B4C/Al cermets and method for making same

摘要

Reactive ceramic-metal compositions are described that include a ceramic phase of at least 70 percent by volume, 95 percent of theoretical density and a metal phase that retains its chemical reactivity with the ceramic phase after the composition has been fully densified. The composition may be heat treated after densification to form additional ceramic phases in a controllable manner. Preferred ceramic metal compositions wherein the metal and ceramic components retain reactivity after densification include boron carbide ceramic and Al or Mg metals. The process employed in forming said compositions requires first forming a sintered porous body of the ceramic material followed by contacting with the metal component, which may be in chip or solid bar form. The system is then heated to the melting point of the metal and a pressure of at least 200 MPa is employed such that the porous body is filled with metal and the composition is substantially fully densified. Subsequent heating reacts the metal with the ceramic to form additional B-C-metal phases as desired.