Particle Redistribution and Grain Refinement during Processing by Hydrostatic Extrusion

2008 ◽  
Vol 584-586 ◽  
pp. 541-546 ◽  
Author(s):  
Kinga Wawer ◽  
Małgorzata Lewandowska ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Grain Refinement ◽  
Hydrostatic Extrusion ◽  
Strength Increase ◽  
Two Phase ◽  
Size Refinement ◽  
Cast Alloys ◽  
Tensile Strength Increase

In this study particle redistribution and grain size refinement induced by hydrostatic extrusion (HE) have been studied in two Al-Si cast alloys (Al-9%Si and Al-11%Si). It has been found that HE results in a significant changes in particle shape, size and distribution which was revealed by SEM observations and quantified using stereological parameters. At the same time, significant grain refinement down to ~100 nm in diameter takes place in aluminium phase. Such a microstructure evolution affects substantially the mechanical properties of two-phase alloys. The yield strength and tensile strength increase over two times whereas the plasticity only slightly decreases.

Effect of Composite Master Alloy on Mechanical Properties and Electrochemical Corrosion of ZL101 Alloy

2013 ◽  
Vol 749 ◽  
pp. 407-413
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Ji Ping Ren ◽  
Min Peng ◽  
Shi Yang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Grain Refinement ◽  
Master Alloy ◽  
Mass Fraction ◽  
Electrochemical Corrosion ◽  
Corrosion Performance ◽  
Obvious Effect ◽  
Mechanical Properties And Corrosion

The mechanical properties and corrosion performances of the ZL101 alloy modified by the composite master alloy were investigated. The results showed that the master alloy had not only obvious effect of grain refinement, but also a significant role in refining dendrite grain of ZL101 alloy. The grain size decreased dramatically from 150μm to 62μm when the addition of composite master alloy is up to 0.5%(mass fraction) and the temperature is 720 for 30 minutes,. Its tensile strength and elongation increased by 27% and 42% respectively. The grain refinement of ZL101 alloy decreased its corrosion performance. The morphology of Si changed into globular from needle modified by NaF, instead of AlTiB.

Optimization of Particle Size and Distribution by Hydrostatic Extrusion

2007 ◽  
Vol 561-565 ◽  
pp. 869-872 ◽  
Author(s):  
Małgorzata Lewandowska ◽  
Kinga Wawer
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Aluminium Alloys ◽  
Hydrostatic Extrusion ◽  
Nanometer Scale ◽  
Second Phase ◽  
Size Refinement ◽  
Second Phase Particles ◽  
Fatigue And Fracture

Hydrostatic extrusion (HE) as a method of metals forming is known for about 100 years. Recently, it has been utilized as an efficient way of grain size refinement down to nanometer scale. In the case of engineering metals, HE processing alters not only grain size but also second phase particles such as intermetallic inclusions and precipitates. During HE processing, these particles significantly change their size, shape and spatial distribution. These changes are accompanied by improvement in properties of processed metals such as fatigue and fracture toughness. In the present work, changes of second phase particles induced by HE are described in a quantitative way for aluminium alloys. Their impact on mechanical properties is also discussed.

Research on the Strength Improvement of 7A04 Aluminum Alloy

2012 ◽  
Vol 488-489 ◽  
pp. 19-21
Author(s):  
Chao Jue Yi ◽  
Peng Cheng Zhai ◽  
Li Zhou Dong ◽  
Qi Hao Fu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Grain Refinement ◽  
Cryogenic Treatment ◽  
The Impact ◽  
Strength Improvement

By using cryogenic treatment on 7A04 aluminum alloy tested with micrographic analysis and mechanical properties test, we studied the impact on mechanical properties of 7A04 aluminum alloy The results showed that the strength of 7A04 aluminum alloy could be highly increased and the grain size would be reduced in the process through being treated in 480°C/80min + aging in 120°C/4h + cryogenic treatment + aging at 120°C/16h.7A04 aluminum alloy are more fully recrystallized to grain refinement and the tensile strength of it can be increased to 720Mpa after the treatment.

Effect of Trace Boron on Microstructure and Mechanical Properties of Ti-9V-3Al-3Cr-3Zr-3.5Mo Alloy

2011 ◽  
Vol 194-196 ◽  
pp. 1287-1290
Author(s):  
Xu Liang Liu ◽  
Yun Qing Ma ◽  
Shui Yuan Yang ◽  
Yun Neng Wang ◽  
Cui Ping Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Grain Refinement ◽  
Microstructure And Mechanical Properties

The effects of trace boron on microstructure and mechanical properties of β type Ti-9V-3Al-3Cr-3Zr-3.5Mo (wt. %) alloy have been investigated in this study. Upon the addition of 0.02 wt. % boron, the grain size of the B-modified alloy was almost four times smaller than that of the B-free alloy. Accordingly, the tensile strength and elongation of B-modified alloy increased from 712 MPa and 14.6 % to 813 MPa and 17.9 %, respectively, mainly due to the effect of grain refinement.

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.

Improvement of Mechanical Properties of 7475 Aluminium Alloy by the Combination of SPD Processing and Annealing

2011 ◽  
Vol 690 ◽  
pp. 311-314 ◽  
Author(s):  
Kinga Wawer ◽  
Małgorzata Lewandowska ◽  
Krzysztof Jan Kurzydlowski
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Aluminium Alloy ◽  
True Strain ◽  
Hydrostatic Extrusion ◽  
Synergic Effect ◽  
Size Refinement ◽  
Low Temperature Annealing ◽  
Heat Treated ◽  
Precipitate Strengthening

In the present study, SPD processing was combined with annealing in order to obtain synergic effect of grain size refinement and precipitate strengthening. Samples of 7475 alloy were solution heat treated, water quenched and then subjected to hydrostatic extrusion with a total true strain of about 4. Hydrostatic extrusion resulted in a significant grain refinement from 70 mm to about 70 nm. The samples were subsequently annealed at temperatures inducing the formation of nano-precipitates. The investigations of the structure and mechanical properties of the samples subjected to SPD and annealing revealed different precipitation path in micro- and nano-grained samples. Also, it was found that the combination of HE processing and low temperature annealing results in the formation of nano-precipitates in nano-grained structures which effectively strengthen nano-aluminium alloy.

Study on the Microstructure Control and the Variation of Mechanical Properties of Pearlitic Steel

2014 ◽  
Vol 988 ◽  
pp. 173-176
Author(s):  
Lun You Li ◽  
Yu Liang ◽  
Ze Min Wei ◽  
Hu Xiong
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Great Influence ◽  
Interlamellar Spacing ◽  
Pearlitic Steel ◽  
Isothermal Transformation ◽  
Strength Increase ◽  
Isothermal Temperature ◽  
Fine Grain

The effect of austenitizing temperatures and isothermal transformation temperatures on microstructure size and mechanical properties of 70 steel was studied. The experimental results show that the grain size increases with the increasing of austenitizing temperature. And the tensile strength increased with isothermal temperature decreasing. The grain size has a great influence on tensile strength. The strength increase of the samples with fine grain is greater than the samples with coarse grain. With the decreasing of isothermal temperature, the pearlite colony size and interlamellar spacing decreases and the reduction of area of the specimens increase.

The Influence of Hydrostatic Extrusion on the Microstructure of 6082 Aluminium Alloy

2006 ◽  
Vol 114 ◽  
pp. 145-150 ◽  
Author(s):  
Pawel Widlicki ◽  
Halina Garbacz ◽  
Małgorzata Lewandowska ◽  
Wacław Pachla ◽  
Mariusz Kulczyk ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Plastic Deformation ◽  
Grain Size ◽  
Tensile Strength ◽  
Severe Plastic Deformation ◽  
Light Microscopy ◽  
Aluminium Alloy ◽  
Extrusion Process ◽  
Hydrostatic Extrusion ◽  
Fine Grained

Hydrostatic extrusion can be viewed as one of the methods of Severe Plastic Deformation, SPD, for the fabrication of ultra-fine grained alloys which causes a significant increase in the mechanical properties such as tensile strength and hardness. In the present study the microstructure of 6082 aluminium alloy after hydrostatic extrusion was investigated. Hydroextrusion was performed in three steps with accumulated true strains of 1.34, 2.73 and 3.74 respectively. Microstructural observations were carried out using SEM, TEM and light microscopy. Grain and inclusion sizes, shapes and distribution were investigated in the HE processed samples. The study has shown that the hydrostatic extrusion process results in a profound refinement of both the grain size and the inclusions in 6082 aluminium alloy.

Hot-Extruded Microstructure and Mechanical Properties of Mg-Al-Sn Alloys

2010 ◽  
Vol 297-301 ◽  
pp. 1037-1041
Author(s):  
Young Mo Kim ◽  
Soon Sub Park ◽  
Seul Ki Park ◽  
Hyeon Taek Son ◽  
Jae Seol Lee
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Tensile Strength ◽  
Fine Particles ◽  
Extrusion Direction ◽  
Hot Extrusion ◽  
Eutectic Phase ◽  
Al Content ◽  
Cast Alloys ◽  
Mg2sn Phase

The microstructure of as-cast Mg-xAl-2Sn alloys consists of an α-Mg matrix, a Mg17Al12 eutectic phase and a Mg2Sn phase. In as-cast alloys, the Mg17Al12 eutectic phase was located at along grain boundaries. The eutectic phase of the extruded alloys was elongated in the extrusion direction and crushed into fine particles because of deformation during hot extrusion, and the grain size was refined with an increased Al content. The maximum values of the yield strength and tensile strength were 240 MPa and 300 MPa at 9 wt.% containing Al element, respectively.

Effect of Cerium Addition on the Microstructure and Mechanical Properties of Al-Zn-Mg-Cu Alloy

2008 ◽  
Vol 279 ◽  
pp. 97-103 ◽  
Author(s):  
Anil K. Chaubey ◽  
S. Mohapatra ◽  
B. Bhoi ◽  
J.L. Gumaste ◽  
Barada Kanta Mishra ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Grain Refinement ◽  
Strengthening Mechanism ◽  
Casting Method ◽  
Cu Alloy ◽  
Microstructure And Mechanical Properties ◽  
Cast Alloys ◽  
Mould Casting

Al–8.6Zn–2.6Mg-2.4Cu–xCe(x = 0–0.4 wt. %) alloys were prepared by metal mould casting method, the effects of Ce on the microstructure and mechanical properties of the alloys were investigated. The results showed that the dendrite as well as grain size were refined by the addition of Ce, and the best refinement was obtained in 0.25 wt % Ce containing alloy. The main phases in the as-cast alloys were α-Al, Mg-Zn32, Mg32 (Al, Zn)49, and Al4Ce phase was found in the alloys containing more than 0.1%Ce. The addition of Ce improved the mechanical properties of the alloys. The strengthening mechanism was attributed to grain refinement and compound reinforced

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