Spark Plasma Sintering (SPS) of Multi-Principal Element Alloys of Copper-Niobium-Titanium-Di-Boride-Graphite, Investigation of Microstructures, and Properties

A near-equiatomic multi-principal element alloy of Cu40Nb30(TiB2)20C10 with both nano-particle size (14 nm) and micron-particle sizes (−44 µm) of Nb was designed and made via the spark plasma sintering technique at two different sintered temperatures of 650 °C and 700 °C with other SPS parameters being constant. The sintering mode, microstructures, microhardness, density, relative density, wear behavior, and corrosion properties of the alloys were investigated and compared to ascertain the best for aerospace applications. The SPS technique was applied to produce the tested samples in this study. The results showed that the alloys with nano-particles of Nb sintered faster, with the lowest wear rate, and their microstructure shows a dendritic configuration with the existence of graphite-rich and niobium-rich nano-segregations in the inter-dendritic areas with the lowest coefficient of friction, Cu-NbTiB2C with nano-particles of Nb sintered at 650 °C recorded the highest microhardness value (786.03 HV0.2), and CuNbTiB2C with micro-particles of Nb sintered at 700 °C exhibited the best anti-corrosion characteristics in a sulphuric acid environment. The results obtained in this study correspond to the requirements for high-performance engineering materials, which will make the novel materials relevant in the aerospace industry

Spark Plasma Sintering of Copper-Niobium-Graphite Composites, and the Investigations of Their Microstructure and Properties

The microstructures and properties of ternary copper-niobium-graphite (Cu-Nb(nano)10-C4, and Cu-Nb(micron)10-C4) composites produced via spark plasma sintering (SPS) technique have been investigated for their potential use as electrical connection materials at high-temperature application. Nowadays, there is much activity in the development of such material all over the world. This study was aimed to compare the effect of adding the nano and micron particles sizes of Nb powders in the microstructures and properties of Cu-Nb-C composites sintered at 700 and 650 °C temperatures. The investigated materials have been produced via the SPS method. The microstructures were observed by electron microscopy technique, the wear test was observed by Anton-Paar TRB3 tribometer, thermal diffusivity was observed by LFA427 NETzschlaser flash device within the temperature of 100–900 °C, and the corrosion test was performed by potentiodynamic polarization. The discoveries have been presented in the manuscript and were discussed with reference to the microstructure development, the composite with nanoparticles sintered at 650 °C displayed closed thermal stabilities as temperature increased, and it recorded a low coefficient of friction and suitable corrosion resistance, which correspond to requirements for electrical contacting materials. The SPS method of production of the composites caused initial microstructure refinement and improved the properties of the composites

Prospects of nanostructured composite materials for energy harvesting and storage

International audienceIn the 21st century, energy demand and the attendant environmental degradation, are among the most challenging issues. The concern is due to the high dependence, globally on fossil fuels as a form of energy generation. Over 6.5 billion people worldwide require approximately 13 Terawatts of energy for their day-to-day needs. In order to achieve the required energy demand, there is a need to diversify into other forms of energy; in this case, renewable energy. In so doing, there is the need to study, extensively, alternative materials and sources needed for energy generation, storage, distribution and application. There has been a significant advancement in energy generation, conversion and storage, such as fuel cells and solar cells, photovoltaic cells, supercapacitors, batteries, etc. The emergence of nanostructured and composite materials has resulted in some significant contributions towards the improvement in the energy industry development. Renewable energy, such as wind and solar energies, depend considerably, on the environmental conditions, which are not always stable. Hence, in order to harness the energy from these sources and to adequately store such energy, there is a need for a high-performance energy conversion and storage system for the energy generation process. In this regard, carbon nanomaterials, metallic sulphides, titanium oxide and many other nanostructured materials have been studied, to a large extent, for energy conversions and storage devices. The importance of nanostructured and composite materials has shown, from researches, to resolve the issues surrounding energy from generation to storage

Spark Plasma Sintering (SPS) of Multi-Principal Element Alloys of Copper-Niobium-Titanium-Di-Boride-Graphite, Investigation of Microstructures, and Properties

A near-equiatomic multi-principal element alloy of Cu40Nb30(TiB2)20C10 with both nano-particle size (14 nm) and micron-particle sizes (−44 µm) of Nb was designed and made via the spark plasma sintering technique at two different sintered temperatures of 650 °C and 700 °C with other SPS parameters being constant. The sintering mode, microstructures, microhardness, density, relative density, wear behavior, and corrosion properties of the alloys were investigated and compared to ascertain the best for aerospace applications. The SPS technique was applied to produce the tested samples in this study. The results showed that the alloys with nano-particles of Nb sintered faster, with the lowest wear rate, and their microstructure shows a dendritic configuration with the existence of graphite-rich and niobium-rich nano-segregations in the inter-dendritic areas with the lowest coefficient of friction, Cu-NbTiB2C with nano-particles of Nb sintered at 650 °C recorded the highest microhardness value (786.03 HV0.2), and CuNbTiB2C with micro-particles of Nb sintered at 700 °C exhibited the best anti-corrosion characteristics in a sulphuric acid environment. The results obtained in this study correspond to the requirements for high-performance engineering materials, which will make the novel materials relevant in the aerospace industry

Development and application of nanocomposite for sustainable rail vehicle with low environmental footprint

International audienceIn many developing countries, society is characterized by increasing population growth, urbanization, and industrialization, which have an effect on the environment. The growing population demands improved and safe ways of transporting people, goods, and services from one point to another at a minimal impact on the environment. The high demand for energy is another concern for any developing nation, most especially for a country where rail cars are powered by electricity. The weight of the rail cars contributes to the total carbon dioxide (CO2) emission. In order to reduce the energy demand, CO2 emission and increase return on investment, there is a need for improved composite materials. The current research focused on the production of composites made from polypropylene, sisal fiber and nanoparticle. The fiber was treated and the content was varied from 10, 20, 30 and 40 wt%, while the clay and the compatibilizer were kept constant at 3 and 5 wt% respectively. There was an improvement in the mechanical and thermal properties of the composites. Based on the improvement observed, the material can be used for the interior component of the rail vehicle

Need for Sustainable Packaging: An Overview

Packaging materials are a significant part of our lives due to their daily usage at grocery stores, supermarkets, restaurants, pharmaceuticals, etc. Packaging plays an important role in ensuring that the products are preserved during handling, transporting, and storage. Similarly, it helps to maintain and prolong the shelf life of products. These materials are used for packaging meats, poultry and seafood products, food and beverages, cosmetics, and pharmaceutical products. Several applications of packaging materials have been discussed extensively, with little discussion on their end of life and continuous availability without impacting the environment. This study presents the need for sustainable packaging as a result of growing demands and the environmental impact of packaging materials after use. This study also presents the importance, types, and applications of packaging materials. Based on the findings of this study, sustainable packaging is made possible by using bio-based and recyclable materials. These materials contribute a great deal to protecting and ensuring a sustainable environment

A review on Africa energy supply through renewable energy production: Nigeria, Cameroon, Ghana and South Africa as a case study

International audienceIn this study, the importance of renewable energy as a complement to meeting the energy demand in Africa was investigated. In most African countries, the larger percentage of power generation is from fossil fuel-based energy sources, and without a doubt, this can be complemented with renewable energy to meet the demand per country and the global interest on climate change. Nigeria, Cameroon, Ghana and South Africa are among the leading African countries that are blessed with an abundance of renewable energy resources, which have the potentials to improve their respective energy generation potentials; thereby, contributing to the socio-economic growth, promote industrialization, reduce global warming and create green jobs. Despite the abundant renewable energy sources in these countries, they are yet to fully harness the potentials, therefore, resulting in their deficiencies in contributing to the electrical power generation per country. The bulk of the problems associated with renewable energy in African countries are: little interest and lopsided policy on renewable energy, enforcing existing policies, high renewable energy tariff, and lack of adequate infrastructure. The current study discusses the ways by which conscious decisions and policy of governments, alongside the stakeholders’ dedication can ensure sustainable energy supplies. Based on the findings of the study, renewable energy-based power generation can greatly reduce greenhouse gases. Also, subsidizing the tariff levied on renewable can promote energy generation leading to job creation through energy generation from renewable resources