Microstructural characterizations and mechanical properties of diffusion bonded 316H Stainless Steel

The mechanical properties and microstructure of different diffusion bonded trials of 316H Stainless Steel were compared to analyze the correlation between mechanical properties and the microstructure of the bonded material. The results show that the percent coverage of grain growth across the bond interface can be correlated to the ductility and the ultimate tensile strength of the bonded material. This correlation could be used to help identify whether or not a bond is of good quality. Additionally, the effects of bonding temperature and time can be seen on the quality of diffusion bonded 316H Stainless Steel. With an increase in temperature and time, the percent coverage of the bond line increased as well as the ductility of the material. When prioritizing ductility at high temperatures, bonding conditions of 1150°C for one hour at an 8 MPa interface pressure with a three-hour annealing time under vacuum provided the best results.