Microstructure and mechanical properties of rolled Mg–Gd–Zn–Zr–Ag–Al–Li alloys

The microstructural evolution and mechanical properties of hot rolled Mg-12Gd-1Zn-0.5Zr-0.5Ag (in wt.%) (MGZKA) alloys, with and without Al and Li additions, were investigated in this study. The Al and Li-containing alloys achieved excellent overall mechanical properties, especially MGZKA-6Al5Li alloy with a high elastic modulus of 52.2 GPa and a good plasticity of 15%. Compared with Al and Li-free MGZKA alloy, the fragmented Al2Gd and nanoscale Al2Li3 phases with high modulus are observed in Al and Li-containing MGZKA-4Al3Li and MGZKA-6Al5Li alloys, which contribute to the overall elastic modulus of the alloys. The dynamic recrystallization regions of Al and Li-containing alloys increased while c/a ratio reduced, leading to the weakened texture. The activation of non-basal slip in Al and Li-containing alloys is closely related to the fine grains and weakened texture, which jointly promote the plasticity of Al and Li-containing alloys.

Influence of elastic modulus of intraradicular posts on the fracture load of roots restored with full crowns

Objective This study aimed to evaluate the fracture load and displacement of roots restored with posts of different elastic modulus. Material and method Thirty-six replicas of epoxy resin mixed with glass microfibers were made from an endodontically-treated human premolar root prepared to a length of 12 mm with a custom drill, leaving the apical 4 mm unprepared. Replicas were randomly restored with (n = 12): FP-LM (fiber post with low elastic modulus– 50 GPa), FP-HM (fiber post with high elastic modulus – 67 GPa) and MP (metallic post – 208 GPa), using self-curing adhesive and dual resin cement. Cores were built up with composite resin and metallic crowns were cemented in all the roots with self-adhesive resin cement with self-curing mode. Specimens were subjected to a fracture load test (45° inclination/0.5 mm/min) and displacement was registered at 100 N. Result One-way ANOVA showed that elastic modulus of the post did not affect the fracture load means (p = 0.203) (FP-LM: 237.4 ± 65.11 N; FP-HM: 236.7 ± 92.85 N; MP: 295.8 ± 108.7 N) but was statistically significant for the displacement (p < 0.00): Tukey’s test showed that FP-LM displacement mean (0.81 ± 0.15 mm) was significantly higher than those for FP-HM (0.46 ± 0.26 mm; p = 0.00) and MP (0.62 ± 0.07 mm; p = 0.04). Conclusion Posts with different elastic modulus exhibit similar fracture loads, but a lower displacement is achieved when fiber posts with a high elastic modulus and metallic posts are used.

Quasielastic neutron scattering study of microscopic dynamics in polybutadiene reinforced with an unsaturated carboxylate

The dynamics of BR is heterogeneous in ZDA/BR and a rigid network-like structure is responsible for its high elastic modulus.

A high modulus hydrogel obtained from hydrogen bond reconstruction and its application in vibration damper

The cross-linking network of the hydrogel can be rearranged by evaporation-swelling treatment, the obtained hydrogel possesses an excellent vibration absorption ability and high elastic modulus.

Electro-active elastomer composites based on doped titanium dioxide

The TiO2-Acac/PDMS elastomer conserves a high elastic modulus change (ΔG′) after cross-linking and achieves ΔG′ higher than 500 kPa for an applied electric field of 2 kV mm−1.