Cambridge Techworks Ltd


Renishaw plc


ILAS 2019: ACADEMIA-INDUSTRY COLLABORATION


optically-smooth craters, a few microns wide and a fraction of a micron deep, with a high degree of dimensional control. Tese craters have been used as the basis of holographic structures, by creating a suitably patterned array of craters on a smooth metal surface (see Figure 2). When illuminated with a visible laser beam, light reflected from these craters interferes with that reflected from the unprocessed metal surface, creating a diffractive image that can be viewed on some kind of screen, e.g. a piece of paper or card, placed a short distance away. Tis work is now being translated to industry via further support from an EPSRC Impact Acceleration Account. A patent was filed in 2017 on techniques to hide additional information in the holograms, and we are now working with Sisma, in Italy, to incorporate the process into their laser marking machines for applications in the jewellery industry.


Holographic diagnostics of laser-based processes Laser manufacturing processes have, in general, been developed empirically, that is, based on observation and experience, rather than derived from theory. Whilst this approach has been very successful, the large number of variables involved means that large regions of potential parameter space remain unexplored, and many processes are likely not optimised. To address this, in CIM-


Laser a gigahertz frame rate holographic camera has been developed to provide a proper link to process and material fundamentals. Tis has now been commercialised by Cambridge Techworks (see Figure 3), with a ready market in laser processing research laboratories.


Figure 4: a project at CIM-Laser contributed to the development of Renishaw’s quad laser AM machine


years we have delivered a significant volume of industry-focused manufacturing research, much of which is now being transferred to industry


During the past five


Wire and laser additive manufacturing (WLAM) A fundamental study of this process was made within CIM-Laser, including a study of the critical parameters underpinning the process, resulting


in development of a well-controlled deposition system, and demonstration of high build rate and net shape deposition. Tis led to additional major EPSRC and industry funding – £8.7 million – for the NEWAM Programme Grant, led by Cranfield University, to transform large-area metal additive manufacturing, by pioneering new high build-rate wire-based processes with greater precision of shape and microstructure. A key focus is to guarantee as-built structural integrity with


process-independent physics-based quality control and assurance, enabling low-cost industrial qualification.


Figure 3: Falcon gigahertz frame rate holographic camera www.lasersystemseurope.com | @lasersystemsmag


Multi-laser powder bed fusion Powder bed additive manufacturing has enjoyed great commercial success in recent years, however it remains slow, with builds taking many hours or days to complete. Te process is also plagued by problems with residual stress, which can warp parts, lead to catastrophic failure during manufacture and premature fatigue failure during operation. In CIM-Laser we have developed equipment and processes to measure the effectiveness of a multi-laser powder bed process, and instigated the development of new high- throughput melting strategies that also minimise residual stress. Tis has contributed to the


development of a new AM platform by Renishaw (see Figure 4). Te University of Liverpool is continuing to work closely with Renishaw to ensure that developments are transferred rapidly into products.


Refractory material for laser powder bed fusion Refractory metals such as tungsten and niobium are extraordinarily resistant to wear and high temperature, so they are important high-value materials. However, their high temperature properties


mean that they are very difficult to process using AM. By carrying out detailed process development supported by fundamental knowledge, we have defined suitable parameters with which these materials can be processed effectively. We have designed and modified production equipment to enable use of these parameters, and have identified stable processing regimes to facilitate this effective production. A further two-year project has been secured to


transfer the developed process knowledge to a commercial platform – Renishaw’s RenAM 500M – and the industrial partners have reported that they are adapting the technology to replace conventional and expensive manufacturing routes.


Professor Hand is the director of CIM-Laser and deputy head of the School of Engineering and Physical Sciences at Heriot-Watt University in Edinburgh, Scotland.


ISSUE 42 • SPRING 2019 LASER SYSTEMS EUROPE 19


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36