不同连铸工艺对纯铜杆坯组织性能的影响

Pure copper rod billets were prepared using cold mould up-drawing continuous casting technology, hot mould horizontal continuous casting technology, and sequential cast rolling method (SCR method), and the effect of different processes on microstructure and properties of pure copper rods was studied. The results show that the morphology of the solid-liquid interface determines the direction of heat flow, which in turn determines the direction of grain growth. The structural differences caused by grain growth determine the properties of the rod billets. The solid-liquid interface of polycrystalline copper prepared by cold mould up-drawing casting presents a deep “V” shape, and its longitudinal section structure is coarse columnar crystals parallel to the axis. The structure of polycrystalline copper produced by SCR method is broken equiaxed crystal after rolling. The solid-liquid interface of single crystal copper prepared by hot mould horizontal continuous casting is of “C” type, with a single axial columnar crystal structure. Cold mould up-drawing casting polycrystalline copper and hot mould horizontal continuous casting single crystal copper have good plasticity and conductivity, with elongation of 58% and 60. 67%, and electrical conductivity of 100. 9 %IACS and 102. 6 %IACS, respectively. Polycrystalline copper produced by SCR and polycrystalline copper produced by cold mould up-drawing casting have good strength, with tensile strengths of 307 MPa and 221 MPa, respectively. The hindrance of dislocations and the scattering of free electrons by the interface are the main factors affecting the mechanical and electrical properties of the pure copper rod billets.