ANALYSIS OF INFILTRATION PROCESSES DURING THE FABRICATION OF SiCw/Al COMPOSITE BY SQUEEZE CASTING METHOD

The infiltration processes of melt aluminium alloy into SiC whisker pre-form were analyzed during the fabrication of SiCw/Al composite by squeeze casting method.The infiltration pressure was calculated to be less than 2 MPa.The compressive tests of the SiC whisker preforms with different whisker volume fraction were carried out in the condition similar to that of the infiltration processes,and the experimental results showed that with the increase of the fabrication prefssure,the preform was compressed and so the volume fraction of whisker of the preform was increased.Based on the analysis of the fabrication processes,it was considered that it needs a period of time for the infiltration processes to be finished so that the preforms were compressed before they were infiltrated by melt aluminium when the fabrication pressure reached the maximum value,and therefore the volume fraction of whisker of preforms was increased.When the pressing speed was very high, the volume fraction of whisker of the SiCw/Al composite was mainly decided by the whisker volume fraetion of preform and the fabrication pressure.