Development in mechanical and fatigue properties of AA6061/AL2O3 nanocomposites under stirring temperature (ST)

Abstract

Aluminum is expected to remain the core material for many critical applications such as aircraft and automobiles. This is due to the high resistance to different environmental conditions, desired and manageable mechanical properties, as well as high fatigue resistance. Aluminum nanocomposites such as AA6061/Al2O3 can be made in many ways using a liquid metallurgy method. The main challenges for this method in the production of nanocomposites are the difficulties of achieving a uniform distribution of reinforcing materials and possible chemical reactions between the reinforcing material and the matrix. For structural applications exclusive to aerospace sectors. The growing cost-effective nanocomposites mass production technology with essential operational and geometric flexibility is a big challenge all the time. Each method of preparing AA6061/Al2O3 nanocomposites can provide different mechanical properties. In the present study, nine nanocomposites were prepared at three stirring temperatures (800, 850, and 900 °C) with the level of Al2O3 addition of 0, 5, 7, and 9 wt %. The results of tensile, hardness and fatigue tests revealed that the composite including 9 wt % Al2O3 with 850 °C stirring temperatures has the best properties. It was also revealed that the 850 °C stirring temperature (ST) with 9 wt % Al2O3 composite provide an increase in tensile strength, VHN and reduction in ductility by 20 %, 16 % and 36.8 % respectively, compared to zero-nano. Also, the fatigue life at the 90 MPa stress level increased by 17.4 % in comparison with 9 wt % nanocomposite at 800 °C (ST). Uniform distributions were observed for all nine microstructure compositions.

Identifying regularities of high temperature on constant and variable fatigue life of AA7075-Al2O3 nanocomposite fabricated by stir casting method

“…The effect of stirring temperature (ST) on the mechanical and fatigue properties of AA6061/AL 2 O 3 nanocomposites was investigated by the paper [4]. They fabricated the composites using stir casting and conducted mechanical tests.…”

“…Comparison between 17 lowered by 43.963 % at stress level of 540 MPa [11]. Fatigue life experimental results showed that an increase of 17.4 % when addition 9 wt % of Al 2 O 3 to AA6061 compared to matrix fatigue results [4]. The following factors may contribute to improve the fatigue life and strength [10,12]:…”