Nanoscratching meets nanoindentation

2016 ◽  
Vol 231 (6) ◽  
Author(s):  
Irina P. Shakhverdova ◽  
Marianne Reibold ◽  
Werner Kochmann ◽  
Peter Paufler
Keyword(s):  
Normal Load ◽  
Adhesion Forces ◽  
Hardness Testing ◽  
Ambient Conditions ◽  
High Carbon ◽  
Surface Layers ◽  
Significant Drop ◽  
Nano Structures ◽  
Scratch Tests ◽  
Hardness Values

AbstractA specimen of high-carbon nitrogen-doped steel has been synthesized to supplement previous studies on wootz-like steels. A comparison of different states of material as well as one of distinct methods of hardness testing has been performed. Electron microscopy of the specimens’ microstructure revealed nano-structuring similar to that observed with ancient sabers. Part of them was annealed so that the nano-structures dissolved. Nano-hardness values derived under ambient conditions from indentation as well as from scratch tests were determined and related to the microstructure prior to and after annealing. The disappearance of nanostructuring led to a significant drop of hardness. The ratio of indentation to scratch hardness proved a suitable indicator of hardening. From hardness as function of penetration depth and from friction as function of time and normal load various quantitative features of the mechanical properties and of the deformation process have been evaluated. When modeling friction, sliding and plowing parts have been distinguished quantitatively. Enhanced adhesion forces were attributed to surface layers.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

Atomic scale surface engineering of micro- to nano-sized pharmaceutical particles for drug delivery applications

Nanoscale ◽  
2017 ◽  
Vol 9 (32) ◽  
pp. 11410-11417 ◽  
Author(s):  
D. Zhang ◽  
M. J. Quayle ◽  
G. Petersson ◽  
J. R. van Ommen ◽  
S. Folestad
Keyword(s):  
Drug Delivery ◽  
Atomic Layer Deposition ◽  
Surface Engineering ◽  
Atomic Layer ◽  
Atomic Scale ◽  
Ambient Conditions ◽  
Surface Layers ◽  
Layer Deposition ◽  
Atomic Surface ◽  
Scale Surface

Few atomic surface layers via atomic layer deposition under near ambient conditions significantly altered dissolution and dispersion of pharmaceutical particles.

scholarly journals Effect of Preliminary Irradiation of 321 Steel Substrates with High-Intense Pulsed Ion Beams on Scratch Test Results of Subsequently Deposited AlN Coatings

Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1169
Author(s):  
Vladislav Tarbokov ◽  
Sergey Pavlov ◽  
Egor Smolyanskiy ◽  
Vladimir Uglov ◽  
Mikhail Slobodyan ◽  
...  
Keyword(s):  
Ion Beam ◽  
Energy Levels ◽  
Scratch Test ◽  
Future Research ◽  
Surface Layers ◽  
Emission Signal ◽  
Future Research Directions ◽  
Modified Surface ◽  
Scratch Tests ◽  
Steel Substrates

The paper presents the effect of irradiation of 321 steel substrates with a high-intense pulsed ion beam (HIPIB) on changes in functional properties of the surface layers and tribological characteristics of AlN coatings subsequently deposited above by the reactive magnetron sputtering method. The morphology of the modified surface layers, their microhardness and free surface energy levels are presented for different HIPIB energy densities. HIPIB irradiation of the substrates caused variations in the results of scratch tests combined with the acoustic emission signal processing. Their analysis has enabled concluding that the crack initiation threshold could be at least doubled for the studied coating/substrate system due to preliminary HIPIB irradiation. Finally, the obtained data were discussed, and future research directions were proposed.

Friction Characteristics and Adhesion Force Under Low Normal Load

1995 ◽  
Vol 117 (4) ◽  
pp. 569-574 ◽  
Author(s):  
Yasuhisa Ando ◽  
Yuichi Ishikawa ◽  
Tokio Kitahara
Keyword(s):  
Friction Coefficient ◽  
Friction Force ◽  
Adhesion Force ◽  
Normal Load ◽  
Adhesion Forces ◽  
Test Pieces ◽  
Before And After ◽  
Constant Normal Load ◽  
The Mean ◽  
Steel Balls

The friction coefficient and adhesion force between steel balls and flat test pieces were measured during friction under low normal load in order to examine the tribological characteristics. First, the friction coefficients were measured under a constant normal load of 0.8 to 2350 μN, and the adhesion forces were measured before and after each friction. The result showed that the friction coefficient was highest at low normal loads, while the friction force divided by the sum of the normal load and the mean adhesion force was almost constant over the whole range of loads. Second, when the normal load was reduced gradually during friction, friction still acted when the normal load became negative and a pulling off force was applied to the surface. Thus an adhesion force acts during friction and this adhesion force affects the friction force in the same way as the normal load.

scholarly journals Effect of Nanobainite Content on the Dry Sliding Wear Behavior of an Al-Alloyed High Carbon Steel with Nanobainitic Microstructure

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1618 ◽  
Author(s):  
Zhaohuan Song ◽  
Songhao Zhao ◽  
Tao Jiang ◽  
Junjie Sun ◽  
Yingjun Wang ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Carbon Steel ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Normal Load ◽  
High Carbon Steel ◽  
Peak Hardness ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
High Carbon

In this work, a multiphase microstructure consisting of nanobainte, martensite, undissolved spherical carbide, and retained blocky austenite has been prepared in an Al-alloyed high carbon steel. The effect of the amount of nanobainite on the dry sliding wear behavior of the steel is studied using a pin-on-disc tester with loads ranging from 25–75 N. The results show that, there is no significant differences in specific wear rate (SWR) for samples with various amounts of nanobainite when the normal load is 25 N. While, the SWR firstly decreases and then increases with increasing the amount of nanobainite, and the optimum wear resistance is obtained for samples with 60 vol.% nanobainite, when the applied load increases to 50 and 75 N. The improved wear resistance is attributed to the peak hardness increment resulted from the transformation of retained austenite to martensite, work hardening, along with amorphization and nanocrystallization of the worn surface. In addition, the highest toughness of the samples with 60 vol.% nanobainite is also proven to play a positive role in resisting sliding wear. EDS (energy dispersion spectrum) and XRD (X-ray diffraction) examinations reveal that the predominant failure mechanism is oxidative wear.

Microstructure and Properties of Surface Nanostructured Copper

2011 ◽  
Vol 328-330 ◽  
pp. 1606-1609
Author(s):  
Wan Ming Lin ◽  
Yin Hui Wei ◽  
Li Feng Hou
Keyword(s):  
Copper Plate ◽  
Surface Mechanical Attrition Treatment ◽  
Hardness Testing ◽  
Surface Layers ◽  
Materials Properties ◽  
Transmission Electron ◽  
Mechanical Attrition ◽  
The Matrix ◽  
Novel Method ◽  
Potentiodynamic Anodic Polarization

Surface nanocrystallization (SNC) is a novel method for improving materials properties. Nanostructured surface layers of about 20 μm thickness were produced in copper plate samples by means of surface mechanical attrition treatment (SMAT). The behaviors of the SMAT samples were investigated by using transmission electron microscopy (TEM), Vickers hardness testing and potentiodynamic anodic polarization tests. The experimental results showed that the longer the peening time was performed on the copper pate samples, the thicker the deformation layers formed. The microhardness results for the top surface layer of the copper plate sample are 1.723 GPa and 1.752 GPa for 45 and 60 min, respectively, which are about two times higher than that of the matrix. The primary passivate potential of nanocrystalline copper was more negative than that of coarse-grain copper.

Microscratci I Test on Carbon Films as Thin as 20 nm

1990 ◽  
Vol 188 ◽  
Author(s):  
T. W. Wu ◽  
A. L. shull ◽  
J. Lin
Keyword(s):  
Acoustic Emission ◽  
Large Scale ◽  
Normal Load ◽  
Tangential Force ◽  
Carbon Films ◽  
Small Scale ◽  
Scale Spallation ◽  
First Occurrence ◽  
20 Nm ◽  
Scratch Tests

ABSTRACTThe capabilities to monitor tangential force and acoustic emission have been added to the microscratch mode of the IBM microindenter. These two new monitoring devices combined with the existing normal loadcell enhance the ability of the microscratch test to measure mechanical properties of thin film materials. As a demonstration of the upgraded microindenter, scratch tests were performed on 11 0nm and 20nm thick carbon films deposited on Si <100> substrates. The scratch morphology was examined by scanning electron microscopy to correlate the mechanical data to corresponding failure mechanisms.In the case of the 110nm film, a brittle type fracture was taking place as the applied normal load exceeded a critical value. All three monitored outputs detected the first occurrence of the spallation ofthe film. In contrast to the thicker film, large scale spallation was not observed for thle 20nm film, and the acoustic emission detector did not show any significant output. An apparent friction coefficient(FR) is defined as the ratio ofthe tangential force to the normal load. FR is determined to be a useful parameter for monitoring the indenter's transition through the coating into the substrate, particularly in the case of small scale fracturing or simple ploughing through types of failure.

Hardness Testing of Vulcanized Elastomers

1945 ◽  
Vol 18 (2) ◽  
pp. 448-451
Keyword(s):  
Class Ii ◽  
Constant Load ◽  
Hardness Testing ◽  
Shaped Body ◽  
Hardness Values

Abstract This report summarizes the various types of hardness determinations used for vulcanized elastomers. The chart is handy for conversions of hardness values obtained from one type of instrument to another. The various types of instruments used to determine hardness can be divided into two classes: I. Instruments operating under constant load. The majority of instruments fall in this class. II. Instruments operating with a spring. These are the simplest to operate and are pocket-size instruments. In both cases hardness is determined by the depth to which a definite-shaped body dents the vulcanizate under a controlled load.

Effect of Operating Variables With Heat Treatment and Their Interactions on Wear Behavior of High Carbon Steels in Dry Sliding

Tribology ◽  
2005 ◽  
Author(s):  
Aimen M. Younis ◽  
Ahmed A. Akbar
Keyword(s):  
Heat Treatment ◽  
Wear Behavior ◽  
Normal Load ◽  
Carbon Steels ◽  
Main Mechanism ◽  
Wear Loss ◽  
Dry Sliding ◽  
Sliding Velocity ◽  
High Carbon ◽  
Operating Variables

The present study deals with the wear data analysis of high carbon steels to investigate the relationship between the operating variables and the heat treatment. The steel selected was 1095 in the AISI standard which is equivalent to C105W1 in the German standard. The wear studies were carried out by using pin on disc apparatus at room temperature in dry sliding. The wear data were carried out based on an experimental design (24 factorial design ) following by analysis of variance method (ANOVA) to examine the main effect of sliding velocity, normal load, sliding distance, heat treatment, and their interactions on wear behavior. The results show that severe deformation of annealed and quenched 1095 steels on the contact surface was responsible for high wear loss at high normal loads and low sliding velocities. At high normal load and low sliding velocity, severe wear by oxidative-metallic was main mechanism and at low normal load for the same sliding velocity, mild wear by oxidative was main mechanism. The ANOVA results show that the operating variables have more significant effect on wear loss than that of heat treatment.

Nitrogen Effect on Mechanical and Tribological Properties of STN 41 5230 Steel Surface Layer

2014 ◽  
Vol 1059 ◽  
pp. 11-17
Author(s):  
Ivan Kováč ◽  
Rastislav Mikuš ◽  
Jozef Žarnovský ◽  
Juraj Ružbarský
Keyword(s):  
Surface Layer ◽  
Diffusion Processes ◽  
Base Material ◽  
Material Surface ◽  
Surface Layers ◽  
Mechanical And Tribological Properties ◽  
Nitrogen Effect ◽  
A Tig Welding ◽  
The Subject ◽  
Hardness Values

The subject-matter of this article is using diffusion processes to obtain chemically stable compounds with a low reactivity and higher mechanical properties in material surface layer. These processes were implemented by remelting the surface of a given material in arc process using a TIG welding method. Nitrogen was used as an alloying element in experiments. The experiment assumed that the dissociation and ionization of gases, enabling the ionization of diffusion processes in the surface layer of remelted steel, will be achieved by means of electric arc. Conditions for the formation of hard and stable structures with required properties should have been created by enriching the surface layer. The STN 41 5230 steel was used in experiments. After remelting, samples were examined on hardness and relative abrasive wear resistance, which are crucial in terms of required properties of given surface layers. In addition to hardness values in the surface layer, also its behaviour inwards the material up to thermally unaffected base material was determined. When remelting in the environment containing nitrogen, the values of examined quantities increased.

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