Study the effects of squeeze casting parameters on the corrosion behavior of al-Si-4Cu alloy

الملخص EN

This study investigated the effects of squeeze parameters on the properties of squeeze castings and the optimum parameters for producing squeeze castings from Al-Si alloy.

It also compared the properties of the squeeze castings with those of gravity castings.

Squeeze castings were made from Al-Si-4Cu alloy using pressures of 10,15,20,25 and 30 MPa with the alloy poured at 750, 800 and 850oC into a die preheated to 300oC.

Squeeze time was 30s.

The corrosion experiments were performed over a range of elevated pressure, pouring temperature and were carried out in sea water (3.5% NaCl solution).

We have focused to determination of the rate of corrosion and other corrosion characteristics.

Both asgravity cast and squeeze specimens were tested, for comparison.

Corrosion behavior of the materials was assessed by the corrosion potential by potentiostate (polarization) curves.

It was found that for a specific pouring temperature,microstructure of squeeze castings became finer;mechanical properties were increased with increase in pressure to their maximum values.

Compared with gravity casting process, squeeze casting enhanced the mechanical properties; it increased the hardness from Hv 18.083 Kg for gravity castings to a maximum of Hv 35.413 for squeeze castings which constitutes about 50.063 % increase over those of gravity castings.

Although squeeze casting parameter has decreased the corrosion current density (of about 2 μAcm2) when compared to the results of the as-cast samples.