Session Chair: Jun Ding, National University of Singapore Session Chair: Pan Wang, Singapore Institute of Manufacturing Technology, Agency for Science, Technology and Research (A*STAR)
1:30pm - 2:00pm Invited
Leading SC3DP Additive Manufacturing Research Initiatives in Singapore
Kah Fai LEONG, Chee Kai CHUA
Nanyang Technological University, Singapore
In recent years, Additive Manufacturing (AM), or commonly known as 3D Printing, has radically changed the way that many industries design and develop new products. In the aerospace industries, AM has been used to design and create complex and efficient fuel injection nozzles in aircraft engines, in the medical areas, it is used to fabricate scaffolds for tissue engineering and even organ regeneration; and in the automotive industries, it produces more complex and sophisticated components for power delivery systems. It is therefore not surprising that this technology has stirred substantial interests in the manufacturing industries in Singapore. AM has opened up new pathways towards more innovations and revolutionize the relationship between the manufacturing and products realization that can be applied to many sectors. The Singapore Centre for 3D Printing leads AM research in Singapore in several of these areas, particularly in the Future of Manufacturing, Aerospace and Defence, Building and Construction, Marine and Offshore, and Biomedical Engineering Sectors.
2:00pm - 2:30pm Invited
Laser Additive Manufacturing of Super Metals Containing Self-dispersed Nanoparticles
University of California Los Angeles, United States
Recent breakthrough on nanoparticle self-dispersion and stabilization in molten metals paves a new, exciting way to produce bulk super metals containing uniformly-dispersed nanoparticles for super high performance. Novel super metal micro powders containing uniformly-dispersed nanoparticles can be a powerful feedstock material for additive manufacturing of complex metal parts with unusual mechanical, physical and chemical properties. In this talk, our recent progress on Selective Laser Melting (SLM) of super metal powders for dense super metal parts is reported. The super metals produced by the additive manufacturing offers unprecedented material properties. The experimental study revealed the effects of nanoparticles and laser processing parameters on microstructure characteristics (distribution of nanoparticles, grain size, and phase morphology of the matrix) and material properties of super metals. Laser additive manufacturing of super metals expands the traditional layered manufacturing space for widespread applications to meet energy and sustainability challenges in today’s society.
2:30pm - 3:00pm Invited
Metal Micro-additive Manufacturing based on Parallel Femtosecond Laser Machining and Electrodeposition
The Chinese University of Hong Kong, Hong Kong S.A.R. (China)
In this work, we present a parallel laser machining method using femtosecond lasers for additively printing high precision metal devices via electrodeposition. To achieve parallel micromachining, a femtosecond laser is first projected to a DMD, which spatially disperses the spectrum into different directions. After a collimating lens, an objective lens recombines all the dispersed spectrum to the focal region, forming a high-intensity thin light sheet for micromachining. The patterns on the light sheet can be arbitrarily controlled by the DMD. Preliminarily, we processed a 1 micron thick electrodeposited nickel layer on a substrate with 40 pulses of 50mW over 100×60 µm2. Complex 3-D metal structures can be fabricated by repeating the micromachining and electrodeposition processes.
3:00pm - 3:15pm Oral
Nanotechnology Approach in Al Alloys Properties Improvement
Ariel University, Israel
The novel approach of influence on aluminum alloys structure formation by various nanomaterials (ceramic nano-powders, multi-walled and single-walled carbon nanotubes and inorganic nanotubes) affecting the solidification process will be discussed. Fine microstructure of the Al alloys has been obtained as the result of the direct influence of the added nanomaterials into the melt.
Modification process has been done using various approaches. It has been found that aluminum alloys mechanical properties improved after addition of relatively small amount (less than 1wt. %) of nanomaterials. Mechanical properties results will be discussed as well as strengthening mechanism which has been studied using high resolution transmission electron microscopy (HR-TEM).
3:15pm - 3:30pm Oral
Multi-Material Modelling for Selective Laser Melting
Jie Lun TAN, Chee How WONG, Anastassia SORKIN
Nanyang Technological University, Singapore
Selective Laser Melting (SLM) is a powder bed Additive Manufacturing (AM) process which uses a laser beam to fully melt the powders layer upon layer to build a 3D part. While most studies are conducted on SLM using single material, the application of multi-materials using this technology can offers more advantages than the conventional manufacturing methods. Complex mutli-materials parts can be built which conventional manufacturing methods are unable to due to their restriction in design of freedom. However, the SLM process has its own limitations in producing multi-material parts. Since SLM uses a powder bed to build parts, the use of different powder materials in the powder bed will result in contamination of the unused powder, rendering unnessary wastages.Therefore, using modelling techniques to attain the optimised parameters before conducting the actual experiment to verify its validity will aid in reducing wastages, leading to cost saving . To study the effects of the interface of different materials during the laser scanning, a model was simulated observe the melting process. An open-source LAMMPS (Large-scale Atomic Molecular Massively Parallel Simulator) software uses Molecular Dynamics (MD) model to project each powder particle using atoms. The materials used for the simualations are Iron (FE) and Aluminium (Al). The modelling is extended to multiple layers to allow the observation of the bonding between layers.