No abstract available

[en] Graphene is intrinsically ultra-stiff in its plane. Its huge mechanical mismatch when interfacing with ultra-compliant biological tissues and elastomers (7–9 orders of magnitude difference in stiffness) poses significant challenge in its application to functional devices such as epidermal electronics and sensing prosthesis. We offer a feasible and promising solution to this significant challenge by suitably patterning graphene into a nanomesh. Through systematic coarse-grained simulations, we show that graphene nanomesh can be made extremely compliant with nearly zero stiffness up to about 20% elongation and then remain highly compliant up to about 50% elongation

[en] The article A microstructural insight into the hygro-mechanical behaviour of a stabilised hypercompacted earth, written by Agostino Walter Bruno, Céline Perlot, Joao Mendes, Domenico Gallipoli, was originally published online without Open Access.

[en] Mg alloys are receiving extensive attention as bone implants owing to their biodegradability, biocompatibility and mechanical property. However, their too rapid degradation rate and non-uniform degradation mode result in mechanical integrity losing prematurely. In order to enhance degradation resistance and form uniform degradation mode of Mg alloys, rare earth element gadolinium (Gd) was introduced to Mg-3Zn-0.5Zr (wt%) (ZK30) alloy to form a long period stacking ordered (LPSO) phase (Mg₁₂ZnGd) distributed in grain interior. The results showed that ZK30-Gd alloy with LPSO phase distributed in grain interior possessed uniform degradation mode and improved degradation resistance. It was explained that the LPSO phase was an unstable fault phase and preferentially degraded which subsequently formed compact degradation product films along with the degradation of the LPSO phase, which displayed a protection effect to the Mg matrix. Moreover, the LPSO phase had a parallel lamellar structure in the grain interior, which inhibited the degradation extending to the neighboring grains. Furthermore, the ZK30-Gd alloy also exhibited good cytocompatibility. These results showed that the ZK30-Gd alloy might be a potential bone implants. (paper)

[en] Short communication

[en] This research explored the metallurgical and mechanical properties of arc welding of copper related with influence of Argon, Helium and mixtures of them. Copper plates of 6 mm thickness were welded with different mixtures of the mentioned gases. The radiography of welded specimens with 100% He and 100% Ar does not show show any porosity. On the other hand, the copper plates welded different gas mixtures presented uniform porosity in the welded zone. The metallographies show recrystallized grain in the heat affected zone, while the welding zone showed a dendritic structure. The results of the tensile strength vary between a maximum of 227 MPa for 100% He and a minimum of 174 MOa for the mixture of 60% He and 40% Ar. For the elongation after fracture the best values, about 36%, were obtained for pure gases. As a main conclusion, we can say that arc welding of copper is possible without loosing the mechanical and metallurgical properties of base metal. 6 refs

[en] The properties of the electroless nickel deposit mainly depends on the pH of the bath, the plating temperature, and the molar ratio of nickel to hypophosphite but they are also affected by its formulation and concentration of complexing and buffering agents. According to changing the concentration of triethanolamine and boric acid, phosphorous contents, microstructure, crystalline, hardness and wear resistance of deposits obtained from ammoniacal alkaline bath were investigated by EPMA, differential thermal analyser, X-ray diffractometer and wear tester. The results are follows; 1) Increasing concentration of triethanolamine in the bath, the deposit is slightly inclined to increase its phosphorous content(3.7%P). 2) In the as-plated state, the deposits are not crystallized state but they are thermally unstable phase, and they are crystallized with precipitating Ni₃P at 400 deg C. 3) The deposit containing 2.3% P has higher hardness value in the as plated and heat treated state at below 300 deg C than those of 3.7% phosphorous deposit (1090Hk). But in the case of heat treating at 400 deg C, the former has lower hardness value (1000Hk) than the latter and has remarkably Ni(III) orientation by heat treatment. 4) The 3.7% phosphorous deposit heat treated at 400 deg C has better wear resistance than hard chromium plating. (Author)

[en] The elastic properties of the graphite monocrystal, the role of internal characteristics (texture, porosity) on the mechanical behavior of carbons, effects caused by the gaseous environment and neutron irradiation, and the resistance of graphites to cyclic mechanical stresses are discussed

No abstract available

No abstract available