Abstract: A composition having an empirical formula MB.sub.2-z +N, wherein 0<z<0.10 and M is selected from the group consisting of Zr, Hf and Ti, wherein N is selected from a group consisting of Cu, Au and Ag and wherein the MB.sub.2-z defines a ceramic matrix structure defining a volume with void spaces comprising at least 10 percent of the volume of the matrix structure and the N occupies at least 70 percent, by volume, of the void spaces. A preferred method of making the composition is a two step process: First, ZrB.sub.2 powder (which preferably is slightly enriched in Zr is vacuum hot pressed at a hot pressing temperature of about 2150 degrees C. to create a ceramic matrix having a density of about 68 percent. Second, the ceramic matrix is heated in a pool of copper at a vacuum and at an infiltration temperature of about 1700 degrees C. to permit copper from the pool to infiltrate the ceramic matrix.