Structural analysis of heat treated automotive cast alloy

• Autorzy: Tillová E. , Chalupová M. , Hurtalová L. , Bonek M. , Dobrzański L. A.
• Języki publikacji: EN

Abstrakty

EN

Purpose: The present study is conducted to investigate and to provide a better understanding of the heat treatment T4 (solution treatment at 505, 515 and 525°C, holding time 2, 4, 8,16 and 32 hours, then quenching in warm water in the range from 40°C and natural aging at room temperature during 24 hours) on the microstructure (morphology of eutectic Si, morphology of intermetallic Fe- and Cu-rich phases) and on mechanical properties (tensile strength and Brinell hardness) of recycled (secondary) AlSi9Cu3 cast alloy. Design/methodology/approach: Metallographic samples were selected from tensile specimens (after testing) and prepared by standard metallographic procedures (wet ground, polished with diamond pastes, finally polished with commercial fine silica slurry (STRUERS OP-U) and etched by Dix-Keller, HNO3 or H2SO4 (standard etching) or HCl (deep etching in order to reveal the three-dimensional morphology of phases). The microstructure was studied using an optical microscope Neophot 32 and SEM observation with EDX analysis using scanning electron microscope VEGA LMU II linked to the energy dispersive X-ray spectroscopy (EDX analyser Brucker Quantax). Hardness measurement was performed by a Brinell hardness tester with a load of 62.5 kp (1 kp = 9.807 N), 2.5 mm diameter ball and a dwell time of 15 s. Findings: The results indicate that increasing solution treatment temperature results in spheroidization of eutectic Si, gradual disintegration of iron rich intermetallic phases on base Al₁₅(FeMn)₃Si₂, dissolution but also melting of intermetallic phases on base Al-Al₂Cu-Si. Optimal solution treatment (515°C/4 hours) most improves mechanical properties. Further increases of solution time, leads to alloy elongations, while both, the tensile strength continuously drop. Practical implications: The present study is a part of larger research project, which was conducted to investigate and to provide a better understanding microstructure, heat treatment and mechanical properties of recycled (secondary) Al-Si cast alloy. Originality/value: The paper contributes to better understanding effect of the T4 heat treatment on the microstructure (morphology of eutectic silicon and intermetallic phases) and mechanical properties (tensile strength and Brinell hardness) of recycled cast alloy.

Słowa kluczowe

EN

aluminium; microstructure; natural aging; eutectic silicon; intermetallic phases

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2011
• Tom: Vol. 47, nr 1
• Strony: 19--25
• Opis fizyczny: Bibliogr. 28 poz., rys.

Twórcy

autor

Tillová E.

• Department of Materials Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic

autor

Chalupová M.

• Department of Materials Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic

autor

Hurtalová L.

• Department of Materials Engineering, University of Žilina, Univerzitná 8215/1, 010 26 Žilina, Slovak Republic

autor

Bonek M.

• Institute of Engineering Materials and Biomaterials, Silesian University of Technology,ul. Konarskiego 18a, 44-100 Gliwice, Poland

autor

Dobrzański L. A.

• Institute of Engineering Materials and Biomaterials, Silesian University of Technology,ul. Konarskiego 18a, 44-100 Gliwice, Poland

Bibliografia

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