Paper SE-ThP7
Structure and Mechanical Properties of Tungsten-Yttrium Based Coatings

Thursday, October 31, 2013, 6:00 pm, Room Hall B

The challenging environment associated with a fusion reactor will require the utilization of advanced materials in order to enable successful development of fusion energy for the future. Tungsten(W)-based materials have been considered for nuclear reactor applications for its outstanding properties such as high melting point, low vapor pressure, high thermal conductivity, and low thermal expansion coefficient. However, pure W exhibits low fracture toughness at all temperatures and a high ductile to brittle transition, which depends on the chemical and microstructure. The present work was focused on the W-Y based alloy coatings grown by sputter-deposition. The sputtering was performed using a W-Y target to fabricate coatings on to MgO(100) substrates. W-Y coatings were made at various growth temperatures (T_s) ranging from room temperature to 500 ^oC. The structural and mechanical properties of the coatings were evaluated as a function of T_s. While the ultimate goal is to investigate the performance of W-Y coatings as a structural material in the next generation nuclear reactors, preliminary results obtained on the crystal structure, composition, stress evolution and mechanical properties of the coatings are presented and discussed.