Grain boundary versus transgranular ductile failure |
| |
Authors: | T. Pardoen D. Dumont Y. Brechet |
| |
Affiliation: | a Département des Sciences des Matériaux et des Procédés, Université catholique de Louvain, PCIM, Place Sainte Barbe 2, B-1348 Louvain-la-Neuve, Belgium b Research Center on Microscopic and Nanoscopic Devices and Materials (CERMIN), Université catholique de Louvain, B-1348 Louvain-la-Neuve, Belgium c Pechiney, Centre de Recherches de Voreppe, 725, rue Aristide Bergès, BP27, 38341 Voreppe, France d LTPCM-ENSEEG, Domaine Universitaire de Grenoble BP75, F-38402 Saint Martin d'Heres, France |
| |
Abstract: | The competition between intergranular and intragranular fracture is investigated using a bilayer damage model, which incorporates the relevant microstructural features of aluminium alloys with precipitate free zones (PFZ) nearby the grain boundary. One layer represents the grain behaviour: due to precipitation, it presents a high yield stress and low hardening exponent. The other layer represents the PFZ which has the behaviour of a solid solution: it is much softer but with a much higher strain hardening capacity. In both layers, void growth and coalescence is modelled using an enhanced Gurson-type model incorporating the effects of the void aspect ratio and of the relative void spacing. The effects on the ductility (i) of the flow properties of each zone, (ii) of the relative thickness of the PFZ, and (iii) of the particles spacing and volume fraction in the PFZ are elucidated. Comparisons are made with experimental data. Based on the previous analysis, qualitative understanding of trends in the fracture toughness of aluminium alloys can be gained in order to provide a link with the thermal treatment process. |
| |
Keywords: | A. Fracture mechanisms A. Grain boundaries A. Voids and inclusions B. Constitutive behaviour B. Elastic-plastic porous material |
本文献已被 ScienceDirect 等数据库收录! |
|