Dihydrazone-based dynamic covalent epoxy networks with high creep resistance, controlled degradability, and intrinsic antibacterial properties from bioresources

This work highlights the exploitation of the dihydrazone motif to build antibacterial covalent adaptable networks with no creep at ∼105 °C.

Recent Developments of Martensitic Heat-Resistant Steels for Ultra-Supercritical Power Plants

This paper provides a comprehensive review of developments and progress made in martensitic heat-resistant steels, especially, with the emphasis on strengthening mechanisms used in elevated temperatures. We desired to elucidate the correlation between high creep resistance at elevated temperatures and thermal stability of nano-sized particles precipitated from martensite matrix. Finally, future prospective strengthening methods for martensitic heat-resistant steels were discussed.

Development of a TiCp Reinforced Ni-Based Superalloy MMC, with High Creep Resistance and Reduced Weight

Ni-based superalloys, in both single and polycrystalline varieties, are extensively used in high pressure turbine blades. But contrary to single crystal variants, the polycrystalline forms present easier manufacturing and offer higher potential for improvement in metal matrix composites (MMCs). To benefit from this opportunity, an Inconel X-750 superalloy reinforced with TiC particles is proposed, having a polycrystalline microstructure and the possibility for weight reduction in turbine elements application. The metallic powder with an addition of 15 vol.% of 3.7 μmd TiC particles was prepared through low energy mixing, uniaxial pressing and sintering, followed by a triple heat treatment. The microstructure was analyzed with SEM and XRD techniques. Compressive creep tests were performed at 800 °C with 200 MPa, on both original and reinforced alloys. The study shows how the inclusion of a highly compatible particle reinforcement does not only improves the creep resistance, but also reduces the material weight, thus having potential to promote further reduction in the creep rate on turbine blades submitted to centripetal forces.

Effects of Thermal Heat Treatment Parameters on the Properties of WE43 Magnesium Alloy

The WE43 is a Mg-Y-Nd alloy that presents good mechanical properties and an high creep resistance. For these reasons currently is widely used in the aerospace and automotive industries. The setting of the right thermal heat treatment parameters plays a crucial role in determine the microstructure and consequently the mechanical properties of the alloy. With this in mind, the main goal of this work has been that to identify the optimal parameters to achieve a high impact resistance and at the same time, the most suitable choice, to reach also an important cost-saving solution, which is extremely important especially from the industrial point of view.

Investigation of Die Attach for SiC Power Device for 300°C Applications

The mechanical properties of die attach system SiC/Au-Ge/Au-Ni-Cu-Si3N4 using the eutectic Au-Ge solder (Teut = 356°C) were investigated in a temperature range up to 300°C. The as-resulting structure of the solder is observed to be lamellar with pockets of high concentration of Au close to the interfaces. The shear strength of joint decreases with temperature but, even at 300°C, its value is well higher than the IEC standard. The creep behavior of Au-Ge solder alloy was also investigated at 300°C for different strain levels. The creep curves show a high creep resistance even for high stress level.