Cleanliness analysis of molten aluminum for high pressure die casting process

Abstract

In the present work it was made the evaluation at full scale of the cleaning process for aluminum alloy ADC-12Z, for the manufacture of automotive parts by High Pressure Die Casting. This process basically consists of fluxes application in two stages of the melting process, melting furnace and transfer ladle during degassing. The effectiveness of the cleaning and two designs of rotors for degassing, as well as the process in its different stages, were evaluated. They were analyzed using semiquantitative techniques such as the K-Mold and the reduced pressure test (RPT). The main results were as follows: the most effective process for the elimination of inclusions and dissolved hydrogen is degassing with the fluxes application. It is here where the most significant reductions in the contents of both contaminants were obtained. The two rotor designs for degassing were effective in reducing the content of dissolved hydrogen in the alloy, and the most important conclusion, is that the current cleaning processes in the plant are effective and sufficient to obtain metal with the required quality by the internal standards, in terms of the maximum permissible contents of inclusions and dissolved hydrogen.