CAJ | 학술논문

激光冲击表面改性技术是使金属材料表面受惯性和几何约束的被冲击区域局部强烈形变从而强化，具有小光斑逐点累积处理的特点。基于被冲击材料的约束状态，由于激光冲击的超高能量与超高应变率，材料将产生应变屏蔽效应。根据上述特点，通过SEM、TEM、HREM和IFFT综合研究了bcc、fcc和hcp晶型金属材料在激光冲击后的物理冶金学响应及其特点。分析了滑移、孪晶等微结构演变过程及马氏体相变、纳米化现象。讨论了激光冲击形变与常规形变的差异及激光冲击表面形变强化的位错机制。
격광충격표면개성기술시사금속재료표면수관성화궤하약속적피충격구역국부강렬형변종이강화，구유소광반축점루적처리적특점。기우피충격재료적약속상태，유우격광충격적초고능량여초고응변솔，재료장산생응변병폐효응。근거상술특점，통과SEM、TEM、HREM화IFFT종합연구료bcc、fcc화hcp정형금속재료재격광충격후적물리야금학향응급기특점。분석료활이、련정등미결구연변과정급마씨체상변、납미화현상。토론료격광충격형변여상규형변적차이급격광충격표면형변강화적위착궤제。
Laser shock processing is a surface modification technology which allows the shocked region of metallic material surface subjected to inertia and geometry confinements to produce locally drastic deformation and thus to be strengthened , and is characterized by continual and accumulative shocking with small laser spots .Based on the confinement conditions of material to be shocked , the material will offer strain screening effect owing to the ultra-high energy and the super-high strain rate of laser shocking .In the light of these features , the physic-metallurgical response and the characteristics of metallic materials with bcc , fcc and hcp crystalline lattices after laser shocking are synthetically investigated by means of SEM , TEM, HREM and IFFT.The evolution process of slip and twin , martensitic transformation and nano-crystallization are respectively analyzed .The difference between laser shock deformation and conventional deformation and the dislocation mechanism of strengthening materials by laser shock processing are also discussed .