ANALISI COMPONENTI IN ALLUMINIO REALIZZATI PER PROCESSO DI PRESSOFUSIONE IN CAMERA FREDDA

This thesis focuses on the identification and analysis of the main defects found in aluminum alloy components produced through high-pressure die casting. The work was carried out during an internship at Pressofusione Saccense from Piove di Sacco, a company specializing in cold chamber die casting of non-ferrous alloys. Through the examination of production samples and collaboration with the company’s quality control department, several recurring defect types were identified, including porosity, oxide inclusions, delamination after machining, and surface irregularities. Each defect was studied in relation to its origin within the casting process, taking into account variables such as injection speed, mold temperature, alloy composition, and casting geometry. The investigation was supported by metallographic analyses and non-destructive testing when required. The findings show that, although some defects are difficult to eliminate completely, their occurrence can be significantly reduced through careful process optimization, proper mold design, and strict control of raw materials. The results highlight the importance of an integrated approach in order to improve product quality and reduce the rate of defective castings.

ABSTRACT This thesis focuses on the identification and analysis of the main defects found in aluminum alloy components produced through high-pressure die casting. The work was carried out during an internship at Pressofusione Saccense from Piove di Sacco, a company specializing in cold chamber die casting of non-ferrous alloys. Through the examination of production samples and collaboration with the company’s quality control department, several recurring defect types were identified, including porosity, oxide inclusions, delamination after machining, and surface irregularities. Each defect was studied in relation to its origin within the casting process, taking into account variables such as injection speed, mold temperature, alloy composition, and casting geometry. Il presente elaborato si concentra sull’analisi dei principali difetti riscontrabili nei getti in lega di alluminio ottenuti mediante processo di pressocolata. L’indagine, svolta all’interno dell’azienda Pressofusione Saccense di Piove di Sacco, ha previsto un approccio sia osservativo che sperimentale. In particolare, sono stati studiati difetti come la porosità interna, le inclusioni ossidiche, la sfogliatura superficiale e le microcricche, con l’obiettivo di comprenderne le cause principali e i meccanismi di formazione. Per ciascun difetto sono state analizzate le variabili di processo che ne influenzano la comparsa — tra cui parametri di iniezione, condizioni termiche dello stampo, caratteristiche delle leghe utilizzate e geometria dei getti. In seguito sono state proposte possibili soluzioni o strategie di mitigazione; le osservazioni sono state supportate, ove necessario, da analisi metallografiche e controlli non distruttivi. I risultati ottenuti dimostrano come una corretta impostazione dei parametri di pressocolata, unita a un’adeguata progettazione dello stampo e a un attento controllo delle materie prime, possa significativamente ridurre l’incidenza dei difetti, migliorando la qualità e l’affidabilità del prodotto finito.