Casting and tixoextruded A356-T6 aluminum alloy behavior under isothermal and thermomechanical fatigue

Author(s)

Valdinei Ferreira da Silva

• Document type: Doctoral Thesis
• Press: São Carlos.
• Institution: Universidade de São Paulo (USP). Instituto de Física de São Carlos (IFSC/BT)
• Defense date: 2004-08-31

Examining board members

Waldek Wladimir Bose Filho; Arnaldo Homobono Paes de Andrade; José Alexander Araújo; Maurizio Ferrante; José Ricardo Tarpani

• Advisor: Waldek Wladimir Bose Filho

Abstract

Thermal gradients induced in components during service under temperature changes can cause internal stresses and strains. This cyclic thermal behavior can cause crack nucleation and propagation under a process denominated thermomechanical fatigue. Permanent mold casting and tixoextruded A356-T6 aluminum alloy behavior under isothermal and thermomechanical fatigue was study in this work. Isothermal low cycle fatigue tests were performed in temperatures of 120 and 280°C. In-phase and out-of-phase thermomechanical fatigue tests were carried out in temperature range from 120 to 280°C. The tixoextruded material presented better isothermal and thermomechanical fatigue performance due to a globular microstructure and lower porosity level. (AU)