FRACTURE AND PLASTICITY AT THE NANOSCALES – IN SITU OBSERVATION DURING CLAMPED BEAM BENDING EXPERIMENTS of Cu/Nb NANOLAMINATES

When:
19/10/2018 @ 2:00 PM – 3:30 PM Asia/Singapore Timezone
2018-10-19T14:00:00+08:00
2018-10-19T15:30:00+08:00
Where:
The Physics conference room,S11-02-07
4 Science Drive 2
S11
Singapore 117544
FRACTURE AND PLASTICITY AT THE NANOSCALES – IN SITU OBSERVATION DURING CLAMPED BEAM BENDING EXPERIMENTS of Cu/Nb NANOLAMINATES @ The Physics conference room,S11-02-07 | Singapore | Singapore

Speaker: Dr. Arief Suriadi Budiman
Affiliation: Extreme Materials Laboratory (XML), Singapore University of Technology & Design (SUTD)
Host: Professor Barbaros Oezyilmaz
Location: Click HERE for directions

Abstract Details: Plastic deformation mechanisms in metal-metal nanolayer composites (nanolaminates) have been
studied extensively during the last decade, but their fracture responses (especially in an in situ set
up) have not been reported. It has been widely observed that, for the case of metal-metal
nanolaminates with a semicoherent interface, such as Cu/Nb, low interface shear strength
increases the interface barrier to dislocation crossing, which improves nanolaminate plasticity. In
this study, we use Cu(63nm)/Nb(63nm) accumulative roll-bonded nanolaminates, which have a
large anisotropy of the interface shear strength between rolling and transverse directions (RD and
TD, respectively), to study the effect of interface shear strength on the plasticity mechanisms and
fracture events leading to the final catastrophic failure in metal-metal nanolaminates with a
semicoherent interface during in situ clamped beam bending. Further, finite element analysis is
used to understand the observed behavior. The results show a substantial difference between the
fracture behaviors along the RD and TD owing to differences in the interface shear strength and
grain size. For the RD beams, the slip bands originate from the Nb layers at the notch/crack tip
followed by crack propagation along these bands. For the TD beams, the crack propagation is
inhibited by interface shear. The results reveal that low interface shear strength can be utilized to
improve fracture resistance in the studied nanolaminates, though weak grain boundaries can
suppress the interface shear and the associated crack resistance improvement. This knowledge
can be used to further optimize the nanolaminate fabrication process and achieve good strength,
ductility, and crack resistance at the same time.

About the Speaker: Arief Suriadi Budiman received his B.S. in mechanical engineering from Institute of Technology,
Bandung (ITB), Indonesia, his M.EngSc in materials engineering from Monash Univ., Australia and
his Ph.D. in Materials Science and Engineering from Stanford University, CA in 2008. During his
doctoral candidacy at Stanford’s Department of Materials Science & Engineering under the
supervision of Professor William D. Nix (MRS Von Hippel Award 2007), Dr. Budiman received
several research awards (MRS Graduate Silver Award 2006, MRS Best Paper 2006) and contributed
to several high-impact journal publications (Acta Materialia, Applied Physics Letters, Journal of
Electronic Materials). He gave two symposium invited talks as well in the MRS spring and fall
meetings in 2006. More recently Dr. Budiman has been awarded the prestigious Los Alamos
National Laboratory (LANL) Director's Research Fellowship to conduct top strategic research for
the energy and national security missions of the Los Alamos National Laboratory's. At the Center
for Integrated Nanotechnologies (CINT) at Los Alamos, Dr. Budiman’s research program involves
nanomaterials for extreme environments with potential applications in advanced energy systems
including for next-generation nuclear power reactors. Currently, at Singapore University of
Technology & Design (SUTD), Prof. Budiman is leading a dynamic, young group researching
nanomaterials and nanomechanics and their implications for extending the extreme limits of
materials as well as their applications in the next generation energy technologies (solar PV, extreme
environments, energy storage, etc.). His work has also recently received the famed Berkeley Lab
Scientific Highlights twice in May 2010 and June 2013 (the latter was for his novel, innovative
characterization technique that enables thin silicon solar PV technology). His deep expertise in the
synchrotron X-ray microdiffraction technique was also recently utilized to enable the first ever in
situ measurements of mechanical stresses in the 3-D through-silicon via (TSV) Cu interconnect
schemes in the world – the findings were reported in a publication in Microelectronics Reliability
(2012) and now one of the most highly cited references in the field of TSV/3D Interconnect stress
measurements. He has been invited to give invited lectures/seminars on 3D/TSV Interconnect in
various international conferences (including IEEE IITC 2012, AVS Thin Films Users Group 2012,
TMS Symposium for Emerging Interconnects and Packaging Technologies 2011 and SEMATECH
Workshop on 3D Interconnect Metrology at SEMICON 2011). Dr. Budiman has authored/coauthored
several high-impact journal publications (Acta Materialia, Solar Energy Materials & Solar
Cells, Materials Science Engineering A), and contributed a book chapter on “Electromigration in
Thin Films and Electronic Devices: Materials and Reliability,” Woodhead Publishing, Cambridge,
2011. He has also recently published a book “Probing Crystal Plasticity at the Nanoscales –
Synchrotron X-ray Microdiffraction” (Springer 2015). He has two U. S. Patents and one pending.