Contact damage of Ti3SiC2 under Vickers and Hertzian indentations was investigated to understand the energy-dissipation mechanism during the indentation loading. Dissimilar damage modes were revealed at different depths beneath the indent. SEM examinations on the fracture section revealed that under Vickers indentation, grains in the surface layer were crushed into powders, while those in the subsurface layer delaminated, slipped and crushed into fragments, and the grains far from the indent did not deform. Under Hertzian indentation the grains in the damaged zone induced by shear stress slipped, delaminated and fragmentized, while those outside the shear zone did not deform. The damage in the contact region dissipated the energy so that Ti3SiC2 possessed quasi-plasticity. Acoustic emission（AE） counts monitoring of the loading and unloading processes of Hertzian indentation were irreversible in the loading process. Such local energy-dissipation and damage mechanism originated from the nanolayered structure and weak grain boundaries of Ti3SiC2.
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