11th January 2018

What is additive manufacturing and how is it relevant to aerospace industry?

- By Dassault Systèmes

This year in Medanta, Gurgaon, surgeons replaced the first, second and third vertebrae of a 32-year-old teacher with exactly matched 3D printed parts. This life-saving operation was the first of its kind in India. Because no two humans vertebrae are the same, one size does not fit all, and implanting a replacement that is only slightly incorrect could do more harm than good. “Given the complexity of this case, the use of 3D printing technology has helped us in bringing a successful outcome,” Dr. V Anand Naik, senior consultant (spine surgery) at Medanta’s Bone & Joint Institute, who lead the surgical team, told the Indo-Asian News Service.

At its genesis, some 30 years ago, 3D printing was restricted to plastic. The advent of laser sintering metal powder changed the game because it allows metal objects to be printed. Almost every type of metal can be used by putting down successive layers of metal powder that is then solidified using precisely targeted heat from lasers.

Additive manufacturing (AM) goes beyond 3D printing. It has evolved into a production and manufacturing technology that displaces or complements conventional processes in an increasing number of applications across the whole industrial spectrum. Additive manufacturing allows a 3D digital model to be perfectly reproduced as a solid object. Additive Manufacturing has the ability to build parts on demand with designs that include internal cavities and lattices – known as bionic structures, that reduce weight and maximize strength without compromising mechanical performance. This is very attractive to the aerospace industry where weight reduction is of significant benefit because it leads to better fuel consumption, longer range, reduced carbon footprint and more innovative design possibilities. Even complex mechanical parts – an encased set of gears, for example – can be made without assembly.

Using integrated design and analysis software on a unified platform enables ‘hard points’ i.e. points of contact, to be defined as design drivers. This means that points of contact, space envelopes and functional and structural requirements can be used to define forms automatically in a process called Generative Design. Integrating finite element (FE) analysis into the design process in real-time makes it possible to validate products for structural characteristics under different operating scenarios. Designing this way not only saves time but also helps overcome India’s current skills shortage for highly qualified design engineers because part of the design process is automatic.

Innovative enterprises that deploy AM are springing up across India in areas as diverse as medical and dental implants, footwear, the automotive and aerospace industries, industrial machine and legacy parts, building, and jewellery. With its low start-up costs and capital requirements, investors are attracted to AM while designers and engineers find the technology liberating because it frees them from traditional manufacturing constraints. And because parts do not have to conform to the structures of machining and finishing they can take on new forms.

Predictability of form, performance, and lifespan are built into AM because digital designs are exactly reproduced as solid objects, and the digital model has all the characteristics of its physical counterpart. Residual stress, thermal, evaluation and cooling rates can also be calculated and virtually validated prior to part manufacture. Another benefit is that there is no wasted as happens with subtractive machining where shapes are cut from solid material blocks of often valuable metals such as titanium. And Additive Manufacturing uses 90% less energy than traditional machine tools.

Additive Manufacturing is used extensively by aerospace OEM partners including Airbus Group which after a two-year comprehensive benchmarking process, is extending its use of additive manufacturing by integrating design, simulation, and production. Additive manufacturing is creating exciting new opportunities in many different areas such as remote fabrication for support and maintenance, rapid prototyping for realizing new concepts and experiences and, perhaps most importantly, developing designs that were previously impossible to fabricate using standard machine tools. Deploying Additive Manufacturing brings otherwise dispersed islands of expertise onto a single unified platform. This provides the ability to access all relevant data from one source, meaning there is only one version of the truth. Digitally simulated parts can also be placed in real-life contexts to show how they will behave and perform when made. And 3D simulations can also include time, to demonstrate product performance over its lifecycle.

3D printing and AM present new opportunities to many of our national manufacturing sectors. When run on a cloud hosted seamless and unified platform that builds bridges between skills, the advantages, and benefits of these exciting technologies are multiplied. This dynamic evolution is attracting interest and bright minds because Additive Manufacturing is at the cutting edge of Indian industrial progress. Like all good technology, it makes complexity simple and for some – it’s a life saver.