Study for the Effect of Continuously Applied Load on a Compressed Ag Nanoparticle at Room Temperature by Atomic Scale Simulations

2016 ◽  
Vol 85 (5) ◽  
pp. 054602 ◽  
Author(s):  
Lin Zhang
Keyword(s):  
Room Temperature ◽  
Applied Load ◽  
Atomic Scale ◽  
Ag Nanoparticle

Thermal Effects on the Friction of Sliding Rough Surfaces

2011 ◽  
Author(s):  
Peter Spijker ◽  
Guillaume Anciaux ◽  
Jean-Franc¸ois Molinari
Keyword(s):  
Molecular Dynamics ◽  
Thermal Effects ◽  
Large Scale ◽  
Room Temperature ◽  
Applied Load ◽  
Close Contact ◽  
Rough Surfaces ◽  
Md Simulations ◽  
Atomic Scale ◽  
Deformable Bodies

We use large-scale molecular dynamics (MD) simulations to model the sliding of deformable bodies in close contact, where both bodies have self-affine rough surfaces at the atomistic level. We keep both bodies at room temperature, while changing the surface roughness and the applied load. We compared our current results with similar cases at zero Kelvin and find surprisingly that a mild thermal increase from 0 to 300 K of the material enhances friction at the atomic scale.

Direct Nanoscale Patterning by Atomic Manipulation

1995 ◽  
Vol 380 ◽  
Author(s):  
Craig T. Salling
Keyword(s):  
Scanning Tunneling Microscope ◽  
Room Temperature ◽  
Atomic Layer ◽  
Sample Surface ◽  
Atomic Scale ◽  
Scanning Tunneling ◽  
Nanoscale Patterning ◽  
Direct Patterning ◽  
Scale Structures ◽  
Atomic Manipulation

ABSTRACTThe ability to create atomic-scale structures with the scanning tunneling microscope (STM) plays an important role in the development of a future nanoscale technology. I briefly review the various modes of STM-based fabrication and atomic manipulation. I focus on using a UHV-STM to directly pattern the Si(001) surface by atomic manipulation at room temperature. By carefully adjusting the tip morphology and pulse voltage, a single atomic layer can be removed from the sample surface to define features one atom deep. Segments of individual dimer rows can be removed to create structures with atomically straight edges and with lateral features as small as one dimer wide. Trenches ∼3 nm wide and 2–3 atomic layers deep can be created with less stringent control of patterning parameters. Direct patterning provides a straightforward route to the fabrication of nanoscale test structures under UHV conditions of cleanliness.

Atomic-scale structural evolution in amorphous Nd9Fe85B6 subjected to severe plastic deformation at room temperature

2009 ◽  
Vol 94 (23) ◽  
pp. 231904 ◽  
Author(s):  
Wei Li ◽  
Xiaohong Li ◽  
Defeng Guo ◽  
Kiminori Sato ◽  
Dmitry V. Gunderov ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Room Temperature ◽  
Structural Evolution ◽  
Atomic Scale

Sintering of Silver Nanoparticles at Room-Temperature for Conductive Ink Applications

2018 ◽  
Vol 775 ◽  
pp. 144-148 ◽  
Author(s):  
Bethel Faith Y. Rezaga ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Particle Size ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Average Diameter ◽  
Aqueous System ◽  
Ag Nanoparticle ◽  
Nacl Solution ◽  
Cellulose Acetate Film ◽  
Sintered Ag ◽  
Nanoparticle Ink

Silver (Ag) nanoparticles synthesized in an aqueous system was sintered at room temperature using NaCl solution. The Ag nanoparticles have an average diameter of about 24 nm. After dispersing the Ag nanoparticles in 50mM NaCl solution, a significant increase in particle size to about 206 nm was observed. On the other hand, the particle size was also increased to about 175 nm when the Ag nanoparticles were printed and then 50mM NaCl solution was dropped onto the printed Ag nanoparticles. The enlargement of particle size was accompanied by the increase in conductivity of the Ag nanoparticle ink. The resistance was reduced from 57.7 to 6.5 and 6.7 ohms for the as-prepared and sintered Ag nanoparticles using two different treatments, respectively. The sintered Ag nanoparticle ink formulation exhibit high conductivity when drawn on both cellulose acetate film and bond paper even after bending and folding of the substrates.

Fusing of Silver Nanoparticles at Room Temperature Using Halide Solutions for Conductive Inks

2020 ◽  
Vol 833 ◽  
pp. 181-185 ◽  
Author(s):  
Bethel Faith Y. Rezaga ◽  
Mary Donnabelle L. Balela
Keyword(s):  
Particle Size ◽  
Ag Nanoparticles ◽  
Room Temperature ◽  
Average Diameter ◽  
Aqueous System ◽  
Ag Nanoparticle ◽  
Nacl Solution ◽  
Halide Solution ◽  
Sintered Ag ◽  
Nanoparticle Ink

Fusing of silver (Ag) nanoparticles synthesized in an aqueous system was observed at room temperature using halide solutions. The as-synthesized Ag nanoparticles have an average diameter of about 24 nm. After dispersing the Ag nanoparticles in a halide solution, a significant increase in particle size to about 188-197 nm was observed. The enlargement of particle size was accompanied by the increase in conductivity of the Ag nanoparticle ink. The resistance was reduced from 110 kiloohms to 35 and 9.3 ohms for the as-prepared and sintered Ag nanoparticles using NaBr and NaCl solution, respectively.

scholarly journals In Situ Atomic-Scale Observation of Dislocation Climb and Grain Boundary Transformation in Nanostructured Metal

2021 ◽  
Author(s):  
Shufen Chu ◽  
Pan Liu ◽  
Yin Zhang ◽  
Xiaodong Wang ◽  
Shuangxi Song ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Grain Boundary ◽  
Room Temperature ◽  
Atomic Plane ◽  
Dislocation Core ◽  
Dislocation Climb ◽  
Atomic Scale ◽  
Atomic Column ◽  
Nanostructured Metal

Abstract We report atomic-scale observations of grain boundary (GB) dislocation climb in nanostructured Au during in situ straining at room temperature. Climb of a dislocation occurs by stress-induced reconstruction of two atomic columns at the edge of an extra half atomic plane in the dislocation core. Different from the conventional belief of dislocation climb by destruction or construction of a single atomic column at the dislocation core, the new atomic route is demonstrated to be energetically favorable by Monte Carlo simulations. Our in situ observations also reveal GB transformation through dislocation climb, which suggests a means of controlling microstructures and properties of nanostructured metals.

scholarly journals HOT HARDNESS MEASUREMENTS ON MATERIALS UP TO 600 °C DURING THE FIRST HOUR OF USING

2020 ◽  
Vol 27 ◽  
pp. 160-163
Author(s):  
Bruno Passilly ◽  
Lara Molenda
Keyword(s):  
Room Temperature ◽  
Applied Load ◽  
Vickers Microhardness ◽  
Maximum Load ◽  
Operating Environment ◽  
Simple Method ◽  
Micromechanical Characterization ◽  
Temperature Test ◽  
Conditions Of Employment ◽  
Hot Hardness

In the aeronautical field, materials are used in severe environmental conditions (temperature, atmosphere, exposure time ...), particularly for engine applications. In order to characterize the use of these materials in the evaluation of their properties, it is necessary to carry out tests in conditions close to their operating environment. Hot hardness is a simple method which can be applied on many different materials such as oxidized layers, coatings, composite materials, brazing cords, additive manufacturing materials. ONERA is developing micromechanical characterization means to carry out Vickers microhardness tests from room temperature up to 600 °C. In principle, a pyramidal punch is applied on the surface of a material and the applied load is continuously measured during indenter’s moving in the material. The material is tested locally under conditions close to the actual conditions of employment. The goal of this research is to improve microindentation in order to achieve temperature test campaigns up to 600 °C under a controlled atmosphere of argon and to validate a method to produce a series of results during the first hour of using up to 600 °C. Stainless material is studied to compare the evolution of its hot hardness properties versus different parameters such as load, holding time at the maximum load, atmosphere, and thermal duration. A discussion about these measurements and the technical limits of hot hardness technology is presented.

scholarly journals High Temperature Hardness of Bulk Single Crystal GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 343-348
Author(s):  
I. Yonenaga ◽  
T. Hoshi ◽  
A. Usui
Keyword(s):  
High Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Applied Load ◽  
Elevated Temperatures ◽  
Mechanical Stability ◽  
Bulk Single Crystal ◽  
Indentation Method ◽  
First Time ◽  
High Mechanical Stability

The hardness of single crystal GaN (gallium nitride) at elevated temperature is measured for the first time and compared with other materials. A Vickers indentation method was used to determine the hardness of crack-free GaN samples under an applied load of 0.5N in the temperature range 20 - 1200°C. The hardness is 10.8 GPa at room temperature, which is comparable to that of Si. At elevated temperatures GaN shows higher hardness than Si and GaAs. A high mechanical stability for GaN at high temperature is deduced.

HREM observation of interface between precipitates and martensite of reversible shape memory alloy Ni-Ti

1991 ◽  
Vol 49 ◽  
pp. 596-597
Author(s):  
Zhiyi Song ◽  
Hatsujiro Hashimoto ◽  
Eiichi Sukedai
Keyword(s):  
Electron Microscopy ◽  
Shape Memory ◽  
Room Temperature ◽  
Atomic Scale ◽  
Martensitic Transformation Temperature ◽  
Microscopy Observation ◽  
Resolution Electron ◽  
Interface Structures ◽  
The Relationship ◽  
Martensite Structure

Since the reversible shape memory (RSM) alloys were found in 1960, a number of investigations and applications have been carried out and the mechanism have been discussed extensively. Ni-Ti is one of the typical RSM alloys. Many researches were concentrated on martensite structure and the relationship between martensite and austenite. However, the interface structures between martensite and precipitates have been rarely studied. In the present paper, the interface structures between precipitates ( NiTi2 and Ni3Ti) and martensite were investigated in atomic scale by using nigh resolution electron microscopy.49.5at%Ni-50.5at%Ti alloy whose martensitic transformation temperature is 75°C was annealed at 900°C for 2 hours to allow the components to become uniformly distributed, then quenched into water at room temperature. The specimens for electron microscopy observation were prepared by spark cutting and electropolishing. A JEM-2000EX and JEM-4000EX operated at 200kv and 400kv, respectively were used in the present observations.

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