Products having single phases or solid solutions of the formula M3 X1 Z2 wherein M is a transition metal, X is Si, Al or Ge and Z is B, C or N can be prepared by taking a powdered mixture containing M, X and Z to a temperature of about 1000° C. to about 1800° C., optionally simultaneously under a pressure of about 5 MPa to about 200 MPa. The products so formed have excellent shock resistance, oxidation resistance and machinability. The products may also be present as composites, preferably composites which are in thermal equilibrium with the single phase or solid solutions of the formula M3 X1 Z2.