Al-12 wt.% Si alloy matrix composites reinforced with high volume fraction of Sip were fabricated by squeeze infiltration. The effects of the compacting pressure on the volume fraction of Sip in preforms, and the influences of Sip size and volume fraction on the properties of Al/Sip composites were examined through this study. Si particles were compacted at different pressure of 40-130 MPa followed by sintered at 1000 °C for 7 h to obtain preforms containing 60-70 volume fraction (vol.%) of Sip. The sintered preforms were then infiltrated with Al-12 wt.% Si alloy at 750 °C under a 75 MPa squeeze infiltration pressure. It was found that lower coefficient of thermal expansion (CTE) and smaller density may be obtained with higher Sip volume fraction, yet increasing Sip volume fraction leads to higher amount of porosities in the composites and thus lowers the thermal conductivity (TC) and flexural strength. Besides, with the same Sip volume fraction, coarse Si particles result in higher CTE and TC, while finer Si particles may lower CTE and enhance the flexural strength of the composites effectively. From the results obtained in this study, it is expected that the high volume fraction Sip reinforced Al/Sip composites posses good potential in electronic packaging applications.
- Coefficient of thermal expansion
- Electronic packaging
- Flexural strength
- Squeeze infiltration
- Thermal conductivity