scholarly journals Macrosegregation behavior of solute Cu in the solidifying Al-Cu alloys in super-gravity field

2018 ◽  
Vol 115 (5) ◽  
pp. 506
Author(s):  
Yuhou Yang ◽  
Bo Song ◽  
Zhanbing Yang ◽  
Jin Cheng ◽  
Gaoyang Song ◽  
...  
Keyword(s):  
Gravity Field ◽  
Solute Content ◽  
Negative Segregation ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Channel Segregation ◽  
Bottom Position ◽  
Gravity Coefficient ◽  
Rich Liquid ◽  
Solidification Stage

In this research, super gravity field was introduced to investigate the macrosegregation behavior of solute Cu in Al-Cu alloys in super gravity field systematically. And the macrosegregation mechanism was also explored by well-designed experiments. When Al-Cu alloys were solidified in super gravity field, the macrosegregation of solute Cu was generated and the solute Cu increases along the direction of super gravity field. The macrosegregation becomes severer with the increasing gravity coefficient and the solute content. When the Al-4.5wt%Cu alloy was solidified in super gravity field of G = 800, the copper content at the bottom position increases up to 8.48 wt% and that at the up position decreases to only 2.58 wt%, resulting in the positive segregation at the bottom and the negative segregation at the top of the sample. The segregation mechanisms are that solute-rich regions, which have a larger density than the main liquid, sediment toward the bottom of the sample under the effect of super gravity, and at the final solidification stage, super gravity can drive the residual solute-rich liquid to flow toward the bottom of the sample along the dendrite space (channel), which formed the super gravity channel segregation.

Plastic deformation of θ ' in Al-4%Cu alloy

1978 ◽  
Vol 36 (1) ◽  
pp. 576-577
Author(s):  
Shrikant P. Bhat
Keyword(s):  
Deformation Behavior ◽  
Room Temperature ◽  
Electron Microscopic Observation ◽  
Bulk Alloy ◽  
Electron Microscopic ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Orowan Mechanism ◽  
The Subject ◽  
Cyclic Straining

deformation behavior of Al-Cu alloys aged to contain θ ' has been the subject of many investigations (e.g., Ref. 1-5). Since θ ' is strong and hard, dislocations bypass θ ' plates (Orowan mechanism) at low strains. However, at high strains the partially coherent θ ' plates are probably sheared, although the mechanism is complex, depending on the form of deformation. Particularly, the cyclic straining of the bulk alloy is known to produce gross bends and twists of θ '. However, no detailed investigation of the deformation of θ ' has yet been reported; moreover, Calabrese and Laird interpreted the deformation of θ ' as largely being elastic.During an investigation of high temperature cyclic deformation, the detailed electron-microscopic observation revealed that, under reversed straining conditions, θ ' particles are severely distorted--bent and twisted depending on the local matrix constraint. A typical electronmicrograph, showing the twist is shown in Fig. 1. In order to establish whether the deformation is elastic or plastic, a sample from a specimen cycled at room temperature was heated inside the microscope and the results are presented in a series of micrographs (Fig. 2a-e).

Researched on the Corrosion Resistance of Ni-Cr-Mo-Cu Alloy to Aqueous Change with the APF in Regular Way: an Approach of Quantum Electrochemistry

2011 ◽  
Vol 55-57 ◽  
pp. 378-381
Author(s):  
Li Hua Pan ◽  
Rui Cheng Yang
Keyword(s):  
Corrosion Resistance ◽  
Cathodic Current ◽  
Cu Alloy ◽  
Cu Alloys

The corrosion resistance of Ni-Cr-Mo-Cu alloys designed by formula APF=4Cr/(2Mo+Cu) to aqueous depend on the APF is investigated. The cathodic current of corrosion reactions was expressed as the quantum electrochemical equation. It is discussed that the APF controls the corrosion resistance to aqueous.

scholarly journals Kinetic Monte Carlo Simulation of Clustering in an Al-Mg-Si-Cu Alloy

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4523
Author(s):  
Qilu Ye ◽  
Jianxin Wu ◽  
Jiqing Zhao ◽  
Gang Yang ◽  
Bin Yang
Keyword(s):  
Activation Energy ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Kinetic Monte Carlo ◽  
Complex Interaction ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Simulation Results ◽  
Small Clusters ◽  
First Time

The mechanism of the clustering in Al-Mg-Si-Cu alloys has been a long-standing controversial issue. Here, for the first time, the mechanism of the clustering in the alloy was investigated by a Kinetic Monte Carlo (KMC) approach. In addition, reversion aging (RA) was carried out to evaluate the simulation results. The results showed that many small-size clusters formed rapidly in the early stages of aging. With the prolongation of aging time, the clusters merged and grew. The small clusters formed at the beginning of aging in Al-Mg-Si-Cu alloy were caused by initial vacancies (quenching vacancies). The merging and decomposition of the clusters were mainly caused by the capturing of vacancies, and the clusters had a probability to decompose before reaching a stable size. After repeated merging and decomposition, the clusters reach stability. During RA, the complex interaction between the cluster merging and decomposition leaded to the partial irregular change of the hardness reduction and activation energy.

Structural state and thermodynamic stability of Al–Cu alloys

2020 ◽  
Vol 34 (08) ◽  
pp. 2050057
Author(s):  
Nataliia Filonenko
Keyword(s):  
Thermodynamic Stability ◽  
Crystallization Process ◽  
Heating Temperature ◽  
Liquidus Line ◽  
Primary Aluminum ◽  
Complete Suppression ◽  
Cu Alloy ◽  
Cu Alloys ◽  
High Temperature Expansion ◽  
First Time

It is known that processes occurring in binary system melts affect the crystallization process and the phase composition of alloys. To predict these processes, we should determine the region of thermodynamic stability of the melt. In this paper, the structural properties of hypoeutectic and hypereutectic alloys in Al–Cu system are studied depending on the heating temperature above the liquidus line and aftercooling rate. It is shown that overheating of Al–Cu melts to 150 K above the liquidus line and further cooling leads to complete suppression of the process of formation of primary aluminum crystals in hypoeutectic alloys and [Formula: see text] phase in hypereutectic alloys. For the first time, by accounting in Gibbs energy of binary Al–Cu alloy for the first degree approximation of high-temperature expansion of thermodynamic potential, the dependence of temperature of line of the melt thermodynamic stability on copper content in alloy is obtained.

scholarly journals On the Role of Dilute Solute Additions on Growth Restriction in Binary Copper Alloys

2020 ◽  
Vol 9 (6) ◽  
pp. 825-832
Author(s):  
M. J. Balart ◽  
F. Gao ◽  
J. B. Patel ◽  
F. Miani
Keyword(s):  
Copper Alloys ◽  
Growth Restriction ◽  
Restriction Factor ◽  
Modeling Framework ◽  
Solute Content ◽  
Grain Length ◽  
Cu Alloys ◽  
Acta Mater ◽  
Columnar Grain

AbstractThe effect of dilute solute additions on growth restriction in binary Cu alloys has been assessed at different degrees of superheat. Columnar grain length values from Northcott’s work (Northcott in J Inst Metals 62:101-136, 1938) for binary Cu alloys were plotted against the corresponding undercooling parameter (P), the reciprocal of the conventional (Qconv.) and true (Qtrue) growth restriction factor (Schmid-Fetzer and Kozlov in Acta Mater 59(15):6133-6144, 2011) values. It was found that there was no correlation between the columnar grain length values and P, 1/Qconv. and 1/Qtrue values for different solutes and cast at the same degree of superheat. Unlike P, Qconv., and Qtrue values, the heuristic growth restriction parameter (β) (Fan et al. in Acta Mater 152, 248-257, 2018) modeling framework in conjunction with the critical solute content (C*) for growth restriction fitted well to binary Cu alloys.

scholarly journals Study on the wetting interface of Zr–Cu alloys on the SiC ceramic surface

RSC Advances ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 3487-3492 ◽  
Author(s):  
Bofang Zhou ◽  
Jinfeng Wang ◽  
Keqin Feng
Keyword(s):  
Working Conditions ◽  
Filler Metal ◽  
Ceramic Surface ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Sic Ceramic ◽  
New Type ◽  
Special Working

A Zr–Cu alloy, as a new type of filler metal, is proposed for brazing SiC ceramic under special working conditions.

The Dependence of the Corrosion Resistance of Ni-Cr-Mo-Cu Alloy to HCL Solution on the 4Cr/ (2Mo+Cu)

2011 ◽  
Vol 194-196 ◽  
pp. 1920-1923
Author(s):  
Pan Li Hua ◽  
Rui Cheng Yang
Keyword(s):  
Corrosion Resistance ◽  
Kinetic Parameters ◽  
Empirical Formula ◽  
Corrosion Process ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Kinetics Of ◽  
Hcl Solution

The kinetics of corrosion process on five Ni—Cr—Mo—Cu alloys designed by the empirical formula APF=4Cr/ (2Mo+Cu) in HCl solution have been investigated at the concentration range from 0.002mol/cm3to 0.012 mol/cm3and 20°C. It is developed that the kinetic parameters and the dependence of the corrosion resistance on the APF have discussed.

Structure and Property of Nickel-Modified Ultrahigh Strength Al-Zn-Mg-Cu Alloy by Spray Forming

2007 ◽  
Vol 546-549 ◽  
pp. 871-876
Author(s):  
Zhen Liang Li ◽  
Jian Xin Xie ◽  
Wei Chen ◽  
Jing Zhai ◽  
Hui Ping Ren ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Spray Deposition ◽  
Spray Forming ◽  
Homogeneous Distribution ◽  
Structure And Property ◽  
Ultrahigh Strength ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Ni Alloy ◽  
Properties Of Materials

Six kinds of Al-Zn-Mg-Cu alloys, modified with nickel and zirconium, have been produced by rapid solidification using spray deposition(the Osprey process). The effect of nickel on the structures, mechanical properties of ultrahigh strength aluminium alloy is studied, and the probable maximum of mechanical properties is predicted. There are three nickel-rich phases, Al3Ni2, Al7Cu4Ni and MgNi2, forming in 1%Ni alloy, its ultimate tensile strength(UTS) increased with increasing extrusion ratios significantly while maintaining high levels of ductility, Futhermore, the extruded bars show enhancing more clearly than extruded plates in UTS and ductility. The content of Ni should decreased with increasing of Zn and Zr, and the highest properties(UTS=832MPa, Elongation=7.5%)are attained in 0.20Zr＋0.30Ni (wt%)alloy. In addition, the size, the shape and the homogeneous distribution of zirconium-rich phase produced in solidification is the key to effecting the mechanical properties of materials when Zr content is 0.2~0.5％.

Mechanical and Corrosion Behaviors of the Casting Al-Cu Alloy Modified by Nano-Scale PrxOy and LaxOy

2015 ◽  
Vol 1120-1121 ◽  
pp. 1053-1058
Author(s):  
Hai Long Zhao ◽  
Wen Zhang ◽  
Chun Lin Zhang ◽  
Da Qian Sun ◽  
Xu Wang
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Fracture Strain ◽  
Electrochemical Corrosion ◽  
Nano Scale ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Electrochemical Corrosion Behavior ◽  
Corrosion Behaviors ◽  
Mechanical Properties And Corrosion

The mechanical properties and corrosion behaviors of the casting Al-Cu alloys were investigated. The proportion of the two modifiers (PrxOy and LaxOy) has effects on the mechanical properties and the electrochemical corrosion behavior of the casting Al-Cu alloy. The ultimate true tensile strength of the Al-Cu alloy modified only by LaxOy is the highest (616.0 MPa). The fracture strain of the Al-Cu alloy modified by PrxOy and LaxOy is the highest (12.3%). The Al-Cu alloy modified by PrxOy has better corrosion resistance than any other Al-Cu alloy. The prominent mechanical properties should be attributed to the finer crystal grains and more homogeneously distributed nano-scale phase precipitates. The existence of continuous and compact protective Al2O3 and RE-O films enhanced the corrosion resistance of the modified Al-Cu alloy during the corrosion process.

Aging Behavior of Al-Cu Alloys Produced by Melt Extrusion Process

2006 ◽  
Vol 116-117 ◽  
pp. 550-553
Author(s):  
Byoung Soo Lee ◽  
Dae Heon Joo ◽  
Hoon Cho ◽  
Hyung Ho Jo ◽  
Myung Ho Kim
Keyword(s):  
Mechanical Properties ◽  
Extrusion Process ◽  
Semisolid State ◽  
Aging Behavior ◽  
Melt Extrusion ◽  
Cu Alloy ◽  
Cu Alloys ◽  
Metallic Melt ◽  
Mean Grain Size ◽  
The Mean

Melt extrusion is a new fabrication process with the characteristics of both casting and extrusion. In this process, a metallic melt which is poured and solidified up to semisolid state in the container can be directly extruded through the die exit to form a product of bar shape without other intermediate processes. The aging behavior of Al-Cu alloys in the semisolid state was investigated. And the microstructure and mechanical properties of the melt extruded Al-Cu alloy bar were measured and its characteristics are compared with those of a hot extruded Al-Cu alloy bar. Al-Cu alloys were successfully extruded after squeezing out of liquid during melt extrusion with smaller force compared to the solid extrusion. Al-Cu alloys bar with the mean grain size of up to 200 μm was fabricated by melt extrusion process. And the mechanical properties of the melt extruded Al-Cu alloy bar were improved after the T6 treatment.

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