3D Printing in Aerospace Industry

Introduction  Additive manufacturing or 3D printing is the process of creating 3D objects or products layer by layer using a 3D digital model. 3D printing is the reverse of traditional manufacturing process such as machining, in which one starts with a block of material and then chips away the unwanted material. 3D printing can also start with a blank platform where material is added in a controlled method where required – in each layer – until the final part is produced. The 3D model can be created using a 3D CAD software right from the scratch or through reverse engineering using laser scanning.  3D Printing in Aerospace Industry  While 3D printing seems to have found some role in almost every industry, it stands out in aerospace. It is one of the pioneering industries where additive manufacturing is firmly entrenched. As per one survey, the market for 3D printing hardware in aerospace engineering will exceed Rs. 110 billion by the year 2019. This is only the hardware; 3D printing raw material is predicted to reach about Rs. 100 billion in the same period. Stalwarts like GE have already adopted 3D printing in a big way for aerospace engineering, so much so that it acquired two leading manufacturers of metal powder bed fusion technologies. Since GE is one of the companies that have conducted the most extensive studies on the cost-effectiveness of 3D printing for aerospace production, it looks safe to assume that this is one sector which merits attention.  Benefits of 3D Printing for the Aerospace Industry  Aerospace industry is one of the few industries where weight of components really matters. The industry is always on the lookout of components that are stronger, lighter and durable. 3D printing technology of today has created new possibilities to meet these challenges. By removing constraints related to traditional manufacturing processes – which are essentially time consuming and limited by the choice of raw material – additive manufacturing has brought forth the potential for numerous design related improvements in aircraft. For commercial airliners, even a minor reduction in weight can make a significantly positive cost impact. For defence planes and spacecrafts, sturdier and lighter components allow better payload. And of course, for all kinds of aircrafts, the lighter the components, better the speed and higher the fuel efficiency.  i. Weight Reduction  Let us talk figures. An airliner in the A330 class typically consumes about 0.035 l/seat/km with 261 seats and a take-off weight of 233 tonnes. Let us guess that the average gross weight is about 200 tonnes, and that the aircraft flies for 25 years, 250 days/year and a range of 200 - 800 km/day. Thus, the total flown kilometers in the life of the plane are estimated to be 100 million km.  With the above fuel consumption and passenger utilization, the total life fuel consumption yields one billion liters of jet fuel or about 5000 liter per kilogram flight mass.
[source: https://www.diva-portal.org/smash/get/diva2:13224/FULLTEXT01.pdf]A saving of as low as Rs. 1 / km will result in a saving of Rs. 1 billion for the airliner over its lifetime. As you can see, even a small decrease in the weight of the airliner saves a huge of money over its lifetime. An added bonus is that lesser consumption of fuel means that much less environmental pollution.  Another example is that of Boeing. A Boeing 747 burns around 4.3 l of fuel each second, or about 155 kl of over the course of a 10-hour flight. If the weight of the aircraft is reduced even by a few kilos, it makes a significant reduction in the fuel consumption, adding to the airliner’s bottom line.  The next level of weight reduction in aerospace industry will be fuelled by a number of new technologies and new materials within the 3D printing field. Metal powder-bed based additive manufacturing systems can offer substantial weight reductions to titanium parts, which make up around 15% of a plane’s total weight. A new generation of composite materials has now been engineered for 3D printing, both by extrusion and plastic powder bed fusion technologies, which possess mechanical properties comparable or superior to milled aluminium. Weight benefits are also started to be quantified in more cost efficient manufacturing as well, thanks in part to steep growth in adoption of metal powder bed technologies with very high deposition rates and hybrid CNC capabilities.  ii. Improved Aircraft Design  Another benefit 3D printing offers aerospace industry is improvement in the aircraft design. As the software for 3D printing increases in sophistication, it is enabling engineers to optimize designs that specifically benefit from additive manufacturing processes. These improvements will reduce the life-cycle cost of the plane by increasing engine efficiency, reducing drag and decreasing the mass of the aircraft.  iii. Improved Supply Chain  Developing and producing an aircraft is a huge job. Aircraft demand is characterized by long lead times, production schedules and production backlogs that may last years. As 3D printing allows production of varied components using a broad spectrum of raw material, it increases the production efficiency and improves the supply chain lead times.  3D Printing Material  The aviation and aerospace industry has unique demands about the 3D material that is used. It has to be sturdy yet light and resilient yet strong. 3D printing is now used to manufacture almost all aircraft parts like engine, nozzles, cabin accessories, air ducts, engine suspension, dashboard bezels, brackets, etc. typical 3D printing for the aerospace industry includes nylon, resins of various sort, light weight metals like titanium and aluminium, digital ABS, etc. in particular, Stratasys, industry leader in the 3D printing sector, has introduced a thermoplastic filament called ULTEM™ 9085 Resin. This resin material from Stratasys features a high strength-to-weight ratio, high thermal and chemical resistance, and meets multiple aerospace industry standards for flame, smoke and toxicity characteristics. This Stratasys 3D printing material is ideal for aviation and aerospace applications.  3D Printing and Aerospace Industry in India  India is adopting 3D printing technology gradually. The Indian aviation industry is poised to grow at an astounding rate. It will be the second or third largest in the world in a year or so. Among foreign manufacturers, Airbus, Lockheed and Boeing have a presence in India. These companies already use 3D printing. Hindustan Aeronautics (HAL), which is the sole military aircraft producer in India, has taken positive steps in embracing 3D printing technology. The company has used 3D printing technology to create a prototype model for a 25-kN aircraft engine, which was displayed at Aero India Expo (2015). Another Bengaluru, India based company produced various aircraft engine prototype components from nylon plastic material using Selective Laser Sintering additive manufacturing process. What is more, they produced these components in less than 20 days. Indian manufacturers are now recognizing that 3D printing drastically reduces prototype development time and cost compared to conventional manufacturing. As India looks to be self reliant in the aerospace sector, the future of 3D printing looks bright.