keyword(s):  
Grain Boundary ◽  
Large Scale ◽  
Boundary Diffusion ◽  
Al Alloy ◽  
Grain Sizes ◽  
Integrated Devices ◽  
Hillock Formation ◽  
New Type ◽  
Hillock Growth ◽  
Bamboo Structure

A new regime of hillock growth has been observed in patterned Al98.5 W.%Si1.0 Wt.%-Cuo0.5 wt.% films. The “surface” hillock and “side” hillock, which have been seen previously, form on patterned metal lines having linewidths greater than the larger Al alloy grain sizes (∼3 μm). None is seen on the fabricated lines having linewidths between 0.9 and 2 μm where long-range grain boundary diffusion cannot occur because of its bamboo structure. However, a new type of hillock, the “line hillock”, occurs in structures having linewidths of 0.6 μm. The presence of this last type of hillock is inconsistent with the current understanding of hillock formation and may present severe restrictions on the down-sizing of ultra–large–scale integrated devices.

Simulation and Experimental Mechanical Properties of SiCn/2024 Al Alloy Co-Continuous Composites

2013 ◽  
Vol 712-715 ◽  
pp. 997-1001 ◽  
Author(s):  
Yi Wei Qin ◽  
Sen Kai Lu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Cycle Fatigue ◽  
Elasticity Modulus ◽  
Failure Strain ◽  
Simulated Data ◽  
Al Alloy ◽  
Cycle Fatigue ◽  
Simulation Code ◽  
Al Matrix

The experimental and numerical simulations of mechanical properties of co-continuous composites SiCn/Al produced by infiltration of SiC preforms with melted 2024 Al alloy using Solidwork2012 Simulation code were carried out. The results showed that ultimate tensile strengths of SiCn/Al up to 410 MPa at a failure strain of up to 0.7% without any heat treatment. The compression strength was up to 710 MPa with 2% strain to failure. The composites show an excellent resistance to high cycle fatigue. Fatigue life for specimen was 4.5×105cycles for 250 MPa while R=-1.0, and 4.9×105cycles for 164 MPa while R=-0.05. Simulated data shows there is different mechanical behavior between SiC structs and Al matrix, difference of elasticity modulus of two constituents occasion difference of generated deflection, Al has taken place large deformation; Due to structural characteristic of SiC, the force on each rib affects other adjacent rib, Al and SiC restrict each other to prevent from producing the strain.

scholarly journals Unravelling the characteristics of Al-alloy corrosion at the atomic to nanometre scale by transmission electron microscopy

2020 ◽  
Vol 326 ◽  
pp. 01007
Author(s):  
Shravan K. Kairy ◽  
Nick Birbilis
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Al Alloy ◽  
Second Phase ◽  
Clear Understanding ◽  
Transmission Electron ◽  
Second Phase Particles ◽  
Al Matrix

The localised corrosion associated with Mg2Si in the Al-matrix of an Al-Mg-Si alloy was studied in 0.1 M NaCl at pH 6 by quasi in-situ transmission electron microscopy. Herein, physical imaging of corrosion at the atomic to nanometre scale was performed. Phase transformation and subsequent chemical composition variations associated with the localised corrosion of Mg2Si were studied. It was observed that corrosion initiated upon Mg2Si, often preferentially at the interface with the Al-matrix, and propagated until Mg2Si was completely dealloyed by Mg-dissolution, resulting in an amorphous SiO-rich phase remnant. The SiO-rich remnant became electrochemically inert and did not initiate corrosion in the Al-matrix. This study provides a clear understanding on the localised corrosion of Al-alloys associated with Mg2Si. In addition, the methodology followed in this study can also be applied to understand the role of precipitates and second phase particles in the localised corrosion of Al-alloy systems.

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