3D printing with metals: An exciting opportunity for the manufacturing industry

2017 edition

Eric Neiva

Additive Manufacturing (AM) or 3D printing refers to a group of manufacturing technologies that build three-dimensional objects layer by layer from a computer-aided design model. AM methods are able to create objects with shapes and properties that cannot be easily produced with conventional manufacturing processes. For this reason, it is expected to play a key role in future technological revolutions.

In fact, AM methods have been used for about thirty years for rapid prototyping of products and they have already proven potential benefit for a wide variety of industrial sectors, including the aerospace, automotive, orthopaedic, dental, robotics or consumer goods. Successive technological advances allow now to apply these technologies in mass production of plastic or metal components.

Most metal AM systems use high power lasers to build parts layer upon layer by melting metal wires or fine metal powders. Currently, it is possible to 3D-print a wide variety of metal parts in aluminum, high-grade steel, and titanium, as well as nickel and cobalt alloys. In spite of this, there is still a long way to a wider adoption of metal AM in the industry.

Among the reasons for this is the difficulty of specifying the printer settings for a given metal part. The printing process depends on many parameters and not all of them are suitable to produce the part such that it meets the geometric requirements. However, the most serious hurdle is the uncertain quality of the final product. Even if the shape is correct, the internal structure of the part may not satisfy the performance requirements.

Current practice in the industry to fulfill the previous requirements consists of an expensive and time-consuming trial-and-error experimental campaign. The product is reproduced and tested hundreds of times until it reaches its final status. This traditional qualification approach makes it difficult for producers to later exploit the speed, flexibility, and cost savings that AM offers.

As a result, there is an increasing demand of a software ecosystem that enables computer-aided technologies to support metal AM processes and machines. Computer-aided simulations could allow engineers to virtually predict the quality and performance of a product, without experimental-based testing, leading to faster and cheaper product design with metal AM.

My research activities aim to contribute to the virtualization of design and qualification in AM with metal powders. In particular, the goal is to enable the virtual design of the printing process with efficiently parallel finite-element thermomechanical analysis tools. This is being carried out by joining the experience of two research groups in CIMNE-UPC: the group leading the numerical simulation of metal forming processes within the Structural Mechanics department and the Large Scale Scientific Computing department.