Using　the　experimental　method,　the　discretized　2A10　aluminum　alloy　rivet　specimens　were　obtained　by　controlling　the　depression　amount　of　the　punch,　and　the　microstructure　evolution　of　rivet　head　as　well　as　the　initiation　and　expansion　processes　of　the　adiabatic　shear　band　were　studied.　The　results　show　that　the　difference　of　deformation　in　different　areas　of　the　rivet　head　is　large,　the　initial　deformation　of　the　central　area　and　the　diagonal　area　is　serious,　and　the　shear　band　is　firstly　initiated　in　the　central　area　and　the　diagonal　area,　but　the　initiation　of　primary　and　secondary　shear　bands　are　not　synchronized.　The　main　shear　band　appears　earlier　and　gradually　expands　to　a　parabolic　morphology.　The　secondary　shear　band　disappears　gradually,　and　some　scattered　shear　bands　appear　in　the　lateral　deformation　area.　As　the　depression　amount　increases,　the　main　shear　band　becomes　clearer,　the　width　increases,　the　in-band　grains　break　seriously　which　are　elongated　along　the　direction　of　the　shear　band　with　blurry　grain　boundary.　The　main　shear　band　is　the　most　obvious　when　the　depression　amount　reaches　to　82.12%,　while　the　cracks　do　not　appear　in　rivet　head.　©　2020,　Editorial　Board　of　Journal　of　Plasticity　Engineering.　All　right　reserved.