The Hindu       26.12.2011

From waste to wealth and much more

Better power-to-weight ratio:At the production line in a car factory. Cars now have their entire body built of carbon fibre composites, an alternative to metals, prized by plane-makers for their lightweight malleability.— Photo: Reuters

Several indices represent the prosperity of a people. A reliable one will be the types of materials they use.

Materials can be classified in many ways. Traditional materials have been in use for centuries. Advanced materials are new ones or modified forms of traditional materials, which give superior performance in specific applications.

The quest for innovative materials is an unending process that beckons numerous researchers in diverse areas of science. Advanced materials lead to improved processes and products, which influence economic growth, environment, and quality of life. Digital communication, sophisticated cyber world, and nanotechnology are some of the applications that demand improved materials. Advanced materials are in the early stages of their lifecycle. So there is room for growth in their performance characteristics. Advanced materials strategy has a symbiotic relationship with modern manufacturing strategy — an instance of the shop floor and the laboratory complementing each other.

A premier institution that develops innovative technologies and products in the area of advanced materials is the Advanced Materials and Processes Research Institute (AMPRI), Bhopal-462 064; Web: www.ampri.res.in

It was started in 1981 as a Regional Research Laboratory under the Council of Scientific and Industrial Research in New Delhi. Later, it was moved to Bhopal. Its original strength had been in the area of metallurgy and materials science. The areas of research have been broadened to include:

Mineral processing

Environmental impact assessment

Water resource modelling

“Waste to wealth”

Problems related to agricultural, mining, sugar mill, and thermal power plant machinery

Health assessment

Improvement and failure analysis of engineering systems

Development of lightweight materials, components, products, and processes for the automobile sector

Finite element method simulation

The current activities of the AMPRI are in the following:

Lightweight materials

Nano-structured materials

“Waste to wealth”

CSIR-800

Lightweight materials

Metallic materials: Aluminium metal matrix composites, foam and magnesium alloys, and components thereof for different engineering applications.

Polymeric materials: Work in the areas of polymeric and functionally graded materials for various engineering applications. Material design and synthesis, property characterisation, component development, and demonstration of performance under actual working conditions. Material development includes particulate as well as fibre-reinforced composites (particulates are minute separate particles). A wide range from synthetic organic and inorganic fibres to natural fibres for reinforcement in thermoplastic as well as thermosetting resins. Functional fillers such as silicon carbide, teflon and ultra-high-molecular-weight polyethylene have been incorporated for better wear resistance. Low-cost materials for flooring from industrial wastes, such as red mud and fly ash.

Computer simulation, modelling and design: For material, process, and components, including die design and CAE-CAD-CAM integration. Also for forging, rolling, extrusion, sheet bending, deep drawing, spring back, hole flanging nozzle pullout, metal casting, structural optimisation, fracture mechanics, impact and penetration mechanics, thin film growth, nano-materials, and so on. Other areas of work include analysis of spring-back in sheet metal bending, simulation of porthole die extrusion, software development, mathematical modelling, and computer simulation.

Nanomaterials

Nanostructured materials: Good for use as engineering materials with improved characteristics in terms of mechanical, physical, thermal, and wear properties. Powder metallurgy and chemical routes are used for synthesising nanostructured materials.

Microfluidics: This is the handling of devices and processes that deal with volumes of fluid as small as nanolitres or picolitres. Chemical separation methods such as chromatography and electrophoresis are necessary for fast analysis of complex mixtures on a very small scale. Innovative methods for these are being evolved at the AMPRI. (Chromatography is a process in which a chemical mixture carried by a liquid or gas is separated into components as a result of differential distribution of the solutes as they flow around or over a stationary liquid or solid phase. Electrophoresis is a separation technique based on the mobility of ions in an electric field.)

Waste to wealth

Recovery from wastes: Removal of toxic heavy metal ions from aqueous solutions using substrate materials made from low-grade natural minerals. Development of glazing material from “drum filter cake,” which is a waste from the zinc industry.

Shielding materials: The application of high-energy electromagnetic radiations in medicine (X-ray and CT scanner rooms and establishments, gamma radiation therapy of cancer, etc.), and nuclear power plants poses challenges in terms of safety. Lead, though conventionally used as a radiation shielding material, is inherently toxic and does not provide effective shielding against neutron radiation. Concrete has been used as a shielding material against ã-ray radiation. But it is very thick and subject to corrosion from depleted uranium. All these point to the need for the development of non-toxic and eco-friendly radiation shielding materials. A novel process for making advanced new radiopac materials has been developed at AMPRI.

Wood substitute: Industrial wastes such as red mud, fly ash, jarosite (hydrous sulfate of potassium and iron), marble slurry dust, copper tailings, and natural fibres such as jute have been used as fillers for developing polymer composites. These have higher strength and greater resistance to corrosion than wood. They are insensitive to attack by termites and rodents. The new products have been used for door leaves, roofing sheets, panels, and furniture.

CSIR 800

Sisal fibre-based products and composites: Extensive work has been done in the area of building materials based on natural fibre. This aims at saving wood and replacing asbestos fibre that is likely to cause cancer. A Natural Fibre Composite Development Centre has also been established at the institute. Research work includes the development of a methodology for mechanical extraction of fibres from leaves, for fibre treatment, characterisation, and preparation of materials and products.