| abstract |
Lightweight, strong, engine valves that incorporate a valve stem made from a refractory monofilament-reinforced, titanium-based metal matrix composite. Advantageously, the composite of the present invention is sufficiently strong so that valve stems incorporating the composite can be hollow for providing significant weight reduction while meeting valve stem strength and stiffness specifications. The valve includes a valve stem comprising a first end, a second end, and EL longitudinal axis extending from the first end to the second end. The valve stem comprises a composite incorporating a titanium-based metal binder matrix and an axially aligned cluster of continuous, refractory monofilaments incorporated in the binder matrix. A valve head is provided at one end of the valve stem, and a valve tip is provided at the other end. The invention also relates to a method of making such valves. The invention further relates to a composite assembly from which such valves may be machined. |