For thermoelectric generators, the individual thermoelectric elements are subjected to significant stresses under in-service conditions, due to thermal cycles, transients, and gradients, as well as thermal expansion mismatch and externally applied mechanical stresses. Most thermoelectric materials are brittle, possessing a low fracture toughness that is typically no more than 1.5 MPa m(1/2) and is often less than 0.5 MPa m(1/2). The combination of the stresses encountered in the device application environment and the materials' low fracture toughness constitute a severe challenge to the viability of thermoelectric generators. The addition of silicon carbide nanoparticles (SiCNP) may provide a route to improving the fracture toughness for a wide range of thermoelectric materials. This study examines the mechanical properties, including elastic modulus, hardness, and fracture toughness for 0-4 vol% SiCNP incorporated into Mg2Si thermoelectric matrices.