Microdomain structure and some related properties of block copolymers. II. Plastic deformation mechanisms of the glassy component in rubber-toughened plastics

1980 ◽  
Vol 17 (3) ◽  
pp. 427-472 ◽  
Author(s):  
Hiromichi Kawai ◽  
Takeji Hashimoto ◽  
Katsunori Miyoshi ◽  
Hiroyuki Uno ◽  
Mineo Fujimura
1981 ◽  
Vol 54 (5) ◽  
pp. 1011-1041 ◽  
Author(s):  
Hiromichi Kawai ◽  
Takeji Hashimoto ◽  
Katsunori Miyoshi ◽  
Hiroyuki Uno ◽  
Mineo Fujimura

Abstract The toughening mechanism was investigated by means of mechanical and optical techniques including electron microscopy and polarized light scattering for wide variety of domain morphologies of di- and triblock copolymers and their blends with corresponding homopolymers. Two types of plastic deformation mechanisms of the glassy component are emphasized as the toughening mechanism. One is large plastic deformation of the glassy component, as bulk, followed by its plastic flow or fragmentation, depending on the di- or triblock sequence arrangement. The other is the development of a microcraze at the boundary of the rubber particle, and its propagation through the glassy matrix. The origins of the two types of plastic deformation mechanisms are postulated as hydrostatic pressure effects upon the high plasticity of the glassy component due to differences of Poisson's ratios between the glassy and rubbery components and also as stress concentration effects of the rubber particle at the glassy phase opposite to the equatorial zone of the rubber particle with respect to the principal stress direction. The nearer the volume fraction of the two components to 50/50, the more efficient are the hydrostatic pressure effects upon inducing high plasticity in the glassy component. On the other hand, the smaller the radius of curvature at the equatorial zone of the rubber particle, the more concentrated the stress level becomes to generate the microcraze and further microcracks. Thus, there must be an optimum size of the rubber particle to generate the microcrazes in the most efficient rate. The system of alternating lamellar microdomains is sufficient for the generation of high plasticity, but insufficient for the craze development due to a too large radius of curvature to elevate the concentrated stress, if any. The toughening mechanism in rubber-toughened plastics can be explained generally in terms of these counter-balanced factors for the two types of plastic deformation mechanisms of the glassy component.


2021 ◽  
Vol 807 ◽  
pp. 140821
Author(s):  
Kai Zhang ◽  
Zhutao Shao ◽  
Christopher S. Daniel ◽  
Mark Turski ◽  
Catalin Pruncu ◽  
...  

2010 ◽  
Vol 667-669 ◽  
pp. 253-258
Author(s):  
Wei Ping Hu ◽  
Si Yuan Zhang ◽  
Xiao Yu He ◽  
Zhen Yang Liu ◽  
Rolf Berghammer ◽  
...  

An aged Al-5Zn-1.6Mg alloy with fine η' precipitates was grain refined to ~100 nm grain size by severe plastic deformation (SPD). Microstructure evolution during SPD and mechanical behaviour after SPD of the alloy were characterized by electron microscopy and tensile, compression as well as nanoindentation tests. The influence of η' precipitates on microstructure and mechanical properties of ultrafine grained Al-Zn-Mg alloy is discussed with respect to their effect on dislocation configurations and deformation mechanisms during processing of the alloy.


2007 ◽  
Vol 1049 ◽  
Author(s):  
Yongjiang Huang ◽  
Nursiani Indah Tjahyono ◽  
Jun Shen ◽  
Yu Lung Chiu

AbstractThis paper summarises our recent cyclic nanoindentation experiment studies on a range of materials including single crystal and nanocrystalline copper, single crystal aluminium and bulk metallic glasses with different glass transition temperatures. The unloading and reloading processes of the nanoindentation curves have been analysed. The reverse plasticity will be discussed in the context of plastic deformation mechanisms involved. The effect of loading rates on the mechanical properties of materials upon cyclic loading will also be discussed.


Nanomaterials ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 3014
Author(s):  
Chao Xu ◽  
Futi Liu ◽  
Chunmei Liu ◽  
Pei Wang ◽  
Huaping Liu

Although ZnSe has been widely studied due to its attractive electronic and optoelectronic properties, limited data on its plastic deformations are available. Through molecular dynamics simulations, we have investigated the indentations on the (001), (110), and (111) planes of ZnSe nano films. Our results indicate that the elastic modulus, incipient plasticity, elastic recovery ratio, and the structural evolutions during the indenting process of ZnSe nano films show obvious anisotropy. To analyze the correlation of structural evolution and mechanical responses, the atomic displacement vectors, atomic arrangements, and the dislocations of the indented samples are analyzed. Our simulations revealed that the plastic deformations of the indented ZnSe nano films are dominated by the nucleation and propagation of 1/2<110> type dislocations, and the symmetrically distributed prismatic loops emitted during the indenting process are closely related with the mechanical properties. By studying the evolutions of microstructures, the formation process of the dislocations, as well as the formation mechanisms of the emitted prismatic loops under the indented crystalline planes are discussed. The results presented in this work not only provide an answer for the questions about indentation responses of ZnSe nano films, but also offer insight into its plastic deformation mechanisms.


2021 ◽  
Vol 2144 (1) ◽  
pp. 012022
Author(s):  
N N Andrianova ◽  
A M Borisov ◽  
E S Mashkova ◽  
M A Ovchinnikov ◽  
V S Sevostyanova

Abstract The modification of the surface of highly oriented pyrolytic graphite (HOPG) under 10, 20 and 30 keV Ar+ ions irradiation with fluence 1018 cm−2 at the irradiation temperature of 250°C has been studied experimentally. An anomalous growth of the ion-induced surface relief of HOPG have been found. This effect, like the well-known effect of anomalous deep embedded argon ions in HOPG, is analyzed within the framework of plastic deformation mechanisms in graphite.


JOM ◽  
2010 ◽  
Vol 62 (12) ◽  
pp. 44-51 ◽  
Author(s):  
Ralph D. Nyilas ◽  
Stephan Frank ◽  
Ralph Spolenak

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