Fabrication of metal matrix composites by a high-pressure centrifugal infiltration process

A new centrifugal casting process capable of achieving high pressures was developed for fabrication of metal matrix composites. In this process, a mold containing a packed ceramic preform located at an end of an elongated runner was rotated. By controlling the metal level above the preform in the runner to be long and constant throughout the infiltration process, significantly higher pressures were obtained. Infiltration of several packed ceramic preforms was performed to demonstrate the feasibility of the process. Full infiltration was obtained in all the packed ceramic preforms with powder sizes as small as 300 nm. Infiltration pressure studies show high pressures as high as 15 MPa were achieved using a laboratory-scale apparatus. The resulting structure of the infiltrated composites was also studied. The particle distribution, microsegregation in the matrix, and the soundness were reported and discussed. Preliminary results show this technique to have the potential to become a practical fabrication process for metal matrix composites.