由于液固两相的存在，半固态金属成形产生液固分离等，导致成分偏析、组织不均匀等缺陷，影响产品质量，因此需研究半固态金属变形行为，以控制液固两相均匀变形。本项目以锡青铜为研究对象，探讨半固态挤压铜合金液固两相流动行为及均匀变形机制。研究半固态挤压中锡青铜固相粘塑性变形、液相流动和凝固行为，提出半固态挤压过程中固相粘塑性变形和液相流动的协同控制方法，获得液固两相协同流动变形的热力条件；研究Sn元素形态及分布、相结构，掌握Sn析出、扩散和迁移规律，提出Sn偏析控制机制；研究半固态挤压锡青铜组织和性能演变规律，探讨热力条件对组织和性能的作用机制；最终揭示固相粘塑性变形和液相流动协同控制机制，获得Sn偏析控制方法，制备得到组织性能均匀锡青铜挤压件。预期成果为铜合金半固态成形提供理论基础和技术支撑，拓展铜合金产品的深加工技术和方法，拓宽半固态成形在高熔点合金中的应用，丰富和发展半固态金属成形技术的基础。

Because of the existence of liquid-solid phase, liquid segregation was occurred during the semisolid forming, which caused the composition segregation and inhomogeneous microstructure and affected the quality of the products. Therefore, the deformation behavior of semisolid metal forming was studied, then to control the uniform deformation of liquid-solid phase. The tin bronze was chosen as the research object, the flow behavior and uniform deformation of solid-liquid phase of copper alloy during semisolid extrusion process were investigated. The viscoplastic deformation of solid phase, flow behavior and solidification behavior of liquid phase of tin bronze during semisolid extrusion process were analyzed. A method of coordination control for viscoplastic deformation of solid phase and flow behavior of liquid phase during semisolid extrusion was proposed. The thermodynamic conditions for deformation coordination of solid-liquid phase were obtained. The morphology, distribution, and phase structure of Sn element were studied. The rules of precipitation, diffusion, and migration of Sn element were determined. The control mechanism of segregation of Sn element was proposed. The evolution rules of microstructure and properties of tin bronze during semisolid extrusion process were investigated. The mechanism of thermodynamic conditions on microstructure and properties of tin bronze was explored. Finally, the coordination control mechanism of viscoplastic deformation of solid phase and flow behavior of liquid phase was revealed, and the control method of segregation of Sn element was obtained, the tin bronze extrusions with uniform microstructure and performance was prepared. The research results can provide the theoretical basis and technical supports for the copper alloy semisolid forming, expand the technology and method of processing the copper alloy and broaden the application of semisolid forming at high melting point alloys, which can enrich and develop the basic theory of semi-solid metal forming technology.