Development of a Precipitation-Strengthened Matrix for Non-quenchable Aluminum Metal Matrix Composites

Abstract

Recent developments in metal matrix composite-encapsulated ceramic armor show promise in lightweight armor technology. The system contains ceramic tiles, such as alumina, sandwiched between unreinforced aluminum or aluminum metal matrix composite (Al-MMC), which has a better toughness compared to the ceramic tiles. The sandwich structures should not be quenched during the fabrication, as the large mismatch in the coefficients of thermal expansion between the ceramic tiles and the unreinforced aluminum or Al-MMC creates internal stresses high enough to fracture the ceramic tiles. However, slow cooling of most commercial alloys creates large precipitates making solute unavailable for the formation of fine precipitates during aging. Here, we develop a non-quenched, high-strength metal matrix utilizing dilute Al-Sc-Zr alloys. We demonstrate that the dilute Al-0.09 Sc-0.045 Zr at.% alloy and the same alloy containing 0-4 vol.% alumina short fibers do not result in precipitation upon slow cooling from a high temperature, and can thereafter be aged to increase their strength. They exhibit a moderate strength, but improved ductility and toughness as compared to common armor aluminum alloys, such as AA5083-H131, making them attractive as armor materials and hybrid armor systems.

Assessment of the Impact Resistance of a Composite Material with EN AW-7075 Matrix Reinforced with α-Al2O3 Particles Using a 7.62 × 39 mm Projectile

“…Cermets can largely replace the standard material in the form of classical ballistic ceramics and the works conducted [24][25][26][27] are aimed at searching for proper structures which absorb the energy of the ballistic impact. The metal matrix composite is mainly used in armouring applications to prevent perforation.…”

Effect of laser rescanning on the grain microstructure of a selective laser melted Al-Mg-Zr alloy

“…This alloy was specifically developed to provide, after additive manufacturing, high strength and ductility at ambient temperature as well as high creep-and coarsening resistance at elevated temperatures [17]. Aluminum alloys with less than ~0.7 wt.% Zrprocessed via conventional casting have been studied extensively [18][19][20][21][22], but little research has been conducted on Zr-richer alloys, with much higher liquidus temperatures and very broad liquidus-solidus ranges In this paper we show that Addalloy™ can tolerate higher Zr content due to the very rapid solidification achieved via SLM, thus providing higher Zr content for meta-stable L1 2 -Al 3 Zr. We study here the potential for grain microstructure modification via single and multiple laser scanning on Addalloy™ which displays a duplex grain structure and L1 2 -structured Al 3 Zr nano-precipitates.…”

Mechanical Properties as a Function of Casting Process of Aluminum–Silicon Alloy Matrix Composites

“…There are several reasons for this, including the following: The density of dislocations in the field increases due to the thermal incompatibility stress, which increases the strength of the field, and, as a result, composites. But many of the factors reduce the stress on composite materials (compared to the mixing rule) [10][11][12][13][14]. Therefore, depending on the overall effect of all the factors involved, the behavior of the composite form change will be different.…”