Aging Behaviors of Al 6061 and Al 6061/SiCp Composite

Abstract

In the present research the aging behavior of Al6061 alloy and Al6061/SiCp composite fabricated by powder metallurgy method was investigated. The solution treatment of the samples were carried out at 527°C for 2, 3and 4 h followed by aging at 180°C for different aging times between 1 and 10 h. The existence of SiC particles led to increasing the peak hardness of the composite. The peak hardness of the composite took place at shorter times than that of the 6061 alloy for the samples solution treated for 3and 4 h, but took place at longer times for the samples solution treated for 2 h. The optimum solution treating time was about 3 h for both the composite and the 6061 alloy that led to the fastest aging kinetics and the maximum hardness. At the solution treating time shorter than 3h due to incomplete dissolution of precipitates, the aging kinetics decelerated and the hardness values decreased. For the composites solution treated more than 3 h, hardness values decreased due to the grain growth of matrix while changing in the aging kinetics was not significant. EDS and SEM studies indicated the presence of bight enrichment zones including Mg and Si elements in the composite in solution treatment conditions.

Effects of TiB2 particles on aging behavior of in-situ TiB2/Al–Cu–Mg composites

“…It has been widely reported that after suitable solution treatment, it takes shorter time for the composites to reach the peak hardness compared with the alloys since the precipitation is accelerated, such as AA2024 alloy/SiC p [6], SiC w /AZ91 [7], in-situ TiB 2 /A356 [8], AA6061/ SiC w [9], and AA6061/SiC p [10] composites. However, other researchers [11] take issue with this experimental result and claim that after solution treatment, the precipitation is inhibited in the composites.…”

Silicon Nitride Whisker-Reinforced Aluminum Matrix Composites: Twinning and Precipitation Behavior

“…However, significant retardation in the aging kinetics of the composites has also been reported due to a reduction in the retained vacancies and the formation of interfacial phases [13,[27][28][29][30]. The interfaces and dislocations could act as sinks for the vacancies, leading to a delayed formation of Guinier-Preston (GP) zones [31,32].…”