scholarly journals Pure Aluminum Structure and Mechanical Properties Modified by Al2O3 Nanoparticles and Ultrasonic Treatment

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1199 ◽  
Author(s):  
Zhukov ◽  
Kozulin ◽  
Khrustalyov ◽  
Kahidze ◽  
Khmeleva ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ultrasonic Treatment ◽  
Bulk Material ◽  
Pure Aluminum ◽  
Homogeneous Distribution ◽  
Al2o3 Nanoparticles ◽  
Aluminum Oxide Nanoparticles ◽  
Average Grain Size ◽  
Commercial Purity Aluminum ◽  
Strengthening Particles

This paper examines dispersion hardened alloys based on commercial-purity aluminum obtained by permanent mold casting with the addition of aluminum oxide nanoparticles. Ultrasonic treatment provides a synthesis of non-porous materials and a homogeneous distribution of strengthening particles in the bulk material, thereby increasing the mechanical properties of pure aluminum. It is shown that the increase in the alloy hardness, yield stress, ultimate tensile strength, and lower plasticity depend on the average grain size and a greater amount of nanoparticles in the alloy.

Synthesis of Al-Al3Ti In Situ Metal Matrix Composites by Salt Route and Evaluation of their Mechanical Properties

2014 ◽  
Vol 984-985 ◽  
pp. 280-284 ◽  
Author(s):  
S.A. Kori ◽  
S.L. Biradar ◽  
Virupaxi Auradi
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Microstructural Characterization ◽  
Homogeneous Distribution ◽  
Matrix Composites ◽  
Commercial Purity Aluminum ◽  
Microstructural Studies

Current work, aims at preparation and characterization of Al-Al3Ti in-situ metal matrix composites with varying percentage of in-situ Al3Ti (3 and 5%) reinforcement. The composites were prepared by the salt route involving reaction of commercial purity aluminum (99.7%) and potassium titanium flourate halide (K2TiF6) salt at a reaction temperature of 800°C and with 60min. holding time. The prepared composites were subjected to microstructural studies using Scanning Electron Microscope. Further, the work aims at evaluating mechanical properties of the prepared composites as per ASTM standards. Microstructural characterization using SEM revealed blocky morphology of Al3Ti intermetallics with fairly homogeneous distribution. Insitu Al-Al3Ti composites have shown better mechanical properties when compared to the unreinforced Al matrix.

Effect of Ultrasonic Treatment on the Grain Refinement and Mechanical Properties of AZ91 Magnesium Alloy

2012 ◽  
Vol 710 ◽  
pp. 463-468 ◽  
Author(s):  
Pramod Bhingole ◽  
Gajanan Chaudhari
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Ultrasonic Vibration ◽  
Ultrasonic Treatment ◽  
High Intensity ◽  
Intermetallic Phase ◽  
Ultrasonic Vibrations ◽  
Az91 Magnesium Alloy ◽  
Average Grain Size ◽  
Az91 Magnesium

The present study examines the microstructural evolution and mechanical properties of AZ91 magnesium alloy solidified under high intensity ultrasonic treatment (UST). High intensity ultrasonic vibrations were introduced isothermally below the liquidus temperature into the solidifying AZ91 alloy for the refinement of primary α-Mg grains and β-Mg17Al12intermetallic phase.Various microstructures were produced using different intensity of ultrasonic vibration at a constant temperature and fixed duration of UST. Without any ultrasonic treatment, the structure contains dendrites of primary α-Mg phase which are coarser and non-uniform in size. Nearly uniform, equiaxed grains with continuous and uniform network of intermetallic phase segregated along the grain boundaries were obtained in alloy subjected to high intensity ultrasonic vibration. The average grain size in this case decreased drastically from 300 μm for (without UST) to 17 μm (with UST at intensity of 4 kW/cm2). Vickers hardness also increased steadily with increase in ultrasonic intensity. The mechanisms for microstructural refinement are discussed and it is concluded that the fine uniform grain structure achieved under ultrasonic vibrations is attributed to the cavitation and the acoustic flow induced by ultrasonic vibrations.

Effect of Sc, Zr Grain Refiner on the Microstructure and Mechanical Properties of Pure Aluminum

2014 ◽  
Vol 508 ◽  
pp. 16-21 ◽  
Author(s):  
Ai Wu Yu ◽  
Cheng Gang Yang ◽  
Shang Lin Wang ◽  
Fen Cheng Liu ◽  
Qiang Zheng
Keyword(s):  
Mechanical Properties ◽  
Pure Aluminum ◽  
Eutectic Point ◽  
Strengthening Effect ◽  
Grain Refiner ◽  
Solid Solution Strengthening ◽  
Fine Grain ◽  
Microstructure And Mechanical Properties ◽  
Average Grain Size ◽  
Columnar Grains

The influence of grain refiner on the microstructure and mechanical properties of pure aluminum was investigated by separate and combined addition trace ScZr elements. The results show that the grain refinement effect of 0.2%Zr added alone is better than that of 0.2%Sc, each of them separate addition can make the strength and hardness of alloys increased obviously, and the decrease of the ductility is not remarkable, but the hardness increase of the alloy with 0.2%Sc is more significant than 0.2%Zr because of the strongly solid solution strengthening of Sc. While, the combined addition of 0.2%Sc and 0.2%Zr possesses the most excellent grain refining effect and change the growth morphology from columnar grains to equiaxed ones, the average grain size of the alloy is dropped to only about 100μm, and the strength, plastic and hardness of the alloy meet the reasonable matching, which is largely attributed to the effectively reduce of the Al-Sc eutectic point and the formation of Al3(Sc, Zr) composite particles, These Al3(Sc, Zr) particles can not only keep all the beneficial effect of A13Sc but can act as extremely effective nucleation sites of α (Al) and cause strongly fine-grain strengthening effect.

FABRICATION OF NANOSTRUCTURED TUBE BY A NOVEL SPD PROCESS: ACCUMULATIVE SPIN-BONDING (ASB)

2012 ◽  
Vol 05 ◽  
pp. 342-349
Author(s):  
M. S. MOHEBBI ◽  
A. AKBARZADEH
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Optical Microscopy ◽  
Grain Refinement ◽  
Pure Aluminum ◽  
High Strength ◽  
Commercially Pure ◽  
Tension Tests ◽  
Average Grain Size

A novel SPD process for manufacturing high strength tubes and cylinders titled as accumulative spin-bonding (ASB) is proposed. This process is applied to a commercially pure aluminum up to four cycles and its effects on the microstructure and mechanical properties are examined by optical microscopy, TEM, microhardness and tension tests. The results show that ultra-fine grains are developed during the process leading to a nanostructure with average grain size in order of 150 nm. Mechanical properties indicate that while the hardness of outer layers is more than inner ones, the hardness and its homogeneity is increased by increasing the ASB cycles. As a result of grain refinement and the scheme of hardness development, the yield and tensile strength of material are increased significantly up to the values of 194 and 235 MPa, respectively.

Effects of Ultrasonic Treatment on Microstructure and Properties of Al-Based Composites Reinforced by In Situ Al2O3 Nanoparticles

2016 ◽  
Vol 35 (2) ◽  
pp. 169-175
Author(s):  
Cunguang Chen ◽  
Zhimeng Guo ◽  
Ji Luo ◽  
Wenwen Wang ◽  
Junjie Hao
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Ultrasonic Treatment ◽  
Tensile Tests ◽  
Al2o3 Nanoparticles ◽  
Displacement Reaction ◽  
Slight Improvement ◽  
Intermetallic Particles ◽  
Microstructural Effects

AbstractAn investigation on the microstructure of as-cast Al-Mg-Cu composites reinforced by in situ nano-sized Al2O3 dispersoids with ultrasonic treatment showed that ultrasonic treatment of the melt prior to casting had a significant effect on the size and sphericity of α-Al dendrites as well as on the size, continuity and sphericity of intermetallic particles (Al2CuMg) formed during cooling and solidification of the composite. More importantly, Al2O3 nanoparticles were uniformly distributed inside the grains, which were in situ produced by the displacement reaction between Al and CuO in the melt under ultrasonic treatment. The microstructural effects were mainly attributed to the cavitation and streaming phenomena which took place during ultrasonic treatment in the melt. The mechanical properties were investigated by tensile tests and hardness measurements. Ultrasonic treatment caused a significant increase in the yield strength (~43%), ultimate tensile strength (~32%) and hardness (~13%), and simultaneously slight improvement in the ductility.

Surface Modification and its Influence on the Microstructure and Creep Resistance of Nickel Based Superalloy René 77 / Modyfikacja Powierzchniowa Oraz Jej Wpływ Na Mikrostrukture I Wytrzymałosc Na Pełzanie Odlewów Z Nadstopu Niklu Ren´E 77

2013 ◽  
Vol 58 (1) ◽  
pp. 95-98 ◽  
Author(s):  
M. Zielinska ◽  
J. Sieniawski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Surface Modification ◽  
Turbine Blades ◽  
Processing Parameters ◽  
Grain Structure ◽  
Creep Tests ◽  
Cobalt Aluminate ◽  
Nickel Based Superalloy ◽  
Average Grain Size

Superalloy René 77 is very wide used for turbine blades, turbine disks of aircraft engines which work up to 1050°C. These elements are generally produced by the investment casting method. Turbine blades produced by conventional precision casting methods have coarse and inhomogeneous grain structure. Such a material often does not fulfil basic requirements, which concern mechanical properties for the stuff used in aeronautical engineering. The incorporation of controlled grain size improved mechanical properties. This control of grain size in the casting operation was accomplished by the control of processing parameters such as casting temperature, mould preheating temperature, and the use of grain nucleates in the face of the mould. For nickel and cobalt based superalloys, it was found that cobalt aluminate (CoAl2O4) has the best nucleating effect. The objective of this work was to determine the influence of the inoculant’s content (cobalt aluminate) in the surface layer of the ceramic mould on the microstructure and mechanical properties at high temperature of nickel based superalloy René 77. For this purpose, the ceramic moulds were made with different concentration of cobalt aluminate in the primary slurry was from 0 to 10% mass. in zirconium flour. Stepped and cylindrical samples were casted for microstructure and mechanical examinations. The average grain size of the matrix ( phase), was determined on the stepped samples. The influence of surface modification on the grain size of up to section thickness was considered. The microstructure investigations with the use of light microscopy and scanning electron microscopy (SEM) enable to examine the influence of the surface modification on the morphology of ’ phase and carbides precipitations. Verification of the influence of CoAl2O4 on the mechanical properties of castings were investigated on the basis of results obtained form creep tests.

Research Advance in Harmful Effects and Removal of Impurity Fe from Al and Al Alloys

2011 ◽  
Vol 295-297 ◽  
pp. 751-759 ◽  
Author(s):  
Hua Shen ◽  
Wei Dong Yang ◽  
He Liang ◽  
Guang Chun Yao
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Pure Aluminum ◽  
Al Alloys ◽  
Precipitation Method ◽  
Filtration Method ◽  
Purification Methods ◽  
Research Advance ◽  
Harmful Effects

The presence of Fe and harmful effects on mechanical properties of pure aluminum and aluminum alloys are introduced. Several purification methods are reviewed, but all of them are of definite limitations. It is effective that precipitation method, filtration method and centrifugal division method are integrated.

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