Compatibility summary
You will need a travel adapter in Brazil; plug types used there differ from Australia. Voltage differs by more than 20% — a voltage converter may be needed for some appliances.
Plug comparison
Australia plug types: I
Brazil plug types: C N
There is no common plug type between Australia (I) and Brazil (C N). You need a travel adapter.
Voltage comparison
Australia: 230V, 50Hz
Brazil: 127V, 60Hz
Voltage converter recommended (Australia 230V vs Brazil 127V).