An Experimental Study of the Nano-Scratch Behavior of Cement Composite Material

2011 ◽  
Vol 492 ◽  
pp. 47-54 ◽  
Author(s):  
Jing Xu ◽  
Wu Yao
Keyword(s):  
Composite Material ◽  
Coefficient Of Friction ◽  
Cement Composite ◽  
Scratch Test ◽  
Cement Clinker ◽  
Plastic Behavior ◽  
Soft Matrix ◽  
Elastic Plastic ◽  
The Coefficient Of Friction ◽  
Nano Scratch Test

This paper presents a preliminary exploration in tribological property and dynamic elastic/plastic behavior of cement composite material at micro- and nano- scale. Pastes were prepared by pure cement clinker with water-to-cement ratio of 0.3 and 0.4. For comparison, a polymer-based clinker composite was also introduced. Nano-scratch test was carried out to study the scratch process. Different constituents were identified by penetration depth value. Based on this identification, the coefficient of friction and elastic deformation status were analyzed. Substrate effect was found when refers to the coefficient of friction of hard clinker particles embedded in soft matrix. An H/E ratio dependent elastic/plastic behavior was also revealed for cement composite. The results confirm the nano-scratch test as a promising method for cement composite investigation; however, some important attributes of this type of material, including the complexity of multi-phase structure and the viscous effect, need to be taken into account in experimental analysis and practical application.

Deformation mechanism and tribological behavior of hydrogen-free carburized layer on Ti-6Al-4V alloy

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tian Tian ◽  
Ruibo Zhao ◽  
Dongbo Wei ◽  
Kai Yang ◽  
Pingze Zhang
Keyword(s):  
Peer Review ◽  
Deformation Mechanism ◽  
Tribological Behavior ◽  
Scratch Test ◽  
Hardness Profile ◽  
Cross Sectional ◽  
Content Type ◽  
Elastic Plastic ◽  
The Coefficient Of Friction ◽  
Carburized Layer

Purpose The purpose of this paper is to expound the relationship among microstructure, mechanical property, tribological behavior and deformation mechanism of carburized layer deposited on Ti-6Al-4V alloy by double-glow plasma hydrogen-free carburizing surface technology. Design/methodology/approach Morphologies and phase compositions of the carburized layer were observed by scanning electron microscope and X-ray diffraction. The micro-hardness tests were used to evaluate the surface and cross-sectional hardness of carburized layer. The reciprocating friction and wear experiments under various load conditions were implemented to investigate the tribological behavior of carburized layer. Moreover, scratch test with ramped loading pattern was carried out to illuminate the deformation mechanism of carburized layer. Findings Compared to substrate, the hardness of surface improved to ∼1,100 HV0.1, while the hardness profile of carburized layer presented gradual decrease from ∼1,100 to ∼300 HV0.1 within the distance of the total carburizing-affected region about 30 µm. The coefficient of friction, wear rate and wear morphology of carburized layer were analyzed. Scratch test indicated that the deformation process of carburized layer could be classified into three mechanisms (elastic, changing elastic–plastic and stable elastic–plastic mechanisms), and the deformation transition of the carburizing-affected region was from changing elastic–plastic to elastic mechanisms. Both the elastic and changing elastic–plastic mechanisms are conducive to the wearing course. Originality/value Using this technology, hydrogen embrittlement was avoided and wear resistance property of titanium alloy was greatly improved. Simultaneously, the constitutive relation during the whole loading process was deduced in terms of scratch approach, and the deformation mechanism of carburized layer was discussed from a novel viewpoint. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-11-2019-0489/

Scratch Resistance of the Si3N4-Graphene Nanoplatelets Composites

2015 ◽  
Vol 662 ◽  
pp. 165-168
Author(s):  
Monika Kašiarová ◽  
Monika Michalková ◽  
Ján Dusza ◽  
Pavol Šajgalík
Keyword(s):  
Silicon Nitride ◽  
Crack Propagation ◽  
Coefficient Of Friction ◽  
Applied Load ◽  
Scratch Test ◽  
Scratch Resistance ◽  
Graphene Nanoplatelets ◽  
Hot Press ◽  
The Coefficient Of Friction ◽  
Hot Press Sintering

The scratch resistance of the silicon nitride with the addition of 1 and 7 wt% of graphene multiplatelets prepared by hot press sintering has been studied. The scratch resistance behaviour of Si3N4-GNP composites were investigated using a Rockwell indenter for normal applied loads ranging from 1-150 N. Si3N4-7-wt%GNP composite behaved differently during the scratch test depending on the normal applied load. The coefficient of friction changed dramatically at higher load and extensive crack propagation resulting in the chipping is observed.

scholarly journals Effect of Bulk Current Density on Tribological Properties of Fe-W, Co-W and Ni-W Coatings

2015 ◽  
Author(s):  
S.A. Silkin ◽  
A.V. Gotelyak ◽  
N. Tsyntsaru ◽  
A.I. Dikusar ◽  
R. Kreivaitis ◽  
...  
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Current Density ◽  
Dry Friction ◽  
Scratch Test ◽  
Tribological Behaviour ◽  
The Coefficient Of Friction ◽  
Current Densities ◽  
Scratch Tests ◽  
The Given

Evaluation of tribological behaviour of Fe-W, Ni-W and Co-W coatings produced by electrodeposition at various bulk current densities (BCD) was under investigation in the given study. BCD does not have essential effect on the microhardness and wear characteristics of Fe-W and Co-W coatings. But the scratch tests reveal the presence of such influence. These tests showed superior wear resistance for the coatings obtained at low BCD. It was found that BCD has influence on wear resistance of Ni-W coatings under dry friction conditions. The BCD also has an influence on the coefficient of friction of Fe-W and Ni-W coatings at dry friction conditions. However, such an effect is opposite to that, observed at the scratch test.

scholarly journals Mechanical and Tribological Characterization of a Dental Ceromer

2020 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
Mariana Santos ◽  
Ana Sofia Coelho ◽  
Anabela Baptista Paula ◽  
Carlos Miguel Marto ◽  
Inês Amaro ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Test Group ◽  
Scratch Test ◽  
Composite Resins ◽  
Control Group ◽  
Posterior Teeth ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Tribological Characterization

Background: Indirect restorations using composites with ceramic fillings can be an alternative to ceramic veneering and direct composite restorations for the treatment of posterior teeth. The aim of this study was the evaluation of the mechanical and tribological properties of a ceromer. Materials and Methods: Sixty specimens were produced and divided into two groups: one control group not submitted to thermocycling (n = 20) and one test group submitted to 5000 cycles of thermocycling (n = 40). The studied parameters were microhardness, surface roughness and the coefficient of friction (scratch test). Results: The ceromer exhibits a reduction of polymerization shrinkage, higher wear, and fracture resistance than the composite resins. The studied ceromer presented good mechanical properties, even after being submitted to thermocycling. Roughness was the property most affected, increasing 25.8%, microhardness decreased by 10.5% and the coefficient of friction increased by 4.2%. Conclusions: In certain situations, ceromers can be an alternative to composite resins and ceramics, providing an aesthetic, conservative and longevity option.

HIGH-TEMPERATURE OXIDATION, MECHANICAL, AND TRIBOLOGICAL PROPERTIES OF ELECTROPLATED Cr COATING ON STEEL AFTER ANNEALING IN 700∘C

2018 ◽  
Vol 25 (08) ◽  
pp. 1950032
Author(s):  
DANIEL KOTTFER ◽  
TOMÁŠ ROCH ◽  
LUKASZ KACZMAREK ◽  
MAREK VOJTKO ◽  
MARTA KIANICOVÁ ◽  
...  
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Structural Properties ◽  
Coefficient Of Friction ◽  
Scratch Test ◽  
Lower Amount ◽  
Temperature Oxidation ◽  
Mechanical And Tribological Properties ◽  
The Coefficient Of Friction ◽  
Cr Coating

Although electroplated hard chromium coatings were extensively studied and applied in industry, the properties of the coatings after annealing at different temperatures were investigated insufficiently. In this work, the influence of heat treatment on the mechanical, tribological, and structural properties of chromium coating, electrochemically deposited on 38HN3MFA steel were investigated. A specific bath composition and deposition parameters were selected, which has been compared to the literature data. Parameter selections were based on data from military research industry and contain noticeably lower amount of sulfuric acid (1.2[Formula: see text]g/L), CrO3 (180[Formula: see text]g/L) and lower current density (25[Formula: see text]A/dm[Formula: see text]. Coefficient of friction and coatings wear rate were measured by means of ball-on-disc method at the temperature of 30[Formula: see text]C, 200[Formula: see text]C, 500[Formula: see text]C, and 700[Formula: see text]C. The coefficient of friction has decreased from 0.71 for the temperature of 30[Formula: see text]C to the value of 0.5 for 700[Formula: see text]C due to the change of wear mechanism. Hardness of the as-received coating reaches the value of 11.4[Formula: see text]GPa and 9.5, 8.3, 6.4[Formula: see text]GPa for the samples after annealing in the temperature of 200[Formula: see text]C, 500[Formula: see text]C and 700[Formula: see text]C, respectively. The influence of heat treatment on structural properties of electroplated Cr coatings was studied by X-ray diffraction. Scratch test showed that layer is characterized by excellent adhesion with no adhesive rupture. Cr-coated 38HN3MFA steel exhibits reduced susceptibility to high-temperature degradation by 25%, basing on the mass lost measured at 900[Formula: see text]C.

Effect of Directionality of Grinding Marks on Friction at Different Surface Roughness Using Inclined Scratch Test

2005 ◽  
Author(s):  
Pradeep L. Menezes ◽  
Kishore ◽  
Satish V. Kailas
Keyword(s):  
Surface Roughness ◽  
Coefficient Of Friction ◽  
Scratch Test ◽  
Layer Formation ◽  
Transfer Layer ◽  
Frictional Behavior ◽  
Mating Surface ◽  
The Coefficient Of Friction ◽  
Angle Effect ◽  
Scratch Tests

Surface topography of a tool plays an important role as it predominantly controls the frictional behavior at the interface. In the present study, Inclined Scratch Tester was used to understand the effect of directionality of surface grinding marks on coefficient of friction and transfer layer formation. EN8 steel flats were ground to attain different surface roughness with unidirectional grinding marks. Then Al-Mg alloy pins were scratched against the prepared EN8 steel flats. Grinding angle (angle between direction of scratch and grinding marks) was varied between 0° and 90° during the scratch tests. It was observed that the coefficient of friction and transfer layer formation depend primarily on the directionality of grinding marks of the harder mating surface, and independent of surface roughness of harder mating surface. The grinding angle effect on coefficient of friction was attributed to the variation of plowing component of friction with grinding angle.

ANALYSIS OF FRACTURE AND WEAR RESISTANCE OF ZrN COATINGS

Tribologia ◽  
2018 ◽  
Vol 273 (3) ◽  
pp. 39-45 ◽  
Author(s):  
Kinga CHRONOWSKA-PRZYWARA ◽  
Marcin KOT
Keyword(s):  
Wear Resistance ◽  
Coefficient Of Friction ◽  
Coating Thickness ◽  
Elasticity Modulus ◽  
Scratch Test ◽  
The Coefficient Of Friction ◽  
Steel Substrates ◽  
Resistance Tests ◽  
Ball On Disc

The article presents the results of mechanical and tribological studies of ZrN coatings that allowed the determination of their hardness, elasticity modulus, and scratch and wear resistance. Tests were carried out for 1, 1.4, and 2 μm thick ZrN coatings deposited on X5CrNi18-10 austenitic steel substrates by PVD technology. Hardness and Young's modulus of coatings, evaluated by nanoindentation, were within the 26–32 GPa, and 330–360 GPa ranges, respectively. Analysis of the adhesion of the coating to the substrate was carried out based on the results of the scratch test. The highest critical load values of LC1 and LC2 were measured for the 1.4 μm thick coating. Tribological tests performed using a ball-on-disc tribotester showed that the wear resistance increases with coating thickness. This was accompanied by a reduction of the coefficient of friction from 0.22 to 0.17.

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