Inside-out: Statistical methods for Computed Tomography validation of complex structures in Additive Layer Manufacturing

Additive layer Manufacturing (ALM) is a "3D printing" technique which develops products directly from their digital design data by the layer-wise addition of material. It is widely regarded as having great promise, especially for its capabilities to respond cost-effectively to changing customer demand and its ability to create objects with complex internal structure. At present a major difficulty holding back ALM is the problem of determining the extent to which the digital design has been correctly realized by the process: direct verification typically involves lengthy analysis of individual manufactured objects using Computed Tomography (CT) scans, tending to vitiate the advantages of ALM for general purposes. The purpose of this project is to explore methods by which this quality assurance process may be carried out more rapidly. The investigation will be carried out by a close collaboration between engineers and statisticians at Warwick using statistical techniques including random fields, false discovery rate methods, and ideas from stochastic geometry.

Who Will Benefit from the Research
With its focus on enabling the rapid and accurate quality assessment of complex Additive Layer Manufactured (ALM) components, and increasing their acceptance in the High Value Manufacturing (HMV) sectors, the beneficiaries will be the UK HMV industry, providers of ALM and Computed Tomography (CT) technologies, the UK government and society (e.g. consumers of energy, users of air transport, healthcare users) and the environment.

How Will They Benefit from the Research
Economic Impact: The UK has a healthy High Value Manufacturing sector, and a particularly strong aerospace manufacturing presence. UK aero engine manufacturing is 2nd in the World, with key players, including BAE Systems, Bombardier, EADS, and Rolls-Royce, worth £23.5bn in 2011-12, and predicted to reach £26.2bn in 2016-17. The UK's biomedical sector, and especially the orthopaedic and implantables market is worth over £400m (UK) and over £10bn globally, and is expanding at a Compound Annual Growth Rate (CAGR) of over 7%, with key players such as S&N, Zimmer, Stryker, Biomet. Both sectors will benefit from the ability to cost-effectively deliver new products with enhanced customer benefit (advanced fuel injectors and combustion systems with improved fuel performance, customised biomedical implants for improved fit and longevity). Increased uptake in these and other sectors will benefit ALM and CT Original Equipment Manufacturers (OEMs) through increased revenues. It has been estimated that, by overcoming the current limitations of ALM and gaining market acceptance, penetration could be expected to expand from 8% to 92% by 2020, a market worth £66bn globally [1].

Social and Environmental Impact: This research will enhance the capability of ALM technologies, which are inherently resource efficient, encouraging their use in HVM and thus displacing more traditional resource intensive and inefficient manufacturing processes. This is thus in alignment with the global strategies (e.g. Kyoto Treaty) to reduce environmentally damaging emissions through our increasing use of resources. The research supports the development of leaner, fuel efficient turbofan aero engines and gas turbines for energy generation. This will contribute toward the reduction of the negative environmental impact of air travel and energy generation, and will facilitate the continued globalisation of society, and the economic and social benefits that that brings, without detriment to the environment. The UK government will benefit in being aided in attaining its targets on climate change, and through economic savings in hospital care achieved through better provision of orthopaedic treatment (better outcome, faster recovery times, less trauma, fewer revisions and complications) made possible by customised orthopaedic implants. When full market penetration is reached, the savings to the healthcare sector within Europe are estimated to exceed £2.5bn annually. Social benefits will be in a greener environment, sustainable globalisation, and a higher quality of life and health.

1. Wohler, T. Wohlers Report 2012 - Additive Manufacturing and 3D Printing State of the Industry. 2012