Abstract:
The present invention relates to a novel process for forming metal matrix composite bodies. Particularly, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with a rigidized filler material or a rigidized preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the rigidized filler material or rigidized preform. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum. In one embodiment of the invention, a filler material or preform can be rigidized by firing and at least partially sintering the filler material so as to provide a three-dimensionally interconnected network of sintered filler material. In another embodiment of the invention, a refractory material mixture is contacted against an exterior surface of a preform or filler material and at least at some point during the process becomes structurally supportive.
Abstract:
The present invention relates to a novel process for forming metal matrix composite bodies. Specifically, in a particularly preferred embodiment for making metal matrix composite bodies by a spontaneous infiltration technique, an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere are in communication with a rigidized filler material or a rigidized preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the rigidized filler material or riigidized preform. A structural refractory material which holds the preform is made by forming a first precursor to the supportive structural refractory material and subsequently causing the precursor to become a rigid supportive structural member. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.
Abstract:
The present invention relates to a novel process for forming metal matrix composite bodies by using a reactive barrier material. Particularly, an infiltration enhancer or an infiltration enhancer precursor or an infiltrating atmosphere are in communication with a filler material or a preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform up to the reactive barrier material. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum. Accordingly, shaped metal matrix composite bodies can be produced having superior surface finish.
Abstract:
The present invention relates to a novel process for forming metal matrix composite bodies. Particularly, an infiltration enhancer and/or an infiltration enhancer precursor and/or an infiltrating atmosphere are in communication with a filler material or a preform, at least at some point during the process, which permits molten matrix metal to spontaneously infiltrate the filler material or preform. Such spontaneous infiltration occurs without the requirement for the application of any pressure or vacuum.
Abstract:
A metal matrix composite is formed by contacting a molten matrix alloy with a permeable mass of filler material or preform in the presence of an infiltrating atmosphere. Under these conditions, the molten matrix alloy will spontaneously infiltrate the permeable mass of filler material or preform under normal atmospheric pressures. Once a desired amount of spontaneous infiltration has been achieved, or during the spontaneous infiltration step, the matrix metal which has infiltrated the permeable mass of filler material or preform is directionally solidified. The directionally solidified metal matrix composite may be heated to a temperature in excess of the liquidus temperature of the matrix metal and quenched. This technique allows the production of spontaneously infiltrated metal matrix composites having improved microstructures and properties.