介入支架是心脑血管疾病治疗中的重要植入物，由于脑血管的管径极细且弯曲复杂，目前没有直接介入脑血管的支架，因此血管支架必然朝着尺寸微细化、形状复杂化、性能柔韧化的方向发展，激光微连接被认为是未来细血管支架制造的最佳选择。考虑到焊接接头作为人体植入物的安全性要求，本项目拟开展血管支架用TiNi形状记忆合金的激光微连接及接头生物相容性的研究。通过试验、理论分析和多尺度仿真相结合的研究方法，明确激光微连接物理过程，揭示微连接熔池行为的尺寸效应，探究微连接接头的精细组织、力学完整性和生物相容性，探讨主导微连接力学性能和生物学特性的特征微观组织，完善微连接接头的质量控制理论基础。本项目的实施，有望加深对激光微连接本质的理解和认识，深入掌握熔池行为的尺寸效应和微连接技术对植入材料可能造成的生物体反应，为医疗器械的设计制造提供理论基础，同时为微观尺度下的焊接基本理论的形成提供可靠依据。

Interventional stent is the most important implant for the clinical therapy of cardiovascular disorders. Unfortunately, there is no directly cerebrovascular stent in current because of the ultrafine and sinuous vasculature. Consequently, future stent would be characterized by miniaturized size, complex shape and flexible performance . In this case, laser microjoining is an inevitable choice for the manufacture of cardiovascular stent. Taking the safety demanding of the welded joint as a human implant into account, it intends to study on the laser micro-joining and the joint biocompatibility of TiNi shape memory alloy used for cardiovascular stent in this project. Based on the combined methods of experoments, theoretical analysis and multiscale simulation, the physic process of the laser micro-joining, size effect of the behavior of weld pool, nanostructure, mechanical integrity and biocompatibility of the micro-joint, theoretical basic of quality control of micro-joint will be researched in the project. The implement of this project will promote the understanding of the mechanism of laser micro-joining, size effect of weld pool resulted from size decrease and the biological response caused by implants. It will provide theoretical fundament for fabricating of medical device and enrich the micro-welding metallurgy.