BrahMos, AeroClub Industrial Visit by AeroClub IIST

Industrial Visit to BRAHMOS AEROSPACE TRIVANDRUM LIMITED 20 th S e p t e m b e r 2 0 1 4

INDIAN INSTITUTE OF SPACE SCIENCE AND TECHNOLOGY

INDEX

NO. 1

CONTENT FOREWORD

PAGE 2

BrahMos AT A GLANCE

NDT

PRECISION AND GENERAL MACHINE SHOP

QUALITY CONTROL

SURFACE TREATMENT

APPENDIX

11 15

FOREWORD The AeroClub, Indian Institute of Space Science and Technology (IIST) organized an Industrial visit to BrahMos Aerospace Trivandrum Ltd. (BATL), on 20th September, 2014 for members of the Club. Total 19 student members along with 4 faculty members joined this industrial visit. The visit was organized with the prior permission and guidance of Dr. Praveen Krishna, Assistant Professor, IIST. Prof. Pradeep Kumar, Prof. Deepu, Prof. B.R. Vinoth and Prof. Satheesh accompanied us with this industrial visit. We would like to express our deepest appreciation to Mr. Rajeev Madhvan who continually and convincingly conveyed the spirit of adventure and guided us throughout the visit explained us every part of BrahMos. We would like to thank our Professors and Institute without whom the visit wouldn`t have been a possibility at the first instance.

BrahMos AT A GLANCE According to the late Edwin Starr, war is good for absolutely nothing. They create havoc and loss to mankind on a large scale. Wars put pressure on the resources of the country making them work hard to juice out the maximum from even the little that they possess which tends to accelerate technological development to adapt tools for the purpose of solving specific military needs. During the Persian Gulf war, cruise missiles emerged as a key innovation which led India to look forward in the direction of having its own Cruise missile. As a result in February 1998, the then President of India A. P. J. Abdul Kalam and Deputy Defence Minister of Russia N.V. Mikhailov signed an intergovernmental agreement in Moscow to establish BrahMos Aerospace for producing the BrahMos missiles. The missile is named after two rivers, Brahmaputra of India and Moskva of Russia. First of all, what is a Cruise missile? It is a guided missile that carries an explosive payload and uses a lifting wing and a propulsion system, usually a jet engine to allow sustained flight. The Defence Research and Development Organization (DRDO) of India and the Federal State Unitary Enterprise NPO Mashinostroyenia (NPOM) of Russia have together formed the BrahMos Aerospace Private Limited under BrahMos Aerospace. BrahMos Aerospace production centre first started at Hyderabad in Andra Pradesh. In 2007, BrahMos Aerospace acquired Kerala Hitech Industries Limited at Thiruvananthapuram in Kerala and converted it into BrahMos Aerospace Trivandrum Limited which made it into the second missile making unit for a world-class missile facility with system integration and testing. It is an AS9100 company, highest certificate given to any Aerospace industry and is the biggest airborne launcher manufacturer in India. The symbol for BrahMos Aerospace Trivandrum Ltd. shows that the missile is so powerful that it can even break ‘Shivling’; Shivling depicting the epitome of power as per Indian mythology. The missile can be configured for land, sea and aerial platforms. The technical specifications include: Maximum range -290km Maximum velocity Mach -2.5 – 2.8 Warhead -300kg Weight -3000kg Length -8.4m Diameter -0.6m Unit cost -US$ 2.73 million BrahMos is powered by a two-stage propulsion system. A solid propellant booster provides the initial acceleration and then the liquid-fuelled ramjet system helps it in reaching supersonic cruise speed. The air-breathing ramjet propulsion is more fuel-efficient in comparison with conventional rocket propulsion which provides the BrahMos with a longer range over similar missiles powered by rocket propulsion. The missile follows ‘Fire and forget’ principle of operation i.e. it has inbuilt inertial sensors like gyroscopes and accelerometers, GPS and radar which requires no guidance system after being launched.

4 It has the capability of attacking surface targets as low as 10 meters in altitude to as high as 14000 meters. The first BrahMos missile was test fired from the integrated test range at Chandipur in Orissa Coast in June 2001. After that, missile has been numerous times. In 2004 and 2007, the land based BrahMos block-1 was tested for Indian army in Pokhran, Rajasthan and then was inducted into army on June 21, 2007. In 2008, BrahMos Aerospace acquired Indian state-owned firm Keltec to manufacture and integrate BrahMos components and missile systems. This was necessary to meet the increased orders received from the Indian Army and Navy. Block II, with advanced supersonic dive manoeuvrability, has also been developed and was tested in September 2010 from the Interim test range at Chandipur, Orissa. In December 2010, the BrahMos block-III+ version was successfully test-fired from the integrated test range at Chandipur, off the Orissa Coast, India. Brahmos 2, a hypersonic cruise missile with a speed of Mach 7, is under development. Its range is expected to be 290 meters; keeping in mind that Missile Technology Control Regime prohibits Russia from helping us in developing missiles with ranges above 300 kms. BrahMos Aerospace has developed a universal vertical launcher module (UVLM) for the shipbased BrahMos N1 missile. The UVLM can launch up to eight missiles to destroy a group of warships featuring modern anti-missile defence systems. An aircraft-launched variant (BrahMos A) is currently being configured for the Sukhoi SU-30MKI aircraft of the Indian Air Force (IAF). It features a smaller booster and additional tail fins for greater stability during launch.

NDT Non-destructive testing (NDT) is a wide group of analysis techniques used in science and industry to evaluate the properties of a material, component or system without causing damage. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research. Common NDT methods include ultrasonic, magnetic-particle, liquid penetrant, radiographic, remote visual inspection (RVI), eddy-current testing, and low coherence interferometry. NDT is commonly used in forensic engineering, mechanical engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, medicine, and art. BrahMos Weld verification by X ray Radiography After welding, visual inspection can detect a variety of surface flaws, including cracks, porosity and unfilled craters, regardless of subsequent inspection procedures. Dimensional variances, warpage and appearance flaws, as well as weld size characteristics, can be evaluated. Moreover for precise flaw detection, Radiography (X-ray) is one of the most important, versatile and widely accepted of all the non-destructive examination methods - Fig. 1. X-ray is used to determine internal soundness of the welds.

Fig 1. Radiography Radiography is based on the ability of X-rays and gamma rays to pass through metal and other materials opaque to ordinary light, and produce photographic records of the transmitted radiant energy. All materials will absorb known amounts of this radiant energy and, therefore, X-rays and gamma rays can be used to show discontinuities and inclusions within the opaque material. The permanent film record of the internal conditions will show the basic information by which weld soundness and be determined.

6 When X-rays or gamma rays are directed at a section of weldment , not all of the radiation passes are through the metal. Different materials, depending on their density, thickness and atomic number, will absorb different wavelengths of radiant energy. The degree to which the different materials absorb these rays determines the intensity of the rays penetrating through the material. When variations of these rays are recorded, a means of seeing inside the material is available. The image on a developed photo-sensitized film is known as a radiograph. Thicker areas of the specimen or higher density material (tungsten inclusion), will absorb more radiation and their corresponding areas on the radiograph will be lighter Radiographic images are not always easy to interpret. Film handling marks and streaks, fog and spots caused by developing errors may make it difficult to identify defects. Such film artifacts may mask weld discontinuities. Surface defects will show up on the film and must be recognized. Because the angle of exposure will also influence the radiograph, it is difficult or impossible to analyze fillet welds by this method. Because a radiograph compresses all the defects that occur throughout the thickness of the weld into one plane, it tends to give an exaggerated impression of scattered type defects such as porosity or inclusions. Inspection is done using X-rays and gamma rays as a penetrating medium, and densitized film as a recording medium, to obtain a photographic record of internal quality of weld of the separate parts of the pressure vessels. Generally, defects in welds consist either of a void in the weld metal itself or an inclusion (tungsten in the weld strip shown to us) that differs in density from the surrounding weld metal. Radiographic equipment produces radiation that can be harmful to body tissue in excessive amounts, safety precautions like proper uniform and isolation of the room with lead accessories is a must. All instructions are followed carefully to achieve satisfactory results. Only personnel who are trained in radiation safety and qualified as industrial radiographers are be permitted to do radiographic testing.

PRECISION AND GENERAL MACHINING Precision machining is a process where material is removed from a component to a very high tolerance. Precision Instrument Machine Shop is a full-service machine shop specializing in the custom design and fabrication of mechanical equipment. The temperature of the room is kept at 20 degree celsius so that variation related to temperature does not affect the finish. Precision machines use a cutter and can be solid cutters such as tungsten carbide, cobalt or HSS. Also Watercutters were used which are very accurate and use extremely high pressure water. There are precision type lathes, drilling and boring machines, grinders, gear cutters, and milling machines. Precision machine tools are classified as machine tools of increased precision ( class P), high precision ( class H), superhigh precision(class A), and highest precision ( class S). Precision machine tools make it possible to produce articles of grade of fit 11, with geometrically regular surfaces, precisely aligned axes, and low surface roughness. In the Precision machining room, there are around 26 CNC machines which allows to machine extremely small and accurate features at a sub-millimeter scale. 3 axis as well as 5 axis machines are available. Drill bits with size as low as 2 mm are used to machine the process. There are continuous path controllers as well as point to point path controllers helping in making contours of any shape at any angle. The machining centres, equipped with automatic tool changers, are capable of changing 90 or more tools. The usual process flow is: – – – – – – –

Develop or obtain the 3D geometric model of the part, using CAD. Decide which machining operations and cutter-path directions are required (computer assisted). Choose the tooling required (computer assisted). Run CAM software to generate the CNC part program. Verify and edit program. Download the part program to the appropriate machine. Verify the program on the actual machine and edit if necessary .Run the program and produce the part.

The lab also has Electron Discharge machine where an electrical spark is created between an electrode and a workpiece. The spark is visible evidence of the flow of electricity. Intense heat is produced due to this electric spark producing with temperatures reaching from 8000 to 12000 degree Celsius, melting almost anything. The spark is very carefully controlled and localized so that it only affects the surface of the material. The EDM process usually does not affect the heat treat below the surface. The spark always takes place in the dielectric of deionized water. The conductivity of the water is carefully controlled making an excellent environment for the EDM process. The water acts as a coolant and flushes away the eroded metal particles. Also water Jet machining, a non-traditional process, where a jet of water at high velocity and pressure, may be mixed with an abrasive substance like garnet or aluminium oxide, is used to make intricate shapes The process is essentially the same as water erosion found in nature but accelerated and concentrated by orders of magnitude. The most important benefit of the waterjet cutter is its

8 ability to cut material without interfering with the material's inherent structure as there is no "heat affected zone" or HAZ. This allows metals to be cut without harming or changing their intrinsic properties. Machine shop work is generally understood to include all cold-metal work by which an operator, using either power driven equipment or hand tools, removes a portion of the metal and shapes it to some specified form or size. This is the place from where the raw material starts its journey to become the final product. In launch vehicles used by ISRO, Pressurized tanks are used to store air at high pressures so as to maintain the flow rate of the liquid propellants. These tanks, alloy of titanium and vanadium, are manufactured by Brahmos. Initially, two metal plates are made into semi-circular shapes by mandreal and then electron beam welding is done. In an electron beam welder electrons are "boiled off" as current passes through a filament which is in a vacuum enclosure. An electrostatic field, generated by a negatively charged filament and bias cup and a positively charged anode, accelerates the electrons to about 50% to 80% of the speed of light and shapes them into a beam. Due to the physical nature of the electrons - charged particles with an extremely low mass their direction of travel can easily be influenced by electromagnetic fields. Electron beam welders use this characteristic to electromagnetically focus and very precisely deflect the beam at speeds up to 10 kHz. When fast moving electrons hit a metal surface they are decelerated which transforms the kinetic energy of each individual electron in the beam into thermal energy in the component. When electrons in a focused beam hit a metal surface, the high energy density instantly vaporizes the material, generating a so-called key hole. These pressure vessels are then tested in an underground room for a pressure 1.67 times the approximate pressure.

QUALITY CONTROL Quality control (QC) is a procedure or set of procedures intended to ensure that a manufactured product or performed service adheres to a defined set of quality criteria or meets the requirements of the client or customer. Quality Assurance (QA)is defined as a procedure or set of procedures intended to ensure that a product or service under development (before work is complete, as opposed to afterwards) meets specified requirements. QC control and BrahMos: Job Record: Keeps track of the work from its early stage to the following stages including dimensions and tolerances with geometrical changes and processes involved. Very minute details like orientation of the material grains in case of supporting structure components are also included in the job record sheet. After every process the engineer responsible signs at their respective places. Time taken by each process and consecutive measurements are also mentioned very systematically in the job record. Clean room: A clean room is an environment, typically used in manufacturing or scientific research, with a low level of environmental pollutants such as dust, airbornemicrobes, aerosol particles, and chemical vapours. More accurately, a cleanroom has a controlled level of contamination that is specified by the number of particles per cubic meter at a specified particle size. To give perspective, the ambient air outside in a typical urban environment contains 35,000,000 particles per cubic meter in the size range 0.5 μm and larger in diameter. Following are the standards for cleanrooms: Table 1. ISO standards of clean room Maximum concentration limits(paricles/m3) ISO equivalent ≥0.1 ≥0.2 ≥0.3 ≥0.5 ≥5 µm10 µm 2 µm µm µm ISO 1 100 ISO 2 24 10 4 1000 ISO 3 237 102 35 10000 ISO 4 2370 1020 352 100000 23700 10200 ISO 5 3520 29 1000000 237000 102000 35200 ISO 6 293 ISO 7 352000 2930 ISO 8 3520000 29300 The clean room visited had 1lakh particles per m3. Digital 2D height gauge: Used to measure linear lengths and PCD’s with significant accuracy and precision. It has several probes for measurement of different works. Calibration required.

CMM: A coordinate measuring machine (CMM) is used for measuring the physical geometrical characteristics of an object. This machine can be manually controlled by an operator or be computer controlled. Measurements are defined by a probe attached to the third moving axis of this machine. Probes can be mechanical, optical, laser, or white light. A machine which takes readings in six degrees of freedom and displays these readings in mathematical form is known as a CMM. Its advantages include flexibility of measuring dimensions, reduced setup time, improved accuracy, reduced operator dependency and productive. A magnificent bridge type CMM was shining in the QC section with air bearings and a set of probes of all sizes with ruby probes and inductive probes.

SURFACE TREATEMENT The processes of surface treatments tailor the surfaces of engineering materials to     

control friction and wear, improve corrosion resistance, change physical property, e.g., conductivity, resistivity, and reflection, alter dimension, vary appearance, e.g., color and roughness,

Ultimately, the functions and/or service lives of the materials can be improved. Anodising: Anodising is the creation of an oxide layer on the surface of aluminium by electrochemical means. This oxide layer protects the underlying metal and prevents further corrosion from taking place. An additional benefit of this process is that the oxide layer that is created will accept certain dyes, thus allowing aluminium items to be finished in a wide range of colours.

Fig 2 .A schematic of anodising

Dyeing: Typically the dyes used are organic and can be sensitive to acid from the anodizing process or contaminants in the rinse water. Therefore, post-anodizing rinsing is critical before parts go into the dye tanks to avoid contamination of the dye tanks. The pre-dye rinse needs to be a high purity water rinse such as deionized water and room temperature or cooler water. The use of a heated predye rinse would begin to seal the pores in the anodized surface and could reduce the dye pickup into the pores. Depending on the dye, air agitation is either required or forbidden. The dye manufacturer should be able to provide the best practices for their dyes. The dyeing tanks are typically heated per the dye manufacturer’s instructions. The warm dye is drawn into the pores of the anodized layer

12 due to capillary action. Sealing- The sealing operation is the final stage of the anodizing process. Immersion of an anodized part into hot (boiling point) water causes the pores to seal over due to the slight solubility of the aluminium oxide of the anodized surface. This provides stain and corrosion protection for a clear anodized surface and prevents dye migration or degradation in a dyed surface. The hot water used in sealing also needs to be high purity such as deionized water. Sealing additives are also sometimes used such as nickel acetate with boric acid. The use of additives requires additional wastewater treatment. Some of the techniques performed at BrahMos are discussed below: Sulphuric Acid Anodising: Often known as natural, clear or silver anodising, this is the commonest type of anodising, and the description covers a wide range of processes at different levels. The process differs from hard anodising in that the electrolyte temperature is higher and the current density employed is lower. The types of sulphuric acid are sub-divided into classes mainly determined by the field of application. All anodising processes are sealed unless the film is used as a primer for paint or adhesives. Chromic Acid Anodising: Compared with sulphuric acid anodising, it gives relatively soft, thin coatings, normally of two to five microns thickness. These are used mainly for electrical insulation and general protection against corrosion under mild conditions. Unsealed coatings are used as a 'key' for paints and adhesives. It is light grey in colour, with a very silky texture. Chromic acid anodising is particularly useful when:      

It is necessary to minimise the loss of fatigue strength of workpiece, as compared with sulphuric acid-type processes. The item to be anodised contains crevices or small blind holes from which it may be difficult to remove electrolyte. The coating is on metal less than 250 microns thick, the process and resultant coating have less adverse effect upon the properties of the underlying metal. Components containing crevices or small blind holes. Pre-treatment for painting, especially in aerospace applications. Flaw detection - technique for identifying cracks, folds, inter-crystalline corrosion, machining damage, incipient melting of grain boundaries, cold shuts, etc.

In the surface treatment in BrahMos, the layer of chromic gas was less than 10 micron thick as compared to Sulphuric gas which was nearly 20 micron thick. The temperature of working for

13 chromic anodising was 400C and 150C for sulphuric anodising. The systematic steps for the anodising include Vapour Degreaser  Alkaline SoakCaustic EtchingChromic Acid AnodisingHard Chromium PlatingDe-smutting (with citric acid) Dyeing The dying was done using organic agents by impregnation process. Chemical Milling: The chemical milling process utilizes chemicals rather than cutting tools to etch shapes in metal. Depending on the design of the part and desired volume of parts necessary, chemical milling can be an economical machining option, and it is regularly employed for a wide number of applications. Tooling for chemical milling is relatively simple, as it is generated using CAD software, with little to no need for replacement parts. Additionally, the process does not alter the structure of the remaining metal, which occurs in a variety of other physical machining processes. However, the process is only suitable for metals of relatively limited thicknesses, except in situations where only etching is required. At BrahMos chemical milling was used to contour a complex skin panel section. Several layers of material were removed to make slots and geometries. The process of chemical milling begins with a CAD file, which is sent to or produced by the fabrication service (according to customer specifications). Once received, the fabricator creates a graphic representation of the file, which will map the pattern on the top and bottom surface of the metal to be milled, and selects the type of metal to undergo the process. Before any other steps can be performed, the metal must be thoroughly prepared and cleaned for the application of photo-resist material. After the metal is cleaned, the photo-resist material is applied to both sides, then developed using UV light and chemicals. The remaining photo-resist material maps the areas that will be removed by the application of acid, which is then sprayed on the coated part. After the acid has been given sufficient time to work, the component is removed from the chemical milling area and the layer of photo-resist material is removed.

APPENDIX Table 2. List of students in the visit SR. NO. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19

NAME OF THE STUDENT AKHIL JAISWAL AMAL JYOTHIS AMAN GUPTA AMIT KAMBOJ DIVESH SONI GAURAV VAIBHAV J. YUDHISHTR MANIMARAN SAMAR MANISH KUMAR MISHRA MARIYA RATLAMI MAYANK KUMAR MOFEEZ ALAM MOHD. AHMAD RAHUL TANWAR RAJEEV VARMA RAMAN CHAWLA SREEAJ VARMA SWAPNIL KUMAR TANMAY SINGHAL

Table 3. List of Contacts in BATL SR no 1

CONTACT PERSON Shri. Rajeev Madhavan Manager BATL

Shri. Sunil Kumar Deputy GR BATL

Table. 4 List of faculty members for visit SR no 1 2 3 4 5

Faculty name Dr. Praveen Krishna Dr. Pradeep Kumar P Dr. Deepu M. Dr. Satheesh K Dr. B.R. Vinoth