Development of a brazing procedure to join W-2Y₂O₃ and W-1TiC PIM materials to Eurofer

The present work proposes a brazing technique to address both the mechanical and metallurgical requirements of joining two different tungsten powder injection moulding materials (W-2Y₂O₃ and W-1TiC) with Eurofer steel. The joining procedure uses pure copper as a filler material and the brazing parameters are 1135 °C for 10 min in a high vacuum furnace. Metallurgical evaluation indicates the achievement, in both cases, of 100% metallic continuity at the interface. The brazing temperature is high enough to activate diffusion phenomena at the interface, giving rise to strong adhesion properties. The mechanical properties are evaluated by shear strength tests with values of 163 ± 55 and 162 ± 6 MPa for W-2Y₂O₃/Eurofer and W-1TiC/Eurofer, respectively. These values are considerably higher than those obtained in previous works using other interlayer materials. The microhardness of these W-base materials is similar to that in the as-received condition, indicating that it was not affected by the brazing process. (topical issue article)