The effect of the precipitate size distribution on the aging curve of order hardening alloys

Journal Article · Fri Apr 01 04:00:00 EST 1988 · Acta Metall.; (United States)

DOI:https://doi.org/10.1016/0001-6160(88)90145-9· OSTI ID:6896374

Glazer, J; Morris, Jr, J W

The effect of the shape of the precipitate size distribution on the age-hardening behavior of alloys strengthened by ordered precipitates is investigated using a modified version of the Hanson and Morris strong line model for the critical resolved shear stress. This model accounts for the influence of dislocations self-interactions on the effective strength of obstacles to dislocation glide. The model predicts that the largest precipitates are responsible for the peak in strength, but that the value of the peak strength is determined principally by the average precipitate radius at peak strength. The peak strength for a given volume fraction is maximized if all of the precipitates are the same size. These qualitative results are used to interpret existing data on the effect of the precipitate size distribution. The contributions of obstacles of differing strengths are included through a quadratic sum rule. Binary aluminum-lithium alloys are used as a model system with which to examine the quantitative accuracy of the model.

• Research Organization: Dept. of Materials Science and Mineral Engineering, Univ. of California, Berkeley and Center for Advanced Materials, Lawrence Berkeley Lab., Berkeley, CA (US)
• OSTI ID: 6896374
• Journal Information: Acta Metall.; (United States), Journal Name: Acta Metall.; (United States) Vol. 36:4; ISSN AMETA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102 -- Metals & Alloys-- Structure & Phase Studies
360103* -- Metals & Alloys-- Mechanical Properties
ACCURACY
AGE HARDENING
AGING
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
BINARY ALLOY SYSTEMS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DISLOCATIONS
HARDENING
LINE DEFECTS
LITHIUM ALLOYS
MATHEMATICAL MODELS
PARTICLE MODELS
PRECIPITATION HARDENING
SHAPE
SHEAR
SIZE
STRAIN HARDENING
STRONG-COUPLING MODEL