Effect Of Strontium On Microstructure Of 4343 Alloy Sheet By Roll-casting

4343 aluminum alloy is a typical representative of the 4000 series aluminum alloy. It is used as a composite brazing sheet and cladding layer for its low melting point, good flowability and high corrosion resistance. However, the 4343 aluminum alloy has poor cold-rolling property because of its high content of Si, and allays results strip broken during cold-rolling process.In this paper, the effect of additional element strontium on microstructure of 4343 aluminum alloy roll-casting strip is studied, and the influence of the metamorphic treating temperature, incubation time and annealing on the microstructure and property of 4343 alloy sheet by roll-casting is discussed, also a series of results were obtained as follows:(1) Strontium as a new type of metamorphic agent can effectively refine the eutectic Si in the microstructure of 4343 aluminum alloy plate by cast-rolling.(2) Incubation Time and temperature are two important factors for metamorphic treating of 4343 aluminum alloys by strontium. With the increase of the temperature and the time, the eutectic Si particles are smaller.(3) Annealing can effectively change the shape of Si particles,and increase the plasticity of the 4343 aluminum alloy plate.(4) The best metamorphic temperature range of 4343 aluminum alloy is 700℃～720℃ and the time is 20min-40min. The temperature of cast-rolling is 660℃and the annealing temperature is 500℃ for 4 hours.