7475铝合金中η相在E相界面非均匀析出的三维观察

Three dimensional observation of heterogeneous precipitation of η phase on E phase boundary in 7475 aluminum alloy

铝合金中的非均匀析出对其力学性能有较大的影响,本文采用高分辨透射电镜和三维重构技术研究了7475铝合金中η相在E相和铝基体的界面处的非均匀析出,发现η相在E相界面上形核并向铝合金基体中生长,η相在较薄的片状E相的一个平面上形成,E相较厚时,η相易于在片的侧面形成。有较多的η相在棒状E相的界面上形成,但尺寸较小。

The heterogeneous precipitation in aluminum alloys has an important effect on their mechanical properties. In this paper, the heterogeneous precipitation of ηphase on the phase boundary between E phase and matrix in 7475 aluminum alloy was studied by high -resolution transmission electron microscopy and three dimensional reconstruction. It was found that the η phase nucleated on the E phase boundary and grew toward the aluminum matrix. The η phase forms on one plane surface of a thinner plate E phase. When the E phase plate is thick, the η phase precipitates easily on its side face. There are more η phases formed on a virgulate E phase boundary but smaller in size.