RMIT Centre for Additive Manufacturing

Finding the most effective etchant for additively manufactured Ti-alloys is always challenging!   Kroll’s reagent is effective for the metallographic etching of traditional #Ti-alloys but struggles with the intricate, refined microstructures of newer Ti-alloy compositions like #Ti-Cu and Ti-Mo alloys, which are created through additive manufacturing.   Researchers at the RMIT Centre for Additive Manufacturing have systematically investigated the use of buffered oxide etch, a common etchant for microelectronics, on a range of additively manufactured Ti-alloys. The results show that buffered oxide etch provides superior etching outcomes compared to Kroll’s reagent and ammonium bifluoride, with a clear colour contrast between grains and fine phases.   The article titled” Buffered Oxide Etch: A Safer, More Effective Etchant for Additively Manufactured Ti‑Alloys” is now available in the journal 𝐌𝐞𝐭𝐚𝐥𝐥𝐨𝐠𝐫𝐚𝐩𝐡𝐲, 𝐌𝐢𝐜𝐫𝐨𝐬𝐭𝐫𝐮𝐜𝐭𝐮𝐫𝐞, 𝐚𝐧𝐝 𝐀𝐧𝐚𝐥𝐲𝐬𝐢𝐬. Congratulations to all authors, Jayshri Dumbre, Zherui Tong, Dashen Dong, Dong Qiu and Mark Easton on their fantastic work. 👏 🌺   Find more about the paper here: https://lnkd.in/gQGE9Wjd #additivemanufacturing #3dprinting #RCAM

The article “Systematic Investigation of Performance and Productivity in Laser Powder Bed Fusion of Ti6Al4V up to 300 µm Layer Thickness” is now available in the Journal of 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐏𝐫𝐨𝐜𝐞𝐬𝐬𝐢𝐧𝐠 𝐓𝐞𝐜𝐡𝐧𝐨𝐥𝐨𝐠𝐲 (open access link: https://lnkd.in/gf_sfcUH). In this paper, the authors examine how an increase in layer thickness affects microstructure, mechanical properties, relative density, and overall productivity of Ti6Al4V components manufactured by laser powder bed fusion. In contrast to the conventional range of layer thickness, typically from 20 µm to 60 µm, this study systematically investigates process-property-relationships for powder layers between 60 µm and 300 µm thickness. The findings underline the effectivity of increased layer thickness to improve productivity in laser powder bed fusion while maintaining high levels of relative density and strength. The research pushes the boundaries of processability and productivity for laser powder bed fusion, enabling more rapid fabrication of high-quality Ti6Al4V components for applications in the medical, defence, and aerospace sectors. Congratulations to all the authors Simon Brudler, Alexander Medvedev, C. Pandelidi, S. Piegert, T. Illston, Ma Qian and Milan Brandt on their wonderful work. 👏 🌺 #additivemanufacturing #3dprinting #RCAM #powderbedfusion #rmituniversity

We are delighted to announce a new publication from our centre! The article titled 'A strong and ductile biocompatible Ti40Zr25Nb25Ta5Mo5 high entropy alloy' in the Journal of 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐑𝐞𝐬𝐞𝐚𝐫𝐜𝐡 𝐚𝐧𝐝 𝐓𝐞𝐜𝐡𝐧𝐨𝐥𝐨𝐠𝐲. The authors have developed a non-equiatomic Ti40Zr25Nb25Ta5Mo5 high entropy alloy (HEA) from the precursor Ti40Nb25Zr25Ta10 HEA by substituting 5 at.% Ta with 5 at.% Mo, aiming to enhance mechanical properties and reduce density. The Ti40Nb25Zr25Ta5Mo5 HEA was fabricated using copper mold casting, resulting in an approximately equiaxed grain structure with an average grain size of 96 ± 16 μm. Backscattered electron imaging revealed dendritic structures within the equiaxed grains, with dendrites enriched in Ta, Nb, and Mo, and inter-dendritic regions containing higher concentrations of Zr and Ti. Read more about the paper here:https://lnkd.in/g7DJ_bjb Congratulations to all authors, Dr. Labani Mustafi, V.T. Nguyen, Dr. Tingting Song, Q. Deng, B.J. Murdoch, X.-B. Chen, Daniel Fabijanic, and Prof. Ma Qian, on their latest publication." 🌺 👏 #additivemanufacturing #3dprinting #RCAM #rmituniversity #research

Congratulations to Dr Mahyar Khorasani on being awarded “The Vice-Chancellor’s Award for Research Engagement and Impact”. 👏 This award recognises his research and active engagement in the realm of 3D printing techniques for manufacturing components in the transportation sector. Mahyar has recently returned from the USA, where he completed a Fulbright Scholarship as a Post-Doctoral Academic Fellow at the University of El Paso in Texas. He is currently a senior lecturer at the RMIT STEM College and has also been awarded an Industry Fellowship by the Australian Research Council (#ARC), supported by Ford Motor Company. Currently, he is a leading researcher in a collaborative project between Ford Motor Company and RMIT University, aiming to develop pioneering simulation techniques for #multi-jet fusion-based #additive manufacturing (#AM). We wish him all the best in his research and look forward to the results. 🌺 #additivemanufacturing #3dprinting #award #RCAM #rmituniversity

Cracking is a significant issue in 𝐋𝐚𝐬𝐞𝐫 𝐀𝐝𝐝𝐢𝐭𝐢𝐯𝐞 𝐌𝐚𝐧𝐮𝐟𝐚𝐜𝐭𝐮𝐫𝐢𝐧𝐠 for numerous high-strength aluminium alloys, such as AA6061. Researchers at the RMIT Centre for Additive Manufacturing, in collaboration with Technische Universität Ilmenau in Germany and the ESRF - The European Synchrotron Radiation Facility in France have conducted a novel study using a pulsed laser with ramp-down power modulation to improve the cracking resistance by about 50% compared to the use of a rectangular pulsed laser. They implemented synchrotron in situ X-ray imaging at 100,000 images per second, obtaining ground truth data about changes in melt pool geometry, solidification rate, and thermal gradients. The article titled "In situ observation and reduction of hot-cracks in laser additive manufacturing" is out now in the Journal of 𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐜𝐚𝐭𝐢𝐨𝐧𝐬 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬. Congratulations to all authors, Yunhui Chen, Duyao Zhang, Patrick O'Toole, Dong Qiu, Marc Seibold, Klaus. Schricker, Jean-Pierre Bergmann, Alexander Rack and Prof. Mark Easton on their wonderful publication. 👏 🌷 Find the paper here: https://lnkd.in/gxxkygsa #additivemanufacturing #3dprinting #RCAM #collabration #research #LB_PBF #rmituniversity

We’re happy to share our latest publication from the centre. The article titled “Enhancing the Crystallization Kinetics and Mechanical Properties of Poly(lactic acid) Blends for 3D Printing Application” is now out in the journal ACS Applied Energy Materials. The authors investigated the synthesis of a low molecular weight PLA−PEG−PLA triblock copolymer, and its blending with PLA has proven to be a successful strategy for enhancing the properties of 3D-printed PLA. The incorporation of PLA−PEG−PLA resulted in improved miscibility with PLA. Blending 15 wt% of this copolymer into PLA increased the elongation at break by 45-fold (from 2.2% for PLA to 94.1% for mPLA15) and enhanced the tensile toughness by 23-fold (from 7.7 kJ/m³ for PLA to 176.7 kJ/m³). PLA−PEG−PLA led to a significant increase in the crystallization rate and overall crystallinity of the blend. Nucleation efficiency calculations helped elucidate the pivotal role played by the PEG middle block in augmenting both the overall crystallinity and the rate of crystallization in the mPLA blends. The improved mechanical properties, crystallinity, and crystallization rate make this blended material a promising candidate for advanced 3D printing applications, emphasizing the significance of the PLA−PEG−PLA triblock copolymer in enhancing the overall performance of PLA-based 3D-printed materials. Congratulations to all authors Premkumar Kothavade, Prashant Yada, Animesh Gopal, Harshawardhan Pol, Abdullah Kafi, Stuart Bateman, and Kadhiravan Shanmuganathan on their latest publication. 🌺 Find more here: https://lnkd.in/gFAAQqfH #additivemanufacturing #3dprinting #RCAM #rmituniversity #research

Another exciting publication from the RMIT Centre for Additive Manufacturing! The article titled” Finite element analysis of patient-specific additive-manufactured implants” is out now in the Journal of Frontiers in Bioengineering and Biotechnology. The authors delve into the comprehensive assessment of patient-specific additive-manufactured implants in femur bones from an animal trial using finite element modelling. This work investigates the mechanical behaviour of these implants after bone tumour resection, examining how varying implant structures impact bone behaviour under compression and torsion loading. The findings underscore the remarkable potential of lattice implants in revolutionising orthopaedic care. By promoting bone ingrowth and reducing implant stiffness, lattice implants offer a promising solution to combat significant bone remodelling often associated with traditional solid implants and the phenomenon of stress shielding. The research has profound implications for clinical practice and the insights gained from our study pave the way for optimising implant design in complex orthopaedic scenarios, ultimately leading to improved patient outcomes and enhanced quality of life. Congrats to all authors, Arman Namvar, Bill Lozanovski, David Downing, Tom Williamson, Endri Kastrati, Darpan Shidid, David Hill, Ulrich Buehner, Stewart Ryan,  Peter F. Choong, Reza Sanaei, Prof. Martin Leary and Prof. Milan Brandt on their fantastic publication. 👏 🌺 Read more here: https://lnkd.in/ghGBYpaU #additivemanufacturing #3dprinting #RCAM #rmituniversity #research

We’re excited to share the latest publication from our researchers at the RMIT Centre for Additive Manufacturing. The paper “𝐓𝐡𝐞 𝐈𝐦𝐩𝐚𝐜𝐭 𝐨𝐟 𝐒𝐮𝐫𝐟𝐚𝐜𝐞 𝐎𝐫𝐢𝐞𝐧𝐭𝐚𝐭𝐢𝐨𝐧 𝐨𝐧 𝐒𝐮𝐫𝐟𝐚𝐜𝐞 𝐑𝐨𝐮𝐠𝐡𝐧𝐞𝐬𝐬 𝐚𝐧𝐝 𝐅𝐚𝐭𝐢𝐠𝐮𝐞 𝐋𝐢𝐟𝐞 𝐨𝐟 𝐋𝐚𝐬𝐞𝐫-𝐁𝐚𝐬𝐞𝐝 𝐏𝐨𝐰𝐝𝐞𝐫 𝐁𝐞𝐝 𝐅𝐮𝐬𝐢𝐨𝐧 𝐓𝐢-𝟔𝐀𝐥-𝟒𝐕” is now available in the journal ‘𝐀𝐝𝐝𝐢𝐭𝐢𝐯𝐞 𝐌𝐚𝐧𝐮𝐟𝐚𝐜𝐭𝐮𝐫𝐢𝐧𝐠’ (open-access link below). Link here: https://lnkd.in/g4AVhtU9 This research demonstrates that by removing downward-facing surface roughness alone, fatigue life can increase by up to 50% at low loads; a significant finding for fatigue-limited components with inaccessible surfaces. Congratulations to the authors Jason Rogers, Dr. Joe Elambasseril, Chris Wallbrink (Defence Science and Technology Group (DSTG), Beau Krieg (Defence Science and Technology Group (DSTG), Prof. Ma Qian, Prof. Milan Brandt, and Prof. Martin Leary on this significant contribution. 👏 🌺 This project was funded by the Defence Science and Technology Group (DSTG). #additivemanufacturing #3dprinting #Fatigue #RCAM #rmituniversity #DSTG

Congrats to Anirban Changdar, ShitanshuShekhar Chakraborty, Yuncang Li, and Cuie Wen on their latest paper just published in the Journal of 𝐌𝐚𝐭𝐞𝐫𝐢𝐚𝐥𝐬 𝐒𝐜𝐢𝐞𝐧𝐜𝐞 & 𝐓𝐞𝐜𝐡𝐧𝐨𝐥𝐨𝐠𝐲. 🌺 👏 The authors of this article reviewed the potential of laser additive manufacturing (AM) techniques in producing aluminum-based cellular materials. The paper discusses the distinctions between stochastic foams and nonstochastic lattice structures and how laser powder bed fusion (#LPBF) and directed energy deposition (#DED) have revolutionized their production. It identifies the limitations of traditional manufacturing methods while highlighting the advantages of #AM, including design flexibility, shorter lead times, and the ability to create complex geometries. The paper highlights various #LAM technologies, including laser powder bed fusion (#LPBF) and directed energy deposition (#DED). Techniques like selective laser sintering (#SLS), selective laser melting (#SLM), and direct metal laser sintering (#DMLS) have been instrumental in fabricating high-accuracy, complex cellular structures. A comprehensive review “Laser additive manufacturing of aluminum-based stochastic and nonstochastic cellular materials” is out now. Read more here:https://lnkd.in/gUxyVwH5 #additivemanufacturing #3dprinting #RCAM #research #laserbasedpowderbedfusion #rmituniversity

We are pleased to share another fantastic publication from our researcher at the RMIT Centre for Additive Manufacturing.   The article, titled "Optimizing the Manufacturing of a β-Ti Alloy Produced via Direct Energy Deposition Using Small Dataset Machine Learning," is now available in the Journal of 𝐒𝐜𝐢𝐞𝐧𝐭𝐢𝐟𝐢𝐜 𝐑𝐞𝐩𝐨𝐫𝐭𝐬.   In this recent publication, the authors have coupled machine learning techniques with a prescriptive design of experiments to efficiently map a process space for the direct energy deposition of a Ti-Fe alloy. With variations in laser power, speed, and spot size, we were able to accurately model the resulting layer height and grain size. Our artificial neural network model for grain size accurately predicted the layer height setting, reducing setup time for materials. The grain size modeling demonstrated the level of control over the final microstructure by the process parameters. Through variations in process parameters, we were able to reduce the average grain size from 133μm to 38μm. They successfully replicated this grain refinement in another α+β Ti alloy, highlighting the application of this finding.   Congratulations to all authors, Ryan Brooke, Dong Qiu, Tu Le, Mark A. Gibson, Duyao Zhang, and Prof. Mark Easton, on their wonderful work. 🌺 👏 Read more: https://lnkd.in/gMip3fkg #additivemanufacturing #3dprinting #RCAM #rmituniversity #research