摘要
High temperature in diffusion bonding(DB)process severely deteriorates the performance of zirconium(Zr)R60702 in extreme chemical environment.Therefore,it is important to reduce the DB temperature of Zr R60702.In this work,low-temperature diffusion bonding of Zr R60702 at 750°C is realized by 0.3 wt%hydrogen addition while 900°C is required in DB process for unhydrogenated Zr R60702.The shear strength of the hydrogenated joint bonded at 750°C reaches 388 MPa,which is 117.98%higher than that of the unhydrogenated joint bonded at 750°C and equal to that of the unhydrogenated joint bonded at 900°C.The effects of hydrogen addition in Zr R60702 on the microstructure evolution,phase transformation temperature,interatomic bonding and self-diffusion coefficient of Zr atoms are investigated in detail.The results show that the optimized DB properties can be attributed to the improvements of its grain boundary diffusion,plasticity and self-diffusion coefficient of Zr atoms.
基金
supported by the NSFC-Liaoning Province United Foundation(U1908229)
the National Natural Science Foundation of China(51875350)
the Program of Shanghai Academic Research Leader(22XD1421600).
