Advanced materials

Random thoughts

Nobel Laureate Sir George Paget Thompson said: “We have, for some time, labelled civilisations by the main materials they have used; The Stone Age, The Bronze Age and the Iron Age. A civilisation is both developed and limited by the materials at its disposal. Today, mankind lives on the boundary line of the Iron Age and a New Materials Age”.

We have now truly entered the Advanced Materials Age. The rapid and multi-dimensional growth of high-tech industries has continued to expand the role of materials. High-strength and high-temperature alloys, ceramics, composites and polymers are being developed to meet specific technical requirements. Recent technological advances – such as the space shuttle, optical fibres and personal computers – would not have been possible without the availability of sophisticated materials. Materials developed for high-tech use, with the passage of time, filter down to touch the everyday lives of the people.

I am writing this column on useful materials to provide information to the public. In this era of expanded industrialisation, we need to be more aware of the materials that are being developed, the modern analytical techniques involved in characterising them, their physical and mechanical properties, their oxidation and corrosion behaviour, the application of corrosion protective coatings and the processing of these materials by electron beams. The development of materials with superior properties cannot be perceived without an advanced analytical technique for their characterisation.

The abilities of modern analytical techniques can help us study even the minutest details of their microstructural features. For example, using an average scanning transmission microscope system, we can see individual atomic planes, identify the crystal structure of submicron size secondary particles and determine their chemistry.

A multitude of analytical techniques – involving X-ray, neutron and electron diffraction spectroscopy – are available to obtain qualitative and quantitative information about the crystal structure and crystal imperfections, the dislocation, the atomic sites in inter-metallic compounds, the magnitude of strain, the surface texture, the magnetic ordering, the microstructural refinement and the grain interaction of composites. These microstructural features of materials are being related to important mechanical and corrosion properties, which can further be used to predict the life of components in a given environment.

Non-destructive techniques (NDT) are being used for materials characterisation. In addition to the classical methods of NDT – such as X-ray diffraction, ultrasonic attenuation and radiography – some innovative NDT techniques are laser beam optical topography and electron acoustic imaging. The techniques of non-destructive material evaluation have grown to such an extent and their scope is increasing with such rapidity that it becomes increasingly difficult for an average investigator to make the best choice of a technique for a particular requirement. Efforts should be devoted in Pakistan industries to develop and improve techniques to monitor and control the quality of the materials being produced, stored and used.

It is important to mention fatigue, fracture and creep in this context. On a global scale, metal fatigue, fracture and creep have been studied extensively. Relatively recent efforts have been directed at understanding the damage occurring in composites and other non-metallic materials. In Pakistan, hardly any effort has been made to recognise the importance of a thorough understanding of fracture at the macroscopic and microscopic levels. Spreading such knowledge is crucial to avoid premature failures in the service life of equipment. In our efforts to evolve the economic designs of equipment and structure, we have not yet progressed enough to predict the fatigue life of engineering components.

In order to enter an era of high technology, we should advance ourselves in each and every field of science and technology. Other nations have established strong national programmes in science and technology while we have yet to set our science and technology priorities. It should be realised that we will stand nowhere in the battle of international competitiveness if we do not become aware of the needs of the present.

We should put more emphasis on engineering science. There should be a proper balance between research in traditional engineering sciences and the emerging engineering fields. We should use our engineers more effectively and become directly involved in educating them throughout the span of their careers. We should hold technical seminars and discussions at national and international levels.

Metallurgy in Pakistan has emerged from neglected isolation in the past into a hopeful future. Integrated metallurgical plants and complexes like the Pakistan Steel, the Precision Engineering Complex of Pakistan International Airlines, the Peoples Steel Mill, the Heavy Foundry and Forge, the Karachi Shipyard and Engineering Works, the Space and Upper Atmosphere Research Commission, the Pakistan Atomic Energy Commission and the Dr A Q Khan Research Laboratories are some of the major metallurgical industrial and research centres. They are sensitive to national demands and have responded to the country’s requirements.

After the nuclear tests, our achievements in the nuclear and ballistic missiles fields have been praised. There was some surprise over the fact that my doctorate degree was in metallurgical engineering. As a physical metallurgists, we had wide knowledge of engineering subjects as well as all aspects of physics, chemistry and mechanics. There was great joy among my fellow engineers when they learnt – especially when I stressed the fact that our programme owed a lot to the fact that I was an engineer.

Scientific inventions represent sophisticated technologies, which would not have been possible had metallurgists not invented advanced materials. Nothing can be made without a proper understanding of materials. Of all the factors involved in industrialisation – manpower, materials, machines, methods and money –materials and how they are shaped and used is the most important factor.

Materials stand out as a part of the natural world and are useful ingredients for mankind. There is a persistent need to probe materials and use them wisely. This is both a challenge and a responsibility. The challenge has been taken seriously by the governments of industrially developed countries and we should do the same.

Email: dr.a.quadeer.khan@gmail.com