|
Prof. Mikio
Ito
Fukui University
of Technology |
Speech Title: Fabrication
of Diamond Particle Dispersed Metal Matrix Composites by Spark Plasma
Sintering(SPS) for high thermal conductive materials
Abstract: TBA
Biography: Prof.
Mikio Ito received B.E., M.E, and Dr.E degrees from Osaka University. He
was an assistant professor and associate professor at Osaka University,
and is now a professor of Department of Mechanical Engineering, Fukui
University of Technology. His research interests include development of
novel powder metallurgy process, especially for sintering process, and
improvement of various powder-metallurgy-processed functional materials,
such as thermoelectric and hard magnetic materials, etc. |
|
Prof. Chih-Lang
Lin
Central Taiwan University of Science and Technology |
Speech Title: Study of the Factors on Controlling Cured Layer Thickness
in DLP 3D Printing
Abstract: Digital
Light Processing (DLP) 3D printing is an additive manufacturing
technique that uses a digital light projector to cure photopolymer resin
layer-by-layer to create high-precision solid structures. In addition to
the planar resolution, the control of curing depth has a critical impact
on the success of precise printing and the geometric features of the
printed product. This issue is aggravated in the case of projection
micro-stereolithography (PμSL), which uses an objective lens to enhance
the planar resolution of the projected pattern. In this study, we
investigated possible measures to control the cured layer thickness from
both material and optical perspectives. As-received commercial resin was
used to obtain the raw cured layer thickness, and then Sudan I or carbon
black was added separately to study their effects. Eventually, the
grayscale of the exposed pattern was adjusted to reduce light intensity
and achieve a thinner layer thickness. Combining the above measures
reduced the single-layer cured thickness from the raw 250 μm to 5.8 μm,
approaching the usual minimum layer dimension setting of 5 μm. By
exploring the variables affecting cured layer thickness, this study is
expected to improve DLP 3D printing technology in producing high
resolution structures.
Biography: Dr.
Chih-Lang Lin got his master’s degree in Power Mechanical Engineering
from National Tsing-Hua University. He earned his Ph.D. in Mechanical
Engineering from National Taiwan University. In the mean while, he
earned another Ph.D. in Physics of Condensed Material and Radiation from
Joseph Fourier University, France. His thesis involves two subjects
which are fiber Bragg grating (FBG) sensors and laser driven
microsensors. In the first part, a framework for the interpretation of
reflected FBG spectra under a non-uniform strain field is proposed and
experimental results for a crack tip strain field are presented. In the
second part, the fabrication of laser driven polymer microsensors for
visconsimetry, velocimetry and micropump applications are developed.
Before he created the Bio-Photonics Lab at Central Taiwan University of
Science and Technology, he joined Air Liquide international group to
work in Japan as a researcher (TFT/LCD group) and in Taiwan as an
operation manager/factory director. One of Dr. Lin’s research interests
is laser driven micromachines. He proposed a serious of elemental
micromachines, such as cantilever, lever beam, spring, Archimedes
screw…etc. His another interest is the fabrication of three-dimensional
structured protein using two-photon polymerization technology for
detecting bio-cells such as bacteria, red blood cells, and cancer cells.
Also, he studied the bio-mechanics of cells by using optical tweezers
for the clinical diagnosis. The above subjects were expected to
contribute to the application of point-of-cares. More recently, he
starts to implement the intelligent manufacture by the 3D printing
technique. |
|
Assoc. Prof. Go
Yamamoto
Tohoku University
|
Speech Title: Can
strength prediction methods based on continuum mechanics be applied for
unidirectional carbon nanotube yarn reinforced plastic composites?
Abstract: Carbon
nanotubes (CNTs) having a high elastic modulus and tensile strength are
anticipated for use as a reinforcing agent in fiber reinforced
composites. Recently, the focus has shifted to investigating the
fracture mechanisms of CNT yarns, which are twisted together to form
long threads of CNTs, particularly in polymer matrix environments. In
this study, the interaction between CNT yarns in polymer matrix
environment under tensile loading was observed using the X-ray computed
tomography (CT) method at the synchrotron radiation facility, SPring-8.
Double-fiber fragmentation specimens were prepared by positioning two
yarns parallel to the loading direction, implementing an inter-yarn
spacing of within 20 μm. X-ray CT nanoimaging revealed that the CNT
yarns fractured closely together in the direction of the long axis of
the CNT yarns. This implies that stress concentration occurred in the
adjacent CNT yarn due to the fracture of the CNT yarn, as observed for
unidirectional carbon fiber reinforced plastic (CFRP) composites.
Moreover, the fracture surfaces of the individual CNT yarns were
observed to be separated by the relative slippage of CNT bundles. The
matrix crack propagated longitudinally within the CNT yarns, taking a
helical path through the matrix. Our findings revealed that stress
concentration on the adjacent CNT yarn is expected to occur, providing
valuable insight into the similarity of the failure mechanisms between
unidirectional CNT yarn composites and unidirectional CFRPs.
Biography: Dr.
Go Yamamoto obtained his PhD degree from Tohoku University (Japan) in
2006. He is currently an Associate Professor in Department of Aerospace
Engineering, Tohoku University, Japan. His group research interests
include (1) Tensile strength prediction of carbon fiber reinforced
plastic composites, (2) Determination of elastic constants of materials
with intricate 3D geometries and mechanical anisotropy, and (3)
Development of defect detection method by using topology optimization.
Some of the work has been published in Composites Part A, Carbon, and
Nanotechnology, among others. |