Enhancement of thermal,mechanical, ignition and damping response of magnesium using nano-ceria particles

Magnesium (Mg)-based nanocomposites owing to their low density and biocompatibility are being targeted for transportation and biomedical sectors. In order to support a sustainable environment, the prime aim of this study was to develop non-toxic magnesium-based nanocomposites for a wide spectrum of applications. To support this objective, cerium oxide nanoparticles (0.5?vol%, 1?vol%, and 1.5?vol%) reinforced Mg composites are developed in this study using blend-press-sinter powder metallurgy technique. The microstructural studies exhibited limited amounts of porosity in Mg and Mg-CeO₂ samples (< 1%). Increasing presence of CeO₂ nanoparticles (up to 1.5?vol%) led to a progressive increase in microhardness, dimensional stability, damping capacity and ignition resistance of magnesium. The compressive strengths increased with the increasing addition of the nanoparticles with a significant enhancement in the fracture strain (up to ~48%). Superior energy absorption was observed for all the composite samples prior to compressive fracture. Further, enhancement in thermal, mechanical and damping characteristics of pure Mg is correlated with microstructural changes due to the presence of the CeO₂ nanoparticles.     

Utilizing Low‐Cost Eggshell Particles to Enhance the Mechanical Response of Mg–2.5Zn Magnesium Alloy Matrix

The search for lightweight high‐performance materials is growing exponentially primarily due to ever‐increasing stricter environmental regulations and stringent service conditions. To cater to these requirements, the use of low‐cost reinforcements has been explored in the Mg matrix to develop Economically Conscious Magnesium (ECo–Mg) composites. In this study, eggshell particles (3, 5, and 7 wt%) reinforced Mg–Zn composites are synthesized using blend‐press‐sinter powder metallurgy technique. The results reveal that the addition of eggshell particles enhances microhardness, thermal stability, damping, and yield strength with an inappreciable change in the density. In particular, Mg2.5Zn7ES composite do not ignite till ≈750 °C. The overall combination of properties exhibited by Mg–Zn–ES composites exceeds many of currently used commercial alloys in the transportation sector. An attempt is made, in this study, to interrelate microstructure and properties and to study the viability of compression and ignition properties with a comparison to commercially used Mg alloys.

     

Enhancing thermal and mechanical response of aluminum using nanolength scale TiC ceramic reinforcement

In the present work, nano-sized titanium carbide (0.5, 1.0 and 1.5?vol%) reinforced aluminum (Al) metal matrix composites were synthesized by powder metallurgy incorporating microwave sintering and hot extrusion. Microstructural, mechanical and thermal properties of hot extruded unreinforced aluminum and titanium carbide (TiC) reinforced aluminum composites are presented in this paper. X-ray diffraction (XRD) patterns and scanning electron microcopy (SEM) images show the homogeneous distribution of TiC nanoparticles in the Al matrix. The tensile and compressive strengths of Al composites increased with the increase in TiC content, while the ductility decreased. The CTE of Al composite decreased with the progressive addition of hard TiC nanoparticles. Overall, hot extruded Al 1.5?vol% TiC nanocomposite exhibited the best combination of tensile, compressive, hardness and Young's modulus of 186?±?3?MPa, 416?±?4?MPa, 9.75?±?0.5?GPa and ~103?GPa, respectively. High tensile strength and good thermal stability exhibited by Al-TiC nanocomposites developed in this study show the potential for a variety of weight-critical engineering applications.     

Quality and reliability assessment of hardware and software during the total product life cycle

A major challenge for the computer industry is the need for the development and implementation of an engineering languge which provides continuous linkages and measurement between the customer and all engineering functions internal to the company. Such a language would allow information solution developers and information service providers to be able to continuously monitor the quality and reliability performance of integrated hardware and software products during the complete product life cycle. A quantitative engineering language needs to be developed to provide seamless and continuous linkages between the customer—the user of integrated computer systems—and all of the engineering development and manufacturing functions tasked with designing and building solutions which meet customer needs. A methodology is proposed which addresses this challenge by the implementation of two metrics: total defects per unit (TDU) and the annual rate of events (ARE). These two metrics can measure all hardware, software and computer integration events during the total product life cycle. A methodology is presented which provides a rigorous translation of the ARE metric, monitored at the customer site, into the traditional reliability metrics used by engineering and manufacturing. Algorithms are presented which directly translate AREs into mean time between failures (MTBF), mean time between parts replacement (MTBPR) and mean time between system interruptions (MTBSI). The ARE metric meets the customer requirement of being able to clearly focus on the reliability and availability performance of total systems as a result of hardware and software components, the user interface, and environmental factors. The paper discusses the development and application of integrated TDU and ARE metrics and shows how the total product life cycle quality and reliability of a complex integrated computer and communications solution can be efficiently monitored and managed for improvement during design, manufacturing, and installation performance in an integrated customer environment.