Accession Number:

AD0603301

Title:

TUNGSTEN BASE ALLOYS HOT PRESSED FROM ELEMENTAL POWDERS,

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF

Personal Author(s):

Report Date:

1964-06-18

Pagination or Media Count:

21.0

Abstract:

The consolidation of refractory metal alloys 80W-10Mo 10Cb and 68W-20Ta-12Mo from elemental powders of W, Ta, Mo and Cb by mechanical mixing and hot pressing above 2100C was encouraging. A study of compositional uniformity by electron microprobe analysis revealed that the most critical factor in promoting a homogeneous alloy is the starting particle size. Rather uniform composition can be obtained in the hot-pressed condition when all constituent powders are finer than 5 microns. Electron beam melting of these alloys resulted in larger concentration gradients than those obtained by solid state consolidation due to solidification segregation. Cold pressing and sintering resulted in homogeneity equal to the hot pressed material however, relative density was less than 85 percent after vacuum sintering up to 2800C compared to better than 97 percent in the hot-pressed condition. The high temperature stabilities as indicated by grain growth and hardness measurements are treated. Relative diffusion rates of the alloying elements which control ultimate uniformity are also revealed from the experimental data. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE