The 4th International Conference on Matter and Radiation at Extremes (ICMRE 2019)

543 / 2019-03-20 11:50:59

Influence of grain boundary segregation on the dynamic damage evolution in Ni alloy under laser shock loading

grain boundary segregation,laser,spall

Plenary track > High Pressure Physics and Materials Science

The role of grain boundary segregation on damage evolution under laser shock loading has been investigated using both forged and aged two types of nickel alloy targets. The grain boundary Mo segregation is generated in the aged alloy, resulting in an interfacial Mo concentration about 3 times greater than that in the forged alloy. These targets have been shock loaded by direct laser ablation at an intensity of focal spot about 1011W/cm2. The hugoniot elastic limit (HEL) and spall strength were calculated and analyzed from the free surface velocity histories recorded using a line velocity interferometer for any reflections (VISAR) system. It was found that the HEL of grain boundary Mo segregation targets is significantly higher than that of the forged targets. The spall strength for the grain boundary segregation targets varied between 3.73 and 9.39 GPa, and that of the forged targets, between 8.30 and 8.87 GPa. Results of post mortem metallography reveal that the interfacial Mo segregation leads to the creation of more void nucleation sites and promotes the development of intergranular damage.