Accession Number:

ADA474421

Title:

Development of Advanced Oxide Dispersion Strengthened Tungsten Heavy Alloy for Penetrator Application

Descriptive Note:

Final rept.

Corporate Author:

KOREA ADVANCED INST OF SCIENCE AND TECHNOLOGY DAEJEON (KOREA)

Report Date:

2005-09-30

Pagination or Media Count:

47.0

Abstract:

The effects of fabrication process parameters, including conditions for powder preparation, sintering, cyclic heat-treatment, swaging, and annealing processes, on microstructures and staticdynamic mechanical properties of ODS tungsten heavy alloys were investigated. The composition of ODS tungsten heavy alloys was designed as 94W-4.56Ni-1.14Co-0.3Y2O3 which show the highest strength at similar microstructural parameters based on the analysis of microstructures and mechanical properties. The two-stage sintered ODS tungsten heavy alloy showed finer tungsten grain size than those prepared by conventional liquid phase sintering with similar matrix volume fraction and tungstentungsten contiguity. Cyclic heat-treatment process was introduced after sintering process to increase the tensile strength and elongation by decreasing the tungstentungsten contiguity. The swaging and annealing processes of ODS tungsten heavy alloy increase the tensile strength with decreasing the elongation. High strain rate dynamic compressive tests were performed by Hopkinson pressure bar test equipment. The dynamic compressive strength of ODS tungsten heavy alloys was improved by addition of oxide dispersoids and by modification of composition from W-Ni-Fe to W-Ni-Co. At the same time, the adiabatic shear bands induced by high strain rate dynamic shear tests became narrower by the dispersion of Y2O3 and by the composition modification. The 94W-4.56Ni-1.14Co-0.3Y2O3 alloy, which was two-stage sintered, cyclic heat-treated, swaged, and annealed, shows high ultimate tensile strength of 1350MPa, moderate elongation of 5 and high compressive yield strength of 1800MPa under a high strain rate deformation of 3000s. The 94W-4.56Ni-1.14Co-0.3Y2O3 ODS tungsten heavy alloy has been suggested as an advanced core material for kinetic energy penetrators and hard target penetrators.

Subject Categories:

  • Inorganic Chemistry
  • Metallurgy and Metallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE