Properties and Protection of Wrought ZW3 and ZK60A Mg-Zn-Zr Magnesium Alloys
Technical Report,15 Nov 2003,20 Oct 2016
CCDC Army Research Laboratory Aberdeen Proving Ground United States
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This report characterizes microstructure, Charpy impact toughness, tensile properties, ballistic V50 protection, and failure fracture modes of magnesium-zinc-zirconium Mg-Zn-Zr alloys ZK60A-T5 Mg-6.0Zn-0.45Zr and ZW3 Mg-3.0Zn-0.6Zr ZK30. ZK60A-T5 and ZW3 flat profiles were extruded to thicknesses 25.4 mm, 38.1 mm, and 50.8 mm, 254 mm width, under respective specifications ASTM B 107B-13 and BS 2L 505. The ZW3 and ZK60A-T5 failure modes and material properties are characterized with microstructure, fracture features, and Charpy instrumented test IT measurements of force, energy, displacement, and time. Mechanical tests in tension demonstrate properties of strength and ductility and flow curves. True stress versus true strain properties and flow curves reveal strength, ductility, and power-law hardening. The Charpy IT shows the ductile displacement and fracture, the unstable crack fracture modes, and duration time period for non-catastrophic fracture by plastic displacement. V50 tests reveal protection levels and failure modes versus the 0.30-cal. APM2 projectile and 0.50-cal. fragment-simulating projectile FSP. Areal density AD V50 plots compare the ballistic protection performances to Mg AZ31-H24, WE43-T5, Mg-13Li-6Al, and aluminum Al 5083, 7039, 7020-T651, and 7017 protection materials. Charpy IT results of un-notched ZW3 specimens demonstrate excellent Mg toughness in force-displacement and duration of force-time, better than AM50 Mg-Al-Mn crash protection alloy. The 0.30-cal. APM2 V50 protection meets or exceeds 5083 Al and AZ31 Mg levels 0.50-cal. FSP protection exceeds the AZ31B Mg, and 5083 Al levels up to 64 kgm2 AD. High tensile-ductility properties of ZW3 suggest capability to roll plate and to mitigate anisotropy effects in plate shapes.
- Metallurgy and Metallography