Mechanical Fracturing of Core-Shell Undercooled Metal Particles for Heat-Free Soldering

Çınar, Simge
Chen, Jiahao
Thuo, Martin
Phase-change materials, such as meta-stable undercooled (supercooled) liquids, have been widely recognized as a suitable route for complex fabrication and engineering. Despite comprehensive studies on the undercooling phenomenon, little progress has been made in the use of undercooled metals, primarily due to low yields and poor stability. This paper reports the use of an extension of droplet emulsion technique (SLICE) to produce undercooled core-shell particles of structure; metal/oxide shell-acetate ('/'=physisorbed, '-'=chemisorbed), from molten Field's metal (Bi-In-Sn) and Bi-Sn alloys. These particles exhibit stability against solidification at ambient conditions. Besides synthesis, we report the use of these undercooled metal, liquid core-shell, particles for heat free joining and manufacturing at ambient conditions. Our approach incorporates gentle etching and/or fracturing of outer oxide-acetate layers through mechanical stressing or shearing, thus initiating a cascade entailing fluid flow with concomitant deformation, combination/alloying, shaping, and solidification. This simple and low cost technique for soldering and fabrication enables formation of complex shapes and joining at the meso-and micro-scale at ambient conditions without heat or electricity.


Optical and mechanical properties of fiber-reinforced ceramic matrix optically transparent composites
Dericioğlu, Arcan Fehmi (2001-12-01)
The idea of increasing the fracture resistance of optically transparent Ceramics by incorporation of continuous fibers with a small expense in their light transmission was applied to a SiC (SCS-6) fiber-reinforced magnesium aluminate spinel matrix composite. It was found that although there is a slight decrease in the light transmittance of the transparent monolithic matrix with increasing fiber volume fraction, a fail-safe mechanism appeared in the composite by the bridging effect of the intact fibers
Novel topological nodal lines and exotic drum-head-like surface states in synthesized CsCl-type binary alloy TiOs
Wang, Xiaotian; Ding, Guangqian; Cheng, Zhenxiang; Surucu, Gokhan; Wang, Xiao-Lin; Yang, Tie (Elsevier BV, 2020-03-01)
Very recently, searching for new topological nodal line semimetals (TNLSs) and drum-head-like (DHL) surface states has become a hot topic in the field of physical chemistry of materials. Via first principles, in this study, a synthesized CsCl type binary alloy, TiOs, was predicted to be a TNLS with three topological nodal lines (TNLs) centered at the X point in the k(x/y/z) = pi plane, and these TNLs, which are protected by mirror, time reversal (T) and spatial inversion (P) symmetries, are perpendicular to...
Nanoparticle self-assembly at the interface of liquid crystal droplets
Rahimi, Mohammad; Roberts, Tyler F; Armas-Pérez, Julio C; Wang, Xiaoguang; Büküşoğlu, Emre; Abbott, Nicholas L; de Pablo, Juan Jose (Proceedings of the National Academy of Sciences, 2015-04-28)
Nanoparticles adsorbed at the interface of nematic liquid crystals are known to form ordered structures whose morphology depends on the orientation of the underlying nematic field. The origin of such structures is believed to result from an interplay between the liquid crystal orientation at the particles' surface, the orientation at the liquid crystal's air interface, and the bulk elasticity of the underlying liquid crystal. In this work, we consider nanoparticle assembly at the interface of nematic drople...
Direct Visualization of the Hydration Layer on Alumina Nanoparticles with the Fluid Cell STEM in situ
FIRLAR, Emre; Çınar, Simge; KASHYAP, Sanjay; AKINC, MÜFİT; PROZOROV, Tanya (Springer Science and Business Media LLC, 2015-05-21)
Rheological behavior of aqueous suspensions containing nanometer-sized powders is of relevance to many branches of industry. Unusually high viscosities observed for suspensions of nanoparticles compared to those of micron size powders cannot be explained by current viscosity models. Formation of so-called hydration layer on alumina nanoparticles in water was hypothesized, but never observed experimentally. We report here on the direct visualization of aqueous suspensions of alumina with the fluid cell in si...
Numerical and Experimental Investigation into LWIR Transmission Performance of Complementary Silicon Subwavelength Antireflection Grating (SWARG) Structures
Cetin, Ramazan; Akın, Tayfun (Springer Science and Business Media LLC, 2019-03-18)
This paper presents a detailed comparison between the long wave infrared (LWIR) transmission performances of binary, silicon based, structurally complementary pillar and groove type antireflective gratings that can be used for wafer level vacuum packaging (WLVP) of uncooled microbolometer detectors. Both pillar and groove type gratings are designed with various topological configurations changing in various period sizes (Delta) from 1.0 mu m to 2.0 mu m, various heights/depths (h) from 0.8 mu m to 1.8 mu m,...
Citation Formats
S. Çınar, J. Chen, and M. Thuo, “Mechanical Fracturing of Core-Shell Undercooled Metal Particles for Heat-Free Soldering,” SCIENTIFIC REPORTS, pp. 0–0, 2016, Accessed: 00, 2020. [Online]. Available: