Title : Mechanical behavior of transition metalscontaining Al-Si-Cu-Mg cast alloy subjected to prolonged thermal exposure
Al-Si-Cu-Mg Cast (354) alloys are extensively used in automotive engine components owing to their outstanding performance after applying the proper heat treatment. Transition elements (Zr, Ni, and Mn) were added in order to avoid the deterioration in mechanical properties of these Al-alloys upon the exposure to elevated temperatures for long times. In this study, static (continuous) and dynamic (interrupted) thermal exposure were employed in order to reveal their effect on tensile and hardness properties of the newly tailored alloys. Results showed that there is deterioration in strength and hardness values; however, the ductility values improved. This reduction in mechanical performance was attributed to coarsening of the strengthening precipitates following the long exposure time. It was obvious that there are no significant variations in the results obtained from the static and dynamic thermal exposure techniques. This finding may allow using the simple static exposure technique widely at laboratory scale to simulate the behavior of the material under dynamic thermal exposure conditions as in the case of the automotive engine components. The deterioration in the mechanical properties was almost flattened after 100h of thermal exposure which may reflect the decelerating coarsening kinetics of strengthening precipitates due to the continuously increasing distance between the precipitates.
Audience take away:
- They will realize the importance of minor additions of certain elements in making Al-alloys suitable for elevated temperature applications and thus overcome the problems associated with utilizing Al-alloys in applications such as: automotive engine components.
- They will be introduced to the promising role of manganese to the mechanical behavior of aluminum alloys.
- The conclusions out of the paper may open the door for a great set of research ideas.