scholarly journals Critical Strains Determine the Tensile Deformation Mechanism in Semicrystalline Polymers

2020 ◽  
Vol 53 (21) ◽  
pp. 9155-9157
Author(s):  
Yongfeng Men
Keyword(s):  
Deformation Mechanism ◽  
Tensile Deformation ◽  
Semicrystalline Polymers ◽  
Critical Strains

Quantification of Cavitation in Neat and Calcium Carbonate-Filled High-Density Polyethylene Subjected to Tension

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
F. Addiego ◽  
J. Di Martino ◽  
D. Ruch ◽  
A. Dahoun ◽  
O. Godard ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
High Density Polyethylene ◽  
Shape Factor ◽  
Tensile Deformation ◽  
Quantitative Information ◽  
Semicrystalline Polymers ◽  
High Density ◽  
Deformation State ◽  
Microscopic Features ◽  
Void Shape

Cavitation-induced deformation mechanisms in neat semicrystalline polymers, i.e., crazing, and in the derived composites, i.e., particle-matrix debonding, are generally activated during the transition between viscoelastic and viscoplastic deformation stages. However, little quantitative information about the void evolution with the drawing level is to date available in the literature. The objective of this work is to quantify cavitation mechanisms in neat and calcium carbonate-filled high-density polyethylene (HDPE) subjected to tensile deformation. Attention was first focused on the properties of the materials that were assessed by means of a thermogravimetric analyzer, a differential scanning calorimeter, a scanning electron microscope (SEM), and a dynamic mechanical analyzer. In a second step, macroscopic aspects of cavitation were studied by quantifying volume variation of the materials subjected to tension using an accurate optical extensometer (VidéoTraction). Attention was then turned to microscopic features of cavitation through a careful quantification of void density and shape factor by means of a method coupling a SEM with an image analysis procedure. At the two scales of interest, the results demonstrate that (i) the void density generated by crazing in neat HDPE or particle-matrix debonding in the composites gradually increases with the deformation state, (ii) void density induced by debonding is higher than that generated by crazing, and (iii) decreasing particles size causes an increase of void density. We also estimated the void shape factor, that is, ratio between the height and the width of the cavities. In all the studied materials, this parameter starts from a value that is below 1 and increases by a factor of 2 with increasing deformation. Moreover, in the case of the composites, one notes a higher void shape factor compared with the neat material, and particle size does not influence this parameter. The results provided by this paper can be the basis of a physically based model predicting cavitation mechanisms in semicrystalline polymers.

Tensile deformation mechanism of Sn-37Pb solder alloy at cryogenic temperatures

2021 ◽  
Author(s):  
Xiaotong Guo ◽  
Kun Zhang ◽  
Jiahao Liu ◽  
Yong Li ◽  
Xinlang Zuo ◽  
...  
Keyword(s):  
Solder Alloy ◽  
Deformation Mechanism ◽  
Tensile Deformation ◽  
Cryogenic Temperatures

scholarly journals The Influence of Warm Rolling Reduction on Microstructure Evolution, Tensile Deformation Mechanism and Mechanical Properties of an Fe-30Mn-4Si-2Al TRIP/TWIP Steel

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 742 ◽  
Author(s):  
Yanchun Dong ◽  
Zhilin Sun ◽  
Hao Xia ◽  
Jianhang Feng ◽  
Jiejie Du ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Microstructure Evolution ◽  
Deformation Mechanism ◽  
Twip Steel ◽  
Tensile Deformation ◽  
Warm Rolling ◽  
Rolling Reduction ◽  
Dislocation Glide ◽  
Work Hardening Rate

The effects of warm rolling reduction ratio ranging from 20% to 55% on microstructure evolution, the tensile deformation mechanism, and the associated mechanical properties of an Fe-30Mn-4Si-2Al TRIP/TWIP steel were studied. The warm rolling process resulted in the formation and proliferation of sub-structure, comprising dislocations, deformation twins as well as shear bands, and the densities of dislocation and twins were raised along with the increase in rolling reduction. The investigated steel, with a fully recrystallized state, exhibited a single ε-TRIP effect during the room temperature tensile deformation, on top of dislocation glide. However, the formation and growth of twin lamellae and ε-martensite were detected simultaneously during tensile deformation of the warm rolled specimen with rolling reduction of 35%, leading to a good balance between high yield strength of 785 MPa, good total ductility of 44%, and high work hardening rate. As the rolling reduction increased to 55%, the specimen revealed a relatively low work hardening rate, due to the high dislocation density, and dislocation glide was the main deformation mechanism. As a result, a tensile deformation mechanism that started from a single ε-martensitic transformation moved to a bi-mode of ε-martensitic transformation accompanied with deformation twinning, and finally to dislocation glide with the increasing warm rolling reduction was proposed.

Anomalous Twinning as the Macroscopic Deformation Mechanism for AZ31 Magnesium Alloy

2019 ◽  
Vol 810 ◽  
pp. 95-100
Author(s):  
Yusuke Onuki ◽  
Shigeo Sato
Keyword(s):  
Magnesium Alloy ◽  
Deformation Mechanism ◽  
Tensile Deformation ◽  
Tensile Axis ◽  
Rolling Direction ◽  
Az31 Magnesium Alloy ◽  
Uniaxial Tensile ◽  
Rolled Sheet ◽  
Prism Slip ◽  
Texture Measurement

In order to study the plastic deformation mechanism of AZ31 magnesium alloy, in situ texture measurement during uniaxial tensile deformation is conducted by using neutron diffraction. The specimen is prepared from a rolled sheet so that the deformation axis is parallel to the rolling direction. By increasing strain, the alignment of <10-10> along the tensile axis is strengthened, which is due to the activation of the prism slip system. The basal pole concentration at the prior sheet normal direction is slightly decreased by the deformation and the new texture component is formed at the transvers direction. This can be understood by activation of the {10-12} tension twinning. These results indicate that the tension twinning plays an important role even when the tensile deformation is applied parallel to the basal plane.

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