Quo Vadis Globalization

America Uses Indian Scientist To Get Russian Defence Technology

Squadron Leader B.G. Prakash

Introduction

A molten drop of metal is made to ‘levitate’ at the top of a magnetic field due to an electrical current that acts on it as it drops while an opposing magnetic field, developed by a conical coil configuration pushes the molten drop from the opposite direction. This is an old technology but with an innovative application. Pressurized gas disintegrates the molten drop into tiny droplets to be deposited as powder. It is a step in the process to produce metallic powder of particle sizes in the region of 100 nanometer and less. One nanometer is one thousandth of a micron. In general, this is called ‘nano-powder’ drawn out of nano-technology with its base in nano-science - the buzz-word. After a few years of research, scientists in the United States of America became aware of ‘feelers’ coming through their intelligence agencies that the Russians had progressed further in a particular field of this technology - in a process to make nano-powder. Nano-technology having started first, in Russia.

By then, the erstwhile USSR had disintegrated - not to nano-levels, that is. The economic condition in the newly formed nations was generally poor, but varied from country to country. One way to beat the economy was to sell or part with some technologies that some Russians had developed, for a price. Initially, what was on offer was fruitful to buyers. USA was an active recipient of such technologies. Soon, it came to light that several ‘fakes’ had joined the bandwagon. Some ‘black boxes’ were sold for millions, which when analyzed, were found to contain technology at a much lower level worthy of a much lesser price. Some Defence Research and Development Organization laboratories in India experienced similar surprises.

Reverse Body-Shopping

When the ‘Levitation Melting Process’ came to light, the US authorities wanted to test the claim before deciding on the offer. After some brain storming, it was decided to send an engineer with adequate background and experience to get trained at the Russian premises, instead of buying out an unsubstantiated technology. Simply put, it was ‘body-shopping’ in reverse - a receptive mind in the body was sent to get trained or get value added, on site, for a fee.

International psychology was applied; in 1994 an Indian national - who now, has a few patents to his credit - working on this technology in a USA based company, Materials Modification Inc. (MMI) was chosen to be sent to Russia. The prevalent rapport that Russia and India enjoyed was the facilitator and was to be exploited. The Indian engineer spent a month under training at the Institute of New Chemical Physics, Cherneglovka, a place 20 kilometers from Moscow.

The result was fruitful, the Levitation Melting Process is now set up in the USA to produce nano-powders of Iron, Cobalt, Nickel, Molybdenum, Tungsten, Titanium as well as some metal alloy such as iron-copper. Physical properties of nano-material correspond neither to those of the free atoms and molecules making up the particle nor to those of the bulk solid of the same chemical composition. 

MMI was actively involved in being an out source as a manufacturing unit for research for the US Army. Between 1996 and 1999, projectiles of conical shape of size two inches in length and one inch in diameter made of nano-material were on trial and test. These were used in anti tank ammunition. Nano-composites were also tried. After promising results in the first tests, the US Army research establishment is now conducting more trials.

USA possesses stronger ammo

The projectiles ejected from field guns, rockets and cannons are expected to penetrate and damage the hard surface of a target such as an armored vehicle or a tank. The tip of the projectile gets an added strength due to the nano-materials, to develop a ‘mushroom’ effect - while penetrating - immediately after the initial impact. This is unlike the normal flat face that a projectile gets otherwise. The mushroom effect enables it to penetrate further to cause more damage. By using nano-powder based tips, for the same weight and thrust, more damage can be caused to the enemy target. The phenomenon is called ‘high strain deformat’.

Orders for projectiles of varying combinations of Nano-alloys with actual density approaching 95 per cent of the theoretical density were placed with this firm, and the firm quickly delivered. During the Gulf War in 1991 each Stealth Fighter F-117A carried two laser guided 2,000-pound ‘smart bombs’ designed to penetrate enemy bunkers before exploding - possibly, then, they had a chance to experiment. Stealth was on trial, anyway. Nano-material was probably used in the ‘nose’ of the bombs. The effort was repeated in Afghanistan in 2001; only the US knows the exact results.

In this evolving nano-technology, choice of a process depends on the desired particle size, shape, distribution of the particles, its purity, structure, availability of raw material, the desired production rate and more importantly, the cost of production. One kilogram of nano-powder of iron can cost US $ 1,500! Cost vis-à-vis performance is the criterion. Apart from the Levitation Melting Process, there are others too - as Ball Milling or Mechanical Attrition, Laser Ablation, Aerosol technique, Sol-Gel or chemical precipitation technique, Vapor condensation & sputtering, Direct Current plasma, Microwave plasma and Radio Frequency plasma to name a few. It is perhaps grudgingly acknowledged that the Russians had a lead in nano-technology.

Indian Scenario

Nano technology is at its infancy in India. Dr. V.S. Ramamurthy, Secretary, Department of Science and Technology attended a specially arranged presentation at the start of this millennium, in January 2001. Advanced Research Center for Powder Metallurgy and New Materials under the auspices of Defence Metallurgical Research Laboratory came into existence at Hyderabad, the same year. Prof C.N.R. Rao, former director, Indian Institute of Science, along with two colleagues, is giving a thrust to nano-technology at the Jawaharlal Nehru Center for Advanced Scientific Research at Bangalore.

Possible Applications in Defence

Nose Cone of Lca

The nose cone of the Indian Light Combat Aircraft, as fabricated presently, can withstand 288 degrees Celsius. Designers at the Aeronautical Development Agency and at the National Aerospace Laboratory, which is under the Council of Scientific and Industrial Research, are not satisfied with the Graphite Fiber-Polymer based Nose Cone of the LCA. They want Thermal Protection System (TPS) to avoid melting at a higher temperature. A small nozzle from the engine bay takes the hot air internally towards the nose cone to heat it up to initiate de-icing, which is needed. This is a prevalent technique.

Inducting nano-material into polymer can improve conductivity. Researchers want enhanced conductivity at the surface of the nose cone to have a better ratio between the inside and the outside temperatures, when the LCA is in flight. The polymer composite material is not at the level of nano-sized grain. Research at the Gas Turbine Research Establishment (GTRE), aims to adapt nano-sized material to improve the specifications of the nose cone.

TBC on the `Kaveri’ engine for the LCA

The titanium blades fitted on to the hub of the Kaveri Jet engine built for the LCA - on the test bed at GTRE - are not made using nano-technology. Cooling channels carrying air are imbedded in the airfoil shaped blades made of Nickel-Chromium-Aluminum ‘super alloy’. This withstands a temperature of 1,000 degrees Celsius. When subjected to temperatures beyond this, dimensions of the blade may change. The Kaveri engine is to get ‘thrust vector’ technology in the future.    

A Thermal Barrier Coat (TBC) of ‘micron-size’ ceramic on the surface of the blade can insulate the other side of the blade to remain at a temperature of about 800 degrees Celsius. The coat can be of a thickness of 15 micron. If nano-sized ceramic particles are used, the thermal barrier coat can be only five micron thick. Jet pipe temperature rises even up to 1,500 degrees Celsius. Higher jet pipe temperature can give more thrust. In other words successful adaptation of nano-technology helps to increase the thrust of the jet engine, for the same weight.

Turbine blades for aero-engines are no longer made of ordinary sheets of super alloys. A crystal can be grown into a single blade - it is a single crystal blade. All blades in a turbine can be of single crystal technology. If these are coated with nano material, the blades can withstand still higher temperatures, though no TBC is needed. It is possible that the vibration due to the turbine in motion is also less. Recently, Russia has agreed to let Hindustan Aeronautics Limited manufacture 140 of the two-seat fighter aircraft SU-30 MKI - it is claimed that along with the infrastructure, the single crystal turbine blade technology is being transferred to India.

The technology that is followed at Rolls Royce, Pratt & Whitney and General Electric jet engines, for example, is unique, when turbine blades are embedded into the hub or shaft of the aircraft jet engine. Though the cross section of the airfoil shaped turbine blade is a time-tested limit, it ensures much less vibration and reduced loss of power. Smart Technology for gas turbine engine is actively being pursued. Embedded sensors will get into actuator and control surfaces soon.

As the Indian LCA dovetails into the advanced LCA-2, Kota Harinarayana, Programme Director, ADA says it is bound to become ‘smart’. He was delivering the first presentation at the 10th anniversary of the Society of Indian Aerospace Technologies and Industries at Bangalore at the end of April 2002. Aerodynamic improvement for ‘deck landing’ will arrive with the ‘Vortex Plate’ that will replace the wing leading edge of the airframe. It will be a thrust vector based ‘EVCON’. Nano-materials will play a part. Kota laughs at the concept of a tail plane; he might end up removing it from the LCA.

Curing Time in the LCA

Because of ultra fine phase dimension involved, nano-composites exhibit new and improved properties in comparison with micro and macro composites. A combination of an organic binding ‘matrix’ and an inorganic ‘reinforcement’ is called ‘composite’. More than two components are possible in a composite structure. The carbon, polymer composite that goes into the airframe of LCA is set on moulds and is allowed to cure or dry - for some parts, at the room temperature, for some at 100 degree Celsius or more - for 24 or 48 hours. Reliability of mechanical property depends upon uniformity of cure. Electron Beam cure is a new technology. It improves cure and reduces time and cost. Nano-powder is not in use, yet. With nano-metallic and alloy powder mix, more reliable parts of the airframe can be manufactured faster.

SARAS

In composite technology, several individual parts of the airframe are integrated and the number of riveting points reduces. With cold extrusion, and with nano-material around the hole for riveting, development and growth of cracks from the holes can be advantageously reduced. The advanced composite section at NAL is experimenting on curing methods to manufacture parts for the LCA and the SARAS, the 15-seat All Composite Light Transport Aircraft - the prototype is set to fly this year.

Stronger Barrels

The inner core of the barrel of field guns - such as the Bofors - and other cannons and rocket launchers wear out by repeated wear and tear. If the inside surface of the barrel can be augmented with axial linings made of nano-powder, the life of the barrel is increased and the accuracy of the weapon system increases too.

VIPs to wear `Nano’

Bullet proof vests or body armor are needed on the battle field as well as for protecting VVIPs. Vests made of nano powder can be lighter in weight and more impervious. Strength is inversely proportional to the square root of the grain size of the nano material. Denser the molecules stronger the particle. Smaller the size of the nano-particle, stronger is the material. Smaller are the grains, stronger is the metal part made of the powder.                                                                                                                   

Japan is pursuing nano-technology in the field of high speed and laboratories for nano-electronic material have been set up. With miniaturization as their forte, can they cross the theoretical maximum speed limit? Automobile piston-head withstands higher temperature with TBC, but for which the piston may seize. European nations are engaged in research in medicine to find more sensitive sensors and in the use of nano-technology. Satellite and space technology looks at nano-science voraciously. Solar array and high-energy battery - indispensable in a satellite - can evolve out of nano-technology. TPS in launch vehicle is actively being studied.

At one time, Ceramic was touted as a replacement for metals. It is a heat shield and a cutting tool for machining super alloy. Ceramic with ultra fine grains - as in nano-stage - becomes more fracture resistant, more ductile, tougher. Eventually it develops Super plasticity - a property to get elongated to many times the original length - and can be stamped into thin sheets as well.

German Initiative

Incandescent lamps that use a filament to glow and produce light have a limitation. If the filament can be made of nano-powder, it can withstand higher temperature to produce more light and the life of a rated filament increases. It becomes more rugged. The raw material is the block of tungsten alloy from which the filament wire is drawn. Hitherto existing processes take four hours to make the block. Plasma sintering technology reduces it to fifteen minutes. German technologists got wind of the efforts at MMI, USA and asked for the transfer of technology, which was refused. There was no embargo on the sale of the manufacturing equipment with the technology; the Germans bought it. “Ruggedised” incandescent lighting is a support for armies on the move too.

Nano for Stealth at Radar Frequency

The Stealth Aircraft F-117A used in the Gulf War and B-2 of the US Air Force have been making news - as late as in October last in Afghanistan. The Chief Scientist at the Moscow Institute of Radio Engineering, Pyotr Ufimtsev  showed in the mid sixties how to create computer software to accurately calculate the radar cross section of a given configuration in two dimensions. Triangle shaped plates showed very low radar cross section. Radar engineer Denys Overholser at the Lockheed Skunk Works studied this. The ugly “shape of triangles - wedges - concept” all over the airframe by Denys - who called it a Hopeless Diamond - came up and was executed by Dick Cantrell in 1975. The F-117A was born then - the first machine with straight lines and flat surfaces to fly. A radar beam is an electromagnetic (EM) field, and the amount of energy reflected back from the target determines its visibility on radar. For field trials, a model was mounted on a 12 foot pole. The radar, 1,500 feet away could not pick up the model - which, apparently, scattered impinging radar energy or disbursed it in random directions - but picked up a crow that sat on it.

Further, Ferrite based ‘radar absorbing material’ (RAM) that converts radar energy into heat is used at strategic locations on the airframe. As the radar beam strikes the ferrite, the energy makes the molecules oscillate creating thermal energy. As the EM energy radiated from radar, impinges on the airplane, the density of the reflection is not sufficient. The fan shaped receiving lobe does not pick up enough for its receiver to display a clear blip on the radar screen. To identify the airplane becomes difficult and tracking on a radar screen is more difficult. In the final design, engineers addressed infrared, visible, contrail or vapour trail, smoke, acoustic parameters too, which are ‘observable’ in addition to detection by radar. The time needed for detection by radar significantly increased. The B-2, which is designed for more ‘stores’, carries them within its belly to conform to the external three-dimensional shape to be stealthy. It is speculated that the ‘stealth technology improved by nano material’ might be within the grasp of Russia too.

The Plane wave front of EM radar radiation can be scattered by an object whose characteristic dimension is much less than the wavelength of the incident wave. A nano-size sphere can scatter radar waves of micron size wavelength. Nano-powder in a coat of nanometer thickness on the surface of the airframe may help. Otherwise, airframes made of composite material have low reflection coefficient and offer low radar signature. The shape of each grain can be spherical, cubical, tetrahedral or can be rhombohedral. The scope for further research opens up in trying out powder of grains with different crystalline shapes.

Kota says that the design of the fifth generation aircraft will be ‘stealth driven’.  A cruise missile such as BrahMos, which performed successfully for the second time on 28th April 2002 can become stealthy. Deep Penetration Strike Aircraft and Medium Range Combat Aircraft are at conceptual stage. Advanced sensor integration with super cruise configuration will take over in the future. India had missed acquiring manufacture technology for Integrated Circuit Chip grade Silicon - only Dr Homi Bhabha dared to dream it four decades ago - she can now afford to ignore ‘nano’ only at her peril. 

This article appeared in the Indian Defence Review and has been reproduced here with permission from Lancer Publishers.