An analysis based on plastic strain energy for bilinearity in Coffin-Manson plots in an Al-Li alloy

Journal Article · Wed Jun 15 04:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90297-6· OSTI ID:7303334

Prasad, N E; Paradkar, A G; Malakondaiah, G ^[1]; Kutumbarao, V V ^[2]

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1. Defence Metallurgical Research Lab., Hyderabad (India)
2. Banaras Hindu Univ., Varanasi (India). Dept. of Metallurgical Engineering

Fatigue failure of a component occurs through an irrecoverable energy dissipating process. The alloy dissipates most of the plastic strain energy as heat, the other forms being vibration and acoustic emission. Some energy will be absorbed by immobile life defects and by surface damage processes. In order to gain greater understanding of the material response to fatigue damage, it is necessary to propose a physical quantity with energy dissipation as a fatigue damage parameter. Two such widely used fatigue damage parameters are the average plastic strain energy per cycle ([Delta]W[sub p]), the area under the hysteresis loop during low cycle fatigue and the total dissipated energy (W[sub f]), the sum of the areas of all the loops before failure. Each alloy has a certain capacity to dissipate the plastic strain energy. When this limit is attained, the cracks which originated during the earlier cycling will propagate and failure occurs. This paper presents the results of the analysis of the low cycle fatigue data obtained in the case of a quaternary Al-Li-Cu-Mg alloy. The aim of this analysis is to provide further understanding on the bilinear nature of the Coffin-Manson power law relationship, which has already been reported by several researchers.

• OSTI ID: 7303334
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 30:12; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ALLOY SYSTEMS
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
COPPER ALLOYS
CRACK PROPAGATION
DATA
ENERGY LOSSES
EXPERIMENTAL DATA
FATIGUE
INFORMATION
LITHIUM ALLOYS
LOSSES
MAGNESIUM ALLOYS
MECHANICAL PROPERTIES
NUMERICAL DATA
QUATERNARY ALLOY SYSTEMS