HIGH-PRESSURE PHASE TRANSFORMATIONS IN LABORATORY MECHANICAL MIXERS AND MORTARS

Abstract

Pressure effects produced by mixing and grinding devices were studied for PbO2, CaCO3, MnF2, BeF2, SiO2, PbO, Sb2O3, B2O3, and BAsO4; transition pressures at room temperature were 10,000, 3,000, 9,500, 15,500, 13,500, 5,500, 10,000, 18,500, and 30,000 bars, respectively. Results showed that (1) grinding or mixing in both automatic mortars and Wig-L-Bug-type shakers not only can introduce appreciable amounts of surface and strain energy, but also can generally cause the formation of high-pressure phases; (2) the effective maximum pressures obtainable in such instruments is not less than 15,000 bars; and (3) in addition to the quasi-hydrostatic pressures, shearing stresses effect marked acceleration of the transformations.

Document Details

Document Type
Technical Report
Publication Date
Jun 28, 1961
Accession Number
AD0260915

Entities

People

  • Frank Dachille
  • Rustum Roy

Organizations

  • Pennsylvania State University

Tags

Communities of Interest

  • Weapons Technologies

DTIC Thesaurus Topics

  • Automatic
  • Buildings And Structures
  • Critical Temperature
  • Dynamic Pressure
  • Glass Transition Temperature
  • High Pressure
  • Hydrostatic Pressure
  • Phase Transformations
  • Physics Laboratories
  • Research Facilities
  • Static Pressure
  • Transition Temperature
  • Transitions

Readers

  • Combustion science or combustion engineering.
  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.