可靠的多功能化的纳米无铅焊料合金是当今焊料和纳米材料学中的一大研究热点。纳米尺度焊料合金单体的熔点、润湿性、凝固组织、界面反应、金属间化合物和机械性能是研究其结构性能的基本物理指标。本项目拟在基于申请人前期工作基础和课题组自主研发的特殊设备，结合球差透射电镜、K2超高速相机和多物理场耦合原位样品杆，以锡基合金焊料纳米颗粒、纳米线、纳米片为研究对象，在电子显微镜中构建原位纳米实验室，实现在原位多物理场耦合（电/热/力/气氛/液体/时效/电子束）作用下，单个纳米合金焊料在几何形状、尺寸大小、气氛环境和化学成份作为独立参数变化时熔化凝固相变的动态变化过程。获得纳米焊料在不同场作用条件下的原子迁移和物相变化规律，探索纳米焊料合金可焊性参数及纳米焊接中原子尺度的焊接机理。为纳米焊料相关领域的研究提供真实可靠的实验结果和基本物理图像。

Reliable and versatile nanoscale lead-free solder alloys are a hot research topic in today's solders and nanomaterials. The melting point, wettability, solidification microstructure, interfacial reaction, intermetallic compounds and mechanical properties of an individual nanosolder alloy are the basic physical indexes to study their structural properties. This project is to be based on the previous work and the homemade TEM in-situ multiphysics coupling holders. Cs-corrected TEM, K2 ultra-high speed camera and multiphysics coupled in-situ holders are used to synthesize tin-based alloy solder (nano-particles, nanosheets, nanowires) as the research object, the establishment of in-situ nanotechnology laboratories in the electron microscope to achieve in situ multiphysics coupling (electricity / cold / heat / force / atmosphere / liquid / aging / electron beam), a single nano-alloy solder in geometry, size, atmosphere and chemical composition as a separate parameter changes in the melting and solidification of the dynamic change process. Atomic mobility and phase transformation of nanometer solder under different field conditions were obtained, and the soldering parameters of nanometer solder alloy and the welding mechanism of nanoscale welding at atomic scale were explored. Provide reliable experimental results and basic physical images for research in the field of nanoscale solder alloy.