کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1449165 988693 2008 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Precipitation evolution in Al–Zr and Al–Zr–Ti alloys during aging at 450–600 °C
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
پیش نمایش صفحه اول مقاله
Precipitation evolution in Al–Zr and Al–Zr–Ti alloys during aging at 450–600 °C
چکیده انگلیسی

The transformation of Al3Zr (L12) and Al3(Zr1−xTix) (L12) precipitates to their respective equilibrium D023 structures is investigated in conventionally solidified Al–0.1Zr and Al–0.1Zr–0.1Ti (at.%) alloys aged isothermally at 500 °C or aged isochronally in the range 300–600 °C. Titanium additions delay neither coarsening of the metastable L12 precipitates nor their transformation to the D023 structure. Both alloys overage at the same rate at or above 500 °C, during which spheroidal L12 precipitates transform to disk-shaped D023 precipitates at ca. 200 nm in diameter and 50 nm in thickness, exhibiting a cube-on-cube orientation relationship with the α-Al matrix. The transformation occurs heterogeneously on dislocations because of a large lattice parameter mismatch of the D023 phase with α-Al. The transformation is very sluggish and even at 575 °C coherent L12 precipitates can remain untransformed. Mechanisms of microstructural coarsening and strengthening are discussed with respect to the micrometer-scale dendritic distribution of precipitates.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Acta Materialia - Volume 56, Issue 6, April 2008, Pages 1182–1195
نویسندگان
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