Accession Number : AD0269237

Title :   STRAIN AGING IN MOLYBDENUM

Corporate Author : AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : WILSON,ROBERT J.

Report Date : AUG 1961

Pagination or Media Count : 1

Abstract : A study of the characteristics of strain aging in commercial-purity Mo by the methods of dynamic modulus recovery and yield point return, and a determination of the activation energy of strain aging was made. Modulus specimens, from arc-cast, recrystallized Mo, in the shape of rectangular bars were deformed 3% in compression. The return of Young's modulus was investigated as a function of aging time and temperature. Measurements of resonant frequency were made at room temperature. The rate of increase of the square of resonant frequency, rather than modulus recovery was used to plot the data for determining an activation energy. Tensile specimens from powder-metallurgy Mo sheet were given 2% plastic deformation by straining to the end of the lower yield stress. The rate of return of yield point with aging time and temperature was plotted. The rate of Young's modulus recovery gave values of activation energy from 24,000 to 28,000 cal/mol. The rate of yield point return gave a single value of 24,000 cal/mol. (Author)

Descriptors :   *MOLYBDENUM, AGING (PHYSIOLOGY), CRYSTAL STRUCTURE, CRYSTALS, DEFORMATION, ELASTIC PROPERTIES, LIQUID METALS, MEASUREMENT, TENSILE PROPERTIES, TEST METHODS

Distribution Statement : APPROVED FOR PUBLIC RELEASE