The materials under consideration are binary
aluminium-copper alloys (10 at% to 90.3 at%Cu) produced by HF melting
and RF magnetron sputtering. The resulting micro structures have been
observed by standard metallographic techniques, X-ray powder diffraction,
scanning electron microscopy and transmission electron microscopy. Vickers
microhardness of bulk Al–Cu alloys reaches a maximum of 1800 MPa at
70.16 at%Cu. An unexpected metastable $\theta '$ phase has been observed
within aluminium grain in Al-37 at%Cu.
The mechanical properties of a family of homogeneous Al$_{1-x}$Cux (0
< x < 0.92) thin films made by radiofrequency (13.56 MHz) cathodic
magnetron sputtering from composite Al–Cu targets have been investigated.
The as-deposited microstructures for all film compositions consisted of a
mixture of the two expected face-centred-cubic (fcc) Al solid solution and
tetragonal θ (Al2Cu) phases. The microhardness regularly
increases and the grain size decreases both with copper concentration. This
phenomenon of significant mechanical strengthening of aluminium by means of
copper is essentially due to a combination between solid solution effects
and grain size refinement.
This paper reports some structural features of different Al–Cu alloys
prepared by HF melting and RF magnetron on glass substrate sputtering.