Fiber tow liquid infiltration

Infiltration occurs due to capillary attraction within the fiber preform and can be undertaken at atmospheric pressure by passing a continuous tow through a bath of molten metal, but is practical only if the molten alloy wets out the carbon fiber [161-168]. A plated coating used to aid wetting must not be too thin otherwise it will be dissolved completely before infiltration has been completed. The application of pressure aids infiltration, but if the preform is compressed too much, then infiltration is prevented, limiting the fiber fraction to about 30 vol%. Composites with Pb alloy matrix can be prepared by an infiltration technique 

The infiltrated tows are assembled into a preform and consolidated by diffusion bonding or hot molding in the two-phase liquid plus solid region. 

A Ti-Cu composite can be achieved by infiltration by heating carbon fiber, Ti wire and Cu ribbon in the region of the Uquidus temperature of the Ti-Cu alloy [171]. 

The Lanxide Corporation (now intellectual property within MSE Inc.) have patented the PRIMEXTM pressureless metal infiltration process and the PRIMEX CASTTM foundry process, which are able to infiltrate ceramic reinforcements with molten metals without application of pressure or vacuum and it is believed that the processes can be used with carbon fiber. 

Liquid phase hot pressing, iiquid phase diffusion bonding or iiquid phase sintering 

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