Influence of cooling rate on the precipitation microstructure in a medium strength Al–Zn–Mg alloy

Deschamps, A.; Texier, G.; Ringeval, S.; Delfaut-Durut, L.

doi:10.1016/j.msea.2008.09.067

Cited by 106 publications

(44 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In heat treatable Al-based alloys precipitation hardening is the dominant strengthening mechanism. For most commonly used alloys such as the Al-Mg-Si (6xxx) and the Al-Zn-Mg-(Cu) (7xxx) alloys, age hardening response can be seriously affected by the cooling rate from solution annealing (e. g. [1][2][3][4][5][6][7][8][9]; and also toughness can be reduced due to reduced cooling rate [10]. To achieve optimal mechanical properties, precipitation during quenching must be fully suppressed, and this is achieved only if the alloy is cooled with the upper critical cooling rate or faster (e. g. [4,8,7]).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Quench sensitivity of Al–Mg–Si alloys: A model for linear cooling and strengthening

Milkereit

Starink

2015

Materials & Design

View full text Add to dashboard Cite

This work studies the quench-induced precipitation during continuous cooling of five Al-Mg-Si alloys over a wide range of cooling rates of 0.05 -2•10 4 K/min using Differential Scanning Calorimetry (DSC), X-ray diffraction, optical-(OM), transmission electron-(TEM) and scanning electron microscopy (SEM) plus hardness testing. The DSC data shows that the cooling reactions are dominated by a high temperature reaction (typically 500 °C down to 380 °C) and a lower temperature reaction (380 °C down to 250 °C), and the microstructural analysis shows they are Mg2Si phase formation and B' phase precipitation, respectively. A new, physically-based model is designed to model the precipitation during the quenching as well as the strength after cooling and after subsequent age hardening. After fitting of parameters, the highly efficient model allows to predict accurately the measured quench sensitivity, the volume fractions of quench induced precipitates, enthalpy changes in the quenched sample and hardness values. Thereby the model can be used to optimise alloy and/or process design by exploiting the full age hardening potential of the alloys choosing the appropriate alloy composition and/ or cooling process. Moreover, the model can be implemented in FEM tools to predict the mechanical properties of complex parts after cooling.

show abstract

Section: Introductionmentioning

confidence: 99%

“…[14,3,15,8,16,17]). In recent years significant improvements were obtained in the in situ investigation of the precipitation processes during cooling of Al alloys from solution annealing through the development of high sensitivity in-situ DSC techniques [18][19][20][21].…”

Section: Introductionmentioning

confidence: 99%

Quench sensitivity of Al–Mg–Si alloys: A model for linear cooling and strengthening

Milkereit

Starink

2015

Materials & Design

View full text Add to dashboard Cite

show abstract

“…For  phase equilibrium alloys, the actual nucleation modes (13)(14)(15)(16)(17)(18)(19) and precipitation mechanisms of the Al-Zn-Mg alloys are determined by the process and quench conditions and any heterogeneities of constituent phases, dispersoids, and grain or subgrain boundaries that may be present. With dependence on quench conditions from supersaturated solid solution, there appear to be the following three possible precipitation reactions (14): (1) solid solution  , (2) solid solution  GP, and (3) solid solution  ή  .…”

Section: Hardening Precipitates In Al-zn-mg-(cu) 7xxx Alloys and The mentioning

confidence: 99%

“…The CCT curves (with their superposed rates of cooling) clearly describe relationships of cooling and microstructure. Calculated times for start of precipitation of GP solute-rich clusters (7,12,(15)(16)(17)(18)(19) appear to follow the concentration of Mg such that the low Mg alloy 7020 has longer periods and high Mg alloy 7039 has short periods. The temperatures of the nose of TTT C-curves and the CCT quench rates required for avoidance of initiating GP or metastable phases appear to increase with the total Zn + Mg solute content of these alloys (see table 5), and the higher Cu content of 7075 appears to provide temperature stability to the η phase of 7075.…”

Section: Jmatpro Time-temperature-transformation and Continuous-coolimentioning

confidence: 99%

“…Similarly, the impurity element Cr and Mn elements that are present in AlCrMgMn and AlFeMn are Mgcompetitors to the MgZn 2 for the 7020 composition. Therefore, under some conditions of processing, Cr and Mn-containing precipitates may have some deleterious effects that lower strength rather than mitigate corrosion or control grain recrystallization or the morphology of Febased constituent phases (16)(17)(18)(19).…”

Section: T Plot Is = -S (See Equations 14 and A2) The Curvature Is mentioning

confidence: 99%

See 1 more Smart Citation

Computational Thermodynamics Characterization of 7075, 7039, and 7020 Aluminum Alloys Using JMatPro

Chinella¹,

Guo²

2011

View full text Add to dashboard Cite

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, ARL-TR-5660 SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR'S ACRONYM(S) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution is unlimited. SUPPLEMENTARY NOTES* Sente Software Ltd., Surrey Technology Centre, 40 Occam Rd., Guildford GU2 7YG, UK ABSTRACTThermodynamics-dependent microstructure, phase, and physical model predictions of material characteristics are demonstrated for aluminum alloys 7020 (Al-4.5Zn-1.2Mg), 7039 (Al-4.0Zn-2.8Mg), and 7075 (Al-5.6Zn-2.5Mg-1.6Cu) by direct application of Sente Software Ltd.'s Java Materials Program (JMatPro) mesoscale computation materials engineering software. JMatPro reveals phase constitutions as a function of input composition, temperature, and time; with the use of material property databases and physical models, it calculates temperature-dependent physical and mechanical properties. The JMatPro material property software provides better and more rapid understanding of materials during research, processing, product manufacture, and service. In this report, JMatPro reveals how structural and protection materials may meet design requirements for low cost, fabricability, and durability. With secondary application, the elastic bulk moduli for intermetallic phase inclusions derived from Gibbs energy by JMatPro are used to predict the maximum levels of microscale shear stresses under hydrostatic pressure. With comparison to conditions known to cause incipient spall in 7020 alloy, the levels of microscale shear stress around intermetallic inclusions are shown to equal or exceed the level of Von Mises calculated shear yield strength of 7020 alloy, revealing that deformation may occur during high load spall events, even at the initial stages of compression. iii SUBJECT TERMS

show abstract

X‐ray Diffraction Study on Lattice Constant of Supersaturated Solid Solution for Al Based Binary Alloys and Selected Al‐Zn‐Mg‐Cu Alloys

Li¹,

Xiong²,

Zhang³

et al. 2012

ICAA13: 13th International Conference on Aluminum Alloys

View full text Add to dashboard Cite

Influence of cooling rate on the precipitation microstructure in a medium strength Al–Zn–Mg alloy

Cited by 106 publications

References 18 publications

Quench sensitivity of Al–Mg–Si alloys: A model for linear cooling and strengthening

Quench sensitivity of Al–Mg–Si alloys: A model for linear cooling and strengthening

Computational Thermodynamics Characterization of 7075, 7039, and 7020 Aluminum Alloys Using JMatPro

X‐ray Diffraction Study on Lattice Constant of Supersaturated Solid Solution for Al Based Binary Alloys and Selected Al‐Zn‐Mg‐Cu Alloys

Contact Info

Product

Resources

About