Accession Number : AD0867106

Title :   Feasibility Study for Development of an Aluminum Alloy for Fabrication of Small Arms Cartridge Cases.

Descriptive Note : Final rept. 28 Jun 68-28 Oct 69,

Corporate Author : ALUMINUM CO OF AMERICA ALCOA CENTER PA ALCOA LABS

Personal Author(s) : Rogers, Ralph W., Jr

Report Date : 24 NOV 1969

Pagination or Media Count : 70

Abstract : Five experimental, low impurity content aluminum alloys were evaluated for characteristics such as tensile properties, fracture toughness, resistance to corrosion and stress corrosion, temperature stability and quench sensitivity. Although none of the alloys achieved the target strength-toughness criteria, two compositions were superior to conventional alloys in this respect. These were nominally Al-5 Zn-2.4 Mg-1.2 Cu-.15 Cr (MA07) and Al-5.9 Zn-2.4 Cu-2.2 Mg-.3 Mn (MA08). One strain-hardenable alloy, Al-7.5 Mg-.1 Mn-.1 Cr (MA09) was included in the evaluation and displayed good notch toughness and moderate resistance to crack growth but at a relatively low strength level compared to the heat-treatable alloys. Electron metallography and fractography showed fracture toughness to depend upon the relative proportions of fracture path that were intergranular or transgranular and, hence, upon relative strengths of grain interiors and boundaries. The effect of second-phase constituent particles upon fracture toughness was not discernible at the low insoluble element level of these alloys. (Author)

Descriptors :   (*CARTRIDGE CASES, SMALL ARMS AMMUNITION), (*ALUMINUM ALLOYS, METALLOGRAPHY), HEAT TREATMENT, AGING(MATERIALS), DISPERSION HARDENING, GRAIN STRUCTURES(METALLURGY), STRESS RELIEVING, CORROSION RESISTANCE, STRESS CORROSION, CRACKS, HARDNESS, THERMAL STABILITY, QUENCHING, MAGNESIUM ALLOYS, MATERIAL FORMING, FRACTOGRAPHY, ZINC ALLOYS, AGE HARDENING, COPPER ALLOYS, STRAIN HARDENING, TENSILE PROPERTIES, TEMPERATURE, ROLLING(METALLURGY), FRACTURE(MECHANICS), YIELD POINT, TOUGHNESS, NOTCH TOUGHNESS.

Subject Categories : Properties of Metals and Alloys
      Fabrication Metallurgy
      Ammunition and Explosives

Distribution Statement : APPROVED FOR PUBLIC RELEASE