| 摘要 |
<p>A hybrid composite reinforced metal matrix in which the metal is aluminum, aluminum alloy, or a magnesium alloy containing a relatively high percentage of aluminum. In addition to the reinforcement, which is typically alumina, the metal matrix also includes a hardening agent which is at least one intermetallic compound of aluminum with at least one second metal chosen from iron, nickel, titanium, zirconium, cobalt and niobium. The metal matrix optionally also includes graphite as a wear resistant agent. The intermetallic compound(s) can be added as a powder to the metal matrix during formation of the composite, or can be created in the composite by adding the at least one second metal as a powder to the molten metal matrix during composite preparation. If the intermetallic compound is created in the composite, the composite when made initially can be readily machined and is self hardening through repeated heating cycles. The composite finds use in brake parts, such as brake rotors and brake drums as a replacement for the commonly used grey cast iron and exhibits adequate strength and compression properties up to a working temperature of at least about 450ÀC.</p> |
