Polycrystalline diamond, PCD, compacts are usually produced by high pressure–high temperature (HP–HT) sintering. This technique always introduces strong internal stresses into the compacts, which may result in self-fragmentation or graphitization of diamond. This may be prevented by a bonding phase and Ti 3 (Si,Ge)C 2 was so investigated. This layered ceramic was produced by Self Propagating High Temperature Synthesis and the product milled. The Ti 3 (Si,Ge)C 2 milled powder was mechanically mixed, in the range 10 to 30wt.%, with 3–6μm diamond powder (MDA, De Beers) and compacted into disks 15mm in diameter and 5mm high. These were sintered at a pressure of 8.0GPa and temperature of 2235K in a Bridgman-type high pressure apparatus. The amount of the bonding phase affected the mechanical properties: Vickers hardness from 20.0 to 60.0GPa and Young's modulus from 200 to 500GPa, with their highest values recorded for 10wt.% Ti 3 (Si,Ge)C 2 . For this composite fracture toughness was 7.0MPam 1/2 , tensile strength 402MPa and friction coefficient 0.08. Scanning and transmission electron microscopy, X-ray and electron diffraction phase analysis were used to examine the composites.