In this study, the influence of the grain size and phase composition on damage mechanisms of Ti₃SiC₂-based materials are investigated. Commercially available and self-propagating high-temperature synthesized powders were sintered via spark plasma sintering and hot pressing methods. Materials with different amounts of Ti₃SiC₂ (from 52 to 72 wt%) and various mean grain sizes (from 8 to 20 µm) were characterized by performing bending tests coupled with acoustic emission measurements. It permits to distinguish the involved damage mechanisms and their chronology in MAX phase-based materials. With the increase of the applied stress, damage begins with the onset of delaminations within MAX phase grains, then friction processes occur within previously formed microcracks, and finally (before rupture) new microcracks are generated due to the elasticity mismatch between phases. Increasing Ti₃SiC₂ content and grain size emphasizes the two first damage stages, and finally leads to a more pronounced nonlinear behavior.

在这项研究中，研究了晶粒尺寸和相组成对Ti ₃ SiC ₂基材料损伤机理的影响。通过火花等离子体烧结和热压法烧结可商购的且自蔓延的高温合成粉末。Ti ₃ SiC ₂含量不同的材料通过进行弯曲测试与声发射测量相结合，可以表征（从52到72 wt％）和各种平均晶粒尺寸（从8到20 µm）。它可以区分涉及基于MAX相的材料的损坏机制及其时间顺序。随着施加应力的增加，损坏开始于MAX相晶粒内的分层，然后在先前形成的微裂纹内发生摩擦过程，最后（在断裂之前）由于相之间的弹性失配而产生了新的微裂纹。Ti ₃ SiC ₂含量和晶粒尺寸的增加会突出两个损伤阶段，并最终导致更明显的非线性行为。