Nanostructured Al-Al2O3 composite formed in situ during consolidation of ultrafine Al particles by back pressure equal channel angular pressing
W Xu, X Wu, T Honma, SP Ringer, K Xia
ACTA MATERIALIA | PERGAMON-ELSEVIER SCIENCE LTD | Published : 2009
Ultrafine pure Al particles were consolidated into fully dense bulk material using back pressure equal channel angular pressing (BP-ECAP). The consolidation was carried out at 400 °C with a back pressure of 200 MPa. A fully dense Al-Al2O3 composite consisting of mostly nanocrystalline Al and γ-Al2O3, a small fraction of ultrafine Al grains and amorphous alumina was produced after four passes from the freshly formed particles. In contrast, no consolidation was achieved from the aged particles which had been kept for between 18 and 24 months. The formation of the nanostructure was attributed to the interaction between severe shear deformation and in situ oxidation during ECAP. The ultimate str..View full abstract
We are grateful to Mr. F. Meiser and Prof. F. Caruso in the Department of Chemical and Biomolecular Engineering at the University of Melbourne for carrying out TEM on the as received particles, and to Drs. Y. Li and C. Wen at Deakin University for conducting the compressive tests. We also acknowledge the technical, scientific and financial assistance from the NANO-MNRF. This Project was supported by the Australian Research Council with the ARC Centre of Excellence for Design in Light Metals and by the University of Melbourne under the Melbourne Research Grants Scheme.