Analytically motivated process improvements in continuous metal-matrix composite wire fabrication

A recently developed process allows the production of continuous fiber rein forced metal matrix composite (MMC) wire. Ceramic fiber tows are infiltrate d with metal as the fiber tow is drawn through a pressurized crucible of mo lten metal. Initial production runs allowed fabrication of only limited len gths, due to fiber tow breakage at the crucible entrance. In this paper, a simple analytical model of the fluid mechanics at the entrance to the press urized crucible has been developed to understand and improve the process, a nd to avoid fiber tow breakage at the crucible entry orifice, As a result o f this analysis, subsequent MMC wire production maintains a faster pull spe ed, with corresponding yield lengths of 350 m. The microstructure and prope rties of the MMC wire produced are similar or improved when faster tow pull speeds are employed. (C) 1999 Elsevier Science S.A. All rights reserved.