Interfacial Evolution of WC-Co/AISI 304L Diffusion Bonded Joint Obtained by Flash SPS Technique

In this work, WC-Co cermet was successfully joined to AISI 304L stainless steel using flash spark plasma sintering (FSPS) technique under a constant load of 5 MPa with ultra-rapid holding times. The results revealed that increasing the holding time to 12s resulted in massive interfacial deformations accompanied with an important diffusion activity of Co, Ni and Fe across the interface. Toughness measurement of WC-Co cermet at the vicinity of the bonding interface was assessed using Vickers indentation fracture (VIF) method. The results revealed that the mechanical properties of the bonded joints deteriorated with increasing holding time, leading to increased brittleness. This outcome was observed despite the significant inter-diffusion that occurred between the WC-Co cermet and the constituents of the 304L steel