Mechanisms of plastic instability and fracture of compressed and tensile tested Mg-Li alloys investigated using the acoustic emission method
Journal Title: Frattura ed Integrità Strutturale - Year 2016, Vol 10, Issue 35
Abstract
The results of the investigation of both mechanical and acoustic emission (AE) behaviors of Mg4Li5Al alloy subjected to compression and tensile tests at room temperature are compared with the test results obtained using the same alloy and loading scheme but at elevated temperatures. The main aim of the paper is to investigate, to determine and to explain the possible influence of factors related with enhanced internal stresses such as: segregation of precipitates along grain boundaries or solute atoms along dislocations (Cottrell atmospheres) or dislocation pile-ups at grain boundaries which create very high stress concentration leading to fracture. The results show that the plastic instabilities are related to the Portevin–Le Châtelier phenomenon (PL effect) and they are correlated with the generation of AE peaks. The fractography of breaking samples was analyzed on the basis of light (optical), TEM and SEM images.
Authors and Affiliations
A. Pawelek, W. Wajda, B. Grzegorczyk, Z. Ranachowski, S. Kúdela, Jr.
Biaxial fatigue behavior of a powder metallurgical TRIP steel
Multiaxial fatigue behavior is an important topic in critical structural components. In the present study the biaxial-planar fatigue behavior of a powder metallurgical TRIP steel (Transformation Induced Plasticity...
Computed Tomography analysis of damage in composites subjected to impact loading
The composites, used in the transportation engineering, include different classes with a wide range of materials and properties within each type. The following different typologies of composites have been investigated:...
Evaluation of seismic mitigation of embankment model
Conducting experiment on embankment model by shaking table could be an accurate method to evaluate the behavior of embankment or any structures under seismic loading. In this research work, in order to assess the functi...
Crack path predictions and experiments in plane structures considering anisotropic properties and material interfaces
In many engineering applications special requirements are directed to a material's fracture behavior and the prediction of crack paths. Especially if the material exhibits anisotropic elastic properties or fractur...
A micromechanical four-phase model to predictthe compressive failure surface of cement concrete
In this work, a micromechanical model is used in order to predict the failure surface of cementconcrete subject to multi-axial compression. In the adopted model, the concrete material is schematised as acomposite w...