Effect Of Recycle Technology And Cleaning Method On Microstructure And Property Of ADC12Scrap Prepared By Solid State Recycling

Aluminum alloy has a very wide range of applications in aerospace, railtransportation, as well as areas of daily life. The problem how to deal withaluminum scrap in the production process has also become the concern of theworld. How to improve the utilization of aluminum and aluminum alloys, torealize recycling of aluminum alloy scrap and to achieve the virtuous circle ofaluminum alloy resource utilization play an important role in the social economy.With traditional remelting recycling methods, the recovery of aluminumscrap is low, the cost is high. In addition, the recycling of aluminum chips isdifficult, because a lot of metal loss due to oxidation, resulting in burning andwaste, and covering flux and refining agent must be added during the remeltingprocess, which bring about harmful gases and poor safety factor. In this study,ADC12aluminum alloy scraps were prepared by solid state, without remeltingprocess, the method is simple, the recycled aluminum alloy has good mechanicalproperties.In this paper, the best technology of the ADC12aluminum alloy scrapsprepared by solid state recycling was studied and the organization evolution ofADC12aluminum alloy prepared by solid state recycling was analyzed. Itshowed that Si particles in ADC12aluminum alloy extrusion organization weresignificantly refined, uniformly distributing in the matrix, compared with Siparticles in as-cast structure, and the higher the temperature of extrusion, themore obviously the grains were refined. The recycled sample of300℃hotpressing and500℃extrusion has good comprehensive mechanical performance,the tensile strength for310MPa, elongation rate for7.9%，hardness value for71HV,compared with the hot extrusion sample using as-cast scraps, the tensile strength of247MPa, elongation rate for10.8%，hardness HV for68HV. It shows that thefracture mechanism is a toughness and brittle fracture of the coexistence ofmixed way through the tensile fracture morphology observation.This paper also studied the cleaning technology of ADC12aluminum alloyscraps polluted by emulsion, through comparing the carbon content under thedifferent cleaning technology process, it shows that surface carbon content ofaluminum alloy scraps using300℃drying after ethanol cleaning is minimum.300℃hot pressing and500℃extrusion is used in the solid state recyclingprocess. Through the analysis of structure and properties of aluminum alloyscraps prepared by solid state recycling under different cleaning methods, therecycled sample of aluminum alloy scraps after300℃drying and ethanolcleaning has the highest tensile strength,300MPa, slightly lower than therecycled sample using scraps without polluted by emulsion,310MPa, higher thanthe hot extrusion sample using as-cast scraps247MPa. It is sure that300℃drying after ethanol cleaning is the best cleaning process, and solid phaserecycling sample has excellent performance.