激光表面重熔技术(LSR)可有效提升TC4合金的力学性能，但是LSR过程对TC4试样显微组织和后续拉伸变形机制的影响尚不明确。本文在全马氏体TC4试样的正面和背面进行LSR处理，随后开展拉伸试验，利用透射电镜(TEM)和电子背散射衍射仪(EBSD)进行系统表征，深入探究材料在拉伸过程中的微观结构演变，特别是{10-12}" 孪晶的形成及其分布特征。结果表明：在LSR过程中，激光快速冷却特性显著诱发了残余应力，这一效应不仅促进了特定型马氏体变体的优先生成，还降低了孪晶开启所需的临界分切应力。同时，激光处理时Al元素的蒸发降低了材料的c/a比，减弱了晶格的各向异性，进一步促进了{10-12}孪晶的形成。这些孪晶主要集中于几种具有特定取向的马氏体变体中，这些变体在快速冷却条件下显示出明显的择优生成趋势。

Laser surface remelting (LSR) technology can effectively improve the mechanical properties of TC4 alloy, but the effect of LSR process on the microstructure and subsequent tensile deformation mechanism is still unclear. In this paper, LSR treatment was applied on the front and back of full martensitic TC4 sample, and then tensile test was carried out. Systematic characterization was performed by transmission electron microscopy (TEM) and electron back scattering diffractometer (EBSD), to further explore the microstructure evolution during tensile process, particularly, the formation and distribution of {10-12} twins. The results show that the residual stress is induced significantly by rapid cooling during the LSR process, which not only promotes the preferential formation of specific martensite variants, but also reduces the critical shear stress required for twinning . Simultaneously, the evaporation of Al element during laser treatment reduces the c/a ratio of TC4 alloy, weakens the anisotropy of the crystal lattice, and further promotes the formation of {10-12}twins. These twins are mainly concentrated in several martensite variants with specific orientation, which shows an obvious tendency of preferential formation under the rapid cooling condition.