Evolution of the second phase particles during the heating-up process of solution treatment of Al–Zn–Mg–Cu alloy

2015 ◽  
Vol 641 ◽  
pp. 237-241 ◽  
Author(s):  
Guosheng Peng ◽  
Kanghua Chen ◽  
Songyi Chen ◽  
Huachan Fang
Keyword(s):  
Solution Treatment ◽  
Second Phase ◽  
Cu Alloy ◽  
Second Phase Particles ◽  
Heating Up

scholarly journals Evolution of the Second-Phase Particles and Their Effect on Tensile Fracture Behavior of 2219 Al-xCu Alloys

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 197
Author(s):  
Daofen Xu ◽  
Kanghua Chen ◽  
Yunqiang Chen ◽  
Songyi Chen
Keyword(s):  
Fracture Behavior ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Fracture Initiation ◽  
Tensile Tests ◽  
Tensile Fracture ◽  
Second Phase ◽  
Cu Content ◽  
Second Phase Particles ◽  
Microcrack Propagation

In this study, the continuous evolution of the second-phase particles across as-cast, homogenization, multi-directional forging (MDF), and solution-aging treatment and their effect on tensile fracture behavior of 2219 aluminum alloys with different Cu contents was examined by optical microscopy (OM), scanning electron microscopy (SEM), and tensile tests. The results showed that the microstructure of as-cast 2219 aluminum alloy consisted of the α-Al matrix, Al2Cu coarse phase, and Fe-rich impurity phase. Severe segregation of Cu existed, and eutectic networks can be observed in the ingot. With an increase in Cu content, the eutectic networks became coarsen and thicker. During the complex improved process, the refinement mechanisms were fragmentation, dissolution, and diffusion of Al2Cu particles. Most fine Al2Cu particles were fully dissolved into the matrix and partial coarse particles were still retained after solution-aging treatment. Thus, the elongations of all the samples, undergoing solution treatment followed by water quenching, increased evidently. Then, the elongations decreased slightly due to the increase of precipitates. The fractography analysis of peak aged condition samples indicated that the fracture mode was diverted from a typical inter-granular fracture to a mainly trans-granular fracture with increase in Cu content from 5.56% to 6.52%. Fracture initiation mainly occurred by original microcrack propagation and microvoid nucleation at the coarse constituents.

Investigation of a New Type of Al3Ti-Based Ll2 Alloy With Second Phase Precipitation

1994 ◽  
Vol 364 ◽  
Author(s):  
Gengxiang Hu ◽  
Jian Sun ◽  
Xiaojun Weng ◽  
Tong Li ◽  
Shipu Chen
Keyword(s):  
Single Phase ◽  
Solution Treatment ◽  
Second Phase ◽  
Quaternary Alloys ◽  
Two Phase ◽  
Ti Alloys ◽  
Second Phase Particles ◽  
New Type ◽  
Temperature Aging ◽  
Nb Additions

AbstractSince the L12 structured Al3Ti alloy exists only in a narrow compositional range, further alloying of the single phase Ll2 alloy to improve its property seems hardly successful. Developing two-phase or multiphase Al3Ti alloys may be an effective approach for strengthening and toughening. In this article, a new type of Al3Ti-based alloy which has a Ll2 matrix with precipitates of a second phase is reported. The quaternary alloys based on Al67Mn8Ti25, and modified with Nb additions, consist of an Ll2 matrix and DO22 second phase particles in the annealed state, but the second phase can be dissolved by solution treatment and precipitated during high temperature aging. Remarkable strenghtening and promising compressive ductility were exhibited by the experimental alloy. The influence of composition on the microstructure and properties of the alloys are reported also.

Growth behavior study of second phase particles in a Zr–Sn–Nb–Fe–Cr–Cu alloy

2012 ◽  
Vol 423 (1-3) ◽  
pp. 127-131 ◽  
Author(s):  
B.F. Luan ◽  
L.J. Chai ◽  
J.W. Chen ◽  
M. Zhang ◽  
Q. Liu
Keyword(s):  
Growth Behavior ◽  
Second Phase ◽  
Cu Alloy ◽  
Behavior Study ◽  
Second Phase Particles

Microstructures and Properties of Twin-Roll Casting 7050 Aluminum Alloy Strip

2013 ◽  
Vol 652-654 ◽  
pp. 2397-2403 ◽  
Author(s):  
Chun Fu Li ◽  
Hong Bin Wang ◽  
Fan Lei Meng ◽  
Hong Yang Zhao
Keyword(s):  
Electron Microscopy ◽  
Aluminum Alloy ◽  
Solution Treatment ◽  
Second Phase ◽  
Alloy Strip ◽  
Twin Roll Casting ◽  
Roll Casting ◽  
7050 Aluminum Alloy ◽  
Second Phase Particles ◽  
Twin Roll

In this study, 7050 aluminum alloy strip was produced using the twin-roll casting technique. Microstructures and properties of the cast-rolling 7050 aluminum alloy were investigated by means of optical microscope (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and Vickers hardness test. The results indicate that microstructures of cast-rolling 7050 alloy strip are inhomogeneous on the cross section. From the edge to the center, the size of grain decreases gradually and becomes more homogeneous, showing a transition from dendrite grains to equiaxed grains. There are undissolved second phase particles in grains and at grain boundaries. And the dendrite grains and second phase particles can be reduced by solution treatment, and the hardness of the cast-rolling strip can be improved by aging treatment.

scholarly journals Effects of Excessive Zr Content and Ultrasonic Treatment on Microstructure and Mechanical Properties of Al-Zn-Mg-Cu Alloy

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 632
Author(s):  
Cheng Li ◽  
Shusen Wu ◽  
Shulin Lü ◽  
Jianyu Li ◽  
Longfei Liu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Ultrasonic Vibration ◽  
Ultrasonic Treatment ◽  
Second Phase ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Microstructure And Mechanical Properties ◽  
Second Phase Particles ◽  
Properties Of Materials

The Zr element is one of the important grain refiners for 7xxx series Al-Zn-Mg-Cu alloys, but the effect of Zr content more than 0.15 wt.% needs to be deeply investigated under the action of ultrasonic vibration. In this study, the effects of Zr contents (0.1 to 0.25 wt.%) on microstructure and mechanical properties of Al-Zn-Mg-Cu alloy were studied. The results showed that Zr element could refine grains, but when the Zr content was greater than 0.15 wt.%, the grain size was not uniform, the number of second phase particles increased, and the segregation of components became more serious. It was found that after ultrasonic treatment, the grain-size inhomogeneity was greatly improved, and the Zr content could be added up to 0.2 wt.%. When the Zr content is equal or lower than 0.2 wt.%, ultrasonic treatment can effectively improve the mechanical properties of materials by refining grains and weakening segregation. However, when the Zr content is up to 0.25 wt.%, the effect is getting worse.

Polishing process effect on the image of dispersed precipitates

1984 ◽  
Vol 42 ◽  
pp. 534-535
Author(s):  
C.T. Hu ◽  
C.W. Allen
Keyword(s):  
Matrix Material ◽  
Specimen Preparation ◽  
Second Phase ◽  
Precipitate Particle ◽  
Polishing Process ◽  
Second Phase Particles ◽  
The Matrix ◽  
Surface Profiles ◽  
Thinning Process

One important problem in determination of precipitate particle size is the effect of preferential thinning during TEM specimen preparation. Figure 1a schematically represents the original polydispersed Ni3Al precipitates in the Ni rich matrix. The three possible type surface profiles of TEM specimens, which result after electrolytic thinning process are illustrated in Figure 1b. c. & d. These various surface profiles could be produced by using different polishing electrolytes and conditions (i.e. temperature and electric current). The matrix-preferential-etching process causes the matrix material to be attacked much more rapidly than the second phase particles. Figure 1b indicated the result. The nonpreferential and precipitate-preferential-etching results are shown in Figures 1c and 1d respectively.

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