A356.2 aluminum alloy has the advantages of low density, high specific strength, high specific stiffness, good corrosion resistance, and good casting performance, and is widely used in automotive aluminum alloyshubUnder casting conditions, the unmodified a356.2 aluminum alloy primary α-al dendrites are thick, the eutectic silicon is distributed in a coarse needle shape, and the silicon phase is brittle, which makes the alloy matrix severely cracked and the plasticity and strength of the alloy Significantly reduced, seriously affecting the mechanical properties of a356.2 aluminum alloy, the next editor will introduceAluminum alloy wheelsmaterial properties.
In the existing technology, rare earth modification has become a hotspot to improve the performance of a356.2. The addition of rare earth can significantly refine the primary α-al phase, play a good role in modifying eutectic silicon, and refine the grain size of as-cast materials. particle size, while significantly inhibiting the occurrence of recrystallization, it can also increase the strength of the aluminum alloy matrix, and can significantly increase the tensile strength and elongation of the casting.
Compared with sodium salt modification and strontium modification, the al-7si-0.35mg alloy after antimony modification has better mechanical properties, and adding an appropriate amount of antimony modification agent to the melt can reduce the inhalation tendency of the melt and improve the alloy's mechanical properties. Impact strength, density, and antimony modification effects have long-term effects.
A method for preparing al-7si-0.35mg-sb aluminum alloy wheel, characterized in that: the chemical elements in the al-si-mg alloy system are proportioned, and the crucible resistance furnace is heated to 250-500°C for melting, Pre-curing, put the high-purity aluminum block and copper-ruthenium alloy into a box-type resistance furnace to preheat to 100-250°C, and then gently put it into the preheated crucible, the recorder will monitor the temperature of the molten aluminum in the crucible furnace in real time , After the aluminum block is completely melted, the temperature is stable at 730-780°C, add a certain proportion of silicon to the molten aluminum for 30 minutes, add al-10sb intermediate alloy, keep 735±5°C after 10-20 minutes, add a certain proportion of pure magnesium, Fully stir for more than 15s, keep for 15min, degas with high-purity nitrogen for 10min, and let stand for 15min.