Accession Number : AD0824168

Title :   DEFORMATION AND FRACTURE AS A FUNCTION OF STRAIN RATE AT HOT WORKING TEMPERATURES.

Descriptive Note : Final rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE

Personal Author(s) : Grant, Nicholas J. ; Bridenbaugh, Peter ; Kane, Robert

Report Date : SEP 1967

Pagination or Media Count : 33

Abstract : The intent of this program, originally, was to determine the role of strain rate and temperature on the hot plasticity of several classes of metals and alloys. The strain rates were comparable to those encountered in usual hot working operations, including extrusion; they varied from about 0.001 to 100 per second. It was also an intent of this program to study the deformation and fracture mechanisms which prevailed in such high strain rate tests. Both cast and wrought structures were of interest to our studies since the great bulk of all metals and alloys utilized in this world usually start as cast ingot structures. Further, the selection of materials for test was such that both single-phase and multi-phase alloys would be included, the multi-phase alloys involving both soft and hard second phases. In the course of these studies, when it became obvious that relatively low values of ductility were being obtained under the optimum conditions of strain rate and temperature, even for pure metals, means were sought to enhance the hot plasticity. One of the evident limitations of cast structures was the very coarse grain size, from 2 to 20 mm diameter; a second shortcoming was the rapid increase in grain size of the more ductile wrought materials when heating to the high test temperatures.

Descriptors :   (*DEFORMATION, METALS), (*FRACTURE(MECHANICS), METALS), (*PLASTIC PROPERTIES, THERMAL PROPERTIES), RUPTURE, IRON, MOLYBDENUM, MOLYBDENUM ALLOYS, NICKEL ALLOYS, CREEP, STRESSES, TEMPERATURE, TABLES(DATA), ELONGATION, STRAIN(MECHANICS).

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE