According to the previous investigation, the dendrites tend to be broken down during the deformation process.

I sent two workers for you that have shown some micro-mechanisms for dendrite fragmentations.

1- Substructure induced dendrite-fragmentation during thermomechanical

processing of as-cast Mg-Sn-Li-Zn alloy (DOI: 10.1016/j.matlet.2021.130690)

2-Throughput study of diffusion along the twin boundaries in Mg-5Sn-0.3Li as-cast alloy and its effect on the homogenization during hot deformation(DOI: 10.1016/j.matlet.2020.128446)