Abstract: A composite material can include: a substrate of a first reaction-bonded silicon carbide (first RB-SiC) material; and a reaction-bonded diamond-retaining silicon carbide (RB-DSiC) layer bonded to a surface of the substrate. In some aspects, the RB-DSiC layer includes diamond particles bonded with a second reaction-bonded silicon carbide (second RB-SiC) material. The diamond particles may be homogeneously distributed through the second RB-SiC or only at the surface thereof. The diamond particles can be in an ordered pattern or un-ordered pattern. For example, a CMP conditioning disc can include the composite material of one of the embodiments.