Enhancement of mechanical properties and grain size refinement of commercial purity aluminum 1050 processed by ECAP

2007 ◽  
Vol 458 (1-2) ◽  
pp. 226-234 ◽  
Author(s):  
E.A. El-Danaf ◽  
M.S. Soliman ◽  
A.A. Almajid ◽  
M.M. El-Rayes
2011 ◽  
Vol 66-68 ◽  
pp. 845-849
Author(s):  
Xiao Wei Chen ◽  
Ya Gao ◽  
Hong Liang Zhao ◽  
Kang Rong Weng ◽  
Bao Feng Zhang

Al-3Ti-0.5B master alloy was prepared by reaction of Ti sponge, KBF4with aluminum melt. The morphology and distribution of the second phases effected by the feeding methods have been discussed. And the grain refining performance and the resistance to fading of the master alloy were investigated. The result shows that the Al-3Ti-0.5B master alloy which was prepared by adding mixture of Ti sponge and KBF4power into molten aluminum contains a large number of granular TiB2phase and blocky TiAl3phase. The average grain size of commercial purity aluminum was refined from 920μm to 120μm by adding 0.5wt.% of the master alloy. And the refining performance of the master alloy shows no obviously fading phenomenon when the holding time up to 30min.


2012 ◽  
Vol 706-709 ◽  
pp. 1823-1828 ◽  
Author(s):  
J.A. del Valle ◽  
P. Rey ◽  
D. Gesto ◽  
D. Verdera ◽  
Oscar A. Ruano

The effect of friction stir processing (FSP), on the microstructure and mechanical properties of a magnesium alloy AZ61 has been analyzed. This is a widely used wrought magnesium alloy provided in the form of rolled and annealed sheets with a grain size of 45 μm. The FSP was performed with an adequate cooling device in order to increase the heat extraction and reduce the processing temperature. The final microstructure showed a noticeable grain size refinement down to values close to 1.8 μm and an important change in texture. The change in texture favors basal slip during tensile testing leading to an increase of ductility and a decrease in yield stress. The stability of the grain size and the creep behavior at high temperatures were investigated. The optimum conditions for superplastic forming were determined; however, the presence of a large amount of cavities precludes the achievement of high superplastic elongations. Additionally, these results are compared with those obtained by severe hot rolling.


2007 ◽  
Vol 561-565 ◽  
pp. 869-872 ◽  
Author(s):  
Małgorzata Lewandowska ◽  
Kinga Wawer

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.


2008 ◽  
Vol 584-586 ◽  
pp. 777-782 ◽  
Author(s):  
Krzysztof Topolski ◽  
Halina Garbacz ◽  
Krzysztof Jan Kurzydlowski

The potential application range of coarse-grained commercial purity titanium is limited by its low mechanical properties. A reduction of the grain size of titanium leads to a significant increase in its strength and hardness. This paper is concerned with application of hydrostatic extrusion (HE) for fabrication nano-grained titanium. In the present study titanium rods were subjected to hydrostatic extrusion with the aim to reduce the grain size to the nano-metric scale and thereby improve the mechanical properties. The obtained material can be an equivalent and compete with the commonly used Ti6Al4V alloy. The results were compared with those other SPD techniques reported in the literature and refered to Hall-Petch relationship.


2020 ◽  
Vol 321 ◽  
pp. 03018
Author(s):  
Amine HATTAL ◽  
Madjid DJEMAI ◽  
Jean Jacques FOUCHET ◽  
Thierry CHAUVEAU ◽  
Brigitte BACROIX ◽  
...  

Additive manufactured Ti6Al4V reinforced with nano yttria-zirconia (nYSZ) parts were fabricated using selective laser melting technology (SLM). The as-received Ti6Al4V powder and two powder mixtures of Ti6Al4V mixed with several nYSZ contents (1wt% and 2.5wt%) were prepared and then SLM processed. Parts were further subjected to a stress relief heat treatment. Besides, hot isostatic pressure (HIP) was used in order to eliminate residual porosities. The pycnometer-based technique was used to measure the mass density. XRD and EBSD analysis were performed to investigate the influence of nYSZ additions on the microstructure and subsequent mechanical properties via microhardness and compression tests. It was found that addition of nYSZ increases the density of the reinforced parts and produces a fine α martensite phase. Besides, the grain size was refined compared to that of heat treated Ti6Al4V. As a consequence, a significant increase in both the hardness and the compressive strength for the reinforced Ti6Al4V were obtained while the elongation to failure was kept. These improved mechanical properties are discussed in relation to the effect of nYSZ addition, which includes latice distortions and strengthening from grain size refinement and/or α formation.


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