Retrogression and Reaging of AA7075 and AA6013 Aluminum Alloys

Rader, Katherine E.; Carter, Jon T.; Hector, Louis G.; Taleff, Eric M.

doi:10.1007/s11661-020-06133-0

Cited by 5 publications

(1 citation statement)

References 28 publications

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“…Österreicher et al [2] found differences in the differential scanning calorimetry dissolution peak temperatures of hardening precipitates in AA7075 warm-formed at different temperatures; these results indicate different grades of coarsening of the hardening precipitates as a function of warm-forming temperature. Rader et al [10] reported extensive warm tensile test data for AA7075 at various warm-forming temperatures, strain rates, and holding times.…”

Section: Introductionmentioning

confidence: 99%

A Materials Science-Based Approach to Finite Element Simulation of Warm-Forming of Al-Mg-Zn Alloys

Grabner

Österreicher

2022

KEM

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Warm deep-drawing of pre-aged (under-aged) blanks of 7xxx series aluminum alloys (Al-Zn-Mg) at moderate temperatures of roughly 120–230°C is a promising route for producing parts with considerable geometrical complexity, good paint bake hardening response, and, thus, excellent final mechanical properties. Furthermore, oil-based lubricants can be used, eliminating the need for elaborate cleaning routines. However, finite element (FE) simulation of the process is challenging: time-temperature regimes during coupon testing for material cards should closely follow the real conditions in the press because the material undergoes significant changes at warm-forming temperatures, such as recovery and precipitation/coarsening/reversion of hardening phases. When convective heating is used for Nakajima or tensile testing, heating rates are usually too low to adequately represent real process conditions (where inductive or contact heating may be used). Here we present a method for establishing FE material cards and calibrating the GISSMO damage model using miniaturized tensile specimens for a dilatometer with inductive heating. The simulations are compared with warm deep-drawing experiments of pre-aged 7xxx and good agreement of minimum draw temperature for two alloys is achieved. The findings are discussed with regards to transmission electron microscopy investigations and final mechanical properties published earlier. It was found that warm-forming is suitable to produce complex 7xxx parts with high final strength. Conditions in the press can be represented by using miniaturized tensile specimens and inductive heating for calibration of material cards/damage models.

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Section: Introductionmentioning

confidence: 99%