The Influence of Mass Fraction and Size of Glassy Carbon Particles on the Tribological Properties of Metal – Ceramic Composites

2016 ◽  
Vol 246 ◽  
pp. 157-162
Author(s):  
Bartosz Hekner ◽  
Jerzy Myalski ◽  
Paweł Krzywda ◽  
Aleksandra Miczek
Keyword(s):  
Tribological Properties ◽  
Glassy Carbon ◽  
Mass Fraction ◽  
High Energy ◽  
Ceramic Composites ◽  
Milling Process ◽  
Carbon Particles ◽  
Tribological Application ◽  
Metal Ceramic ◽  
Properties Of Materials

This paper presents the manufacturing process and the results of measurements for aluminum – aluminum oxide materials with addition of glassy carbon particles (GC). The composites were manufactured via high energy milling process with hot pressing subsequently. The influence of mass fraction (5, 10 and 15 wt.%) and a size of GC particles (<40, 40-80, 80-120, 120-160, 160-200µm) on the microstructure and properties were analysed. The complex meaning of GC particles for all, milling process, microstructure and final properties were discovered. After based description of materials, the tribological measurement were performed under two loads – 35 and 50N. It was noted, that mass fraction of GC particles have influence on tribological properties of materials. The composite with 5 wt.% revealed the best friction properties without any significant differences between analysed loads. The influence of particles size proved that the most effective fraction for tribological application is 120 – 160µm.

The influence of carbon additions on structure and properties of composites manufactured via powder metallurgy method

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000125-000130
Author(s):  
Bartosz Hekner ◽  
Jerzy Myalski
Keyword(s):  
Carbon Nanotubes ◽  
Silicon Nitride ◽  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Glassy Carbon ◽  
High Energy ◽  
Powder Metallurgy Method ◽  
Composite Powders ◽  
Carbon Particles ◽  
Carbon Additions

This paper presents an influence of reinforcement and additions types on tribological properties for composite materials produced for potential application in high loaded friction point. The influence of carbon nanotubes or amorphous form of carbon on tribological properties was subject of authors' interest. A technology of materials manufacturing based on preparation of composite powders using high energy ball milling, with subsequent hot pressing in the semi-liquid phase. All materials based on an aluminum alloys, with silicon carbide (SiC) or silicon nitride particles (Si3N4) applied as a reinforcement. As a additions 1 wt.% of multiwalled carbon nanotubes (CNT) or 5 wt.% of glassy carbon particles (GCp) were used. A proper parameters selection (speed, powder to ball ratio, time ect.) of high energy milling led to fragmentation of ceramic particles up to nano- or submicro scale with desirable homogenization in whole volume of solid material. Due to partially crushed of glassy carbon particles, their size was between 2 – 200 μm. However GCp revealed also proper distribution in volume of composite. Moreover, the good quality of bonding between matrix and reinforcement particles were achieved due to high energy during milling. For manufactured materials a rating of tribological properties (coefficient of friction, wear rate, ect.) at ambient and high temperature were made. The research confirmed that, due to desirable coefficient of friction (COF) value and low mass loss, manufactured materials can be applied in automotive industry, eg. for brake pads. A high stability of COF on desirable value (0.5 – 0.8) was observed up to temperature higher than 500 °C. The application of carbon additions resulted in increasing of friction properties. The material with silicon nitride as a reinforcement and glassy carbon particles addition revealed the best friction properties between analysed materials.

THE INFLUENCE OF GLASSY CARBON AND ITS FORMS ON TRIBOLOGICAL PROPERTIES OF ALUMINIUM MATRIX COMPOSITES

Tribologia ◽  
2019 ◽  
Vol 285 (3) ◽  
pp. 79-87 ◽  
Author(s):  
Jerzy MYALSKI ◽  
Andrzej Posmyk ◽  
Bartosz HEKNER ◽  
Marcin GODZIERZ
Keyword(s):  
Coefficient Of Friction ◽  
Tribological Properties ◽  
Glassy Carbon ◽  
Amorphous Structure ◽  
Matrix Composites ◽  
Alloy Matrix ◽  
Entire Volume ◽  
Carbon Particles ◽  
The Matrix ◽  
The Coefficient Of Friction

Carbon with an amorphous structure was used as a component to modify the tribological properties of engineering plastics. Its construction allows the formation of carbon-based wear products during friction, adhesively bonded to the surface of cooperating machine parts, acting as a solid lubricant. The work compares the tribological properties of two groups of composites with an aluminium alloy matrix in which glassy carbon appeared in the form of particles and an open cell foam fulfilling the role of strengthening the matrix. The use of spatial structures of reinforcement provides, in comparison with the strengthening of particles, homogeneity of carbon distribution in the entire volume of the composite. The tests carried out on a pin-disc tester showed that the use of spatial carbon structures in the composite ensures a greater coefficient of friction stability than when reinforcing with particles, and the coefficient of friction with a small proportion of carbon foams (about 1 wt%) is comparable with the coefficient of friction in the contact with composites containing 5-10% carbon particles in granular form.

Evaluation of Tribological Properties of Organoclay Reinforced UHMWPE Nanocomposites

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Abdul Samad Mohammed ◽  
Annas bin Ali ◽  
Merah Nesar
Keyword(s):  
Tribological Properties ◽  
Large Scale ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
High Energy ◽  
Milling Process ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Uniform Dispersion ◽  
Ultrahigh Molecular Weight ◽  
Energy Ball

The current study is aimed to investigate the tribological properties of ultrahigh molecular weight polyethylene (UHMWPE) reinforced with organoclay Cloisite (C15A). Nanocomposites are prepared using a high energy ball milling process followed by hot pressing. Three different loadings of 0.5 wt.%, 1.5 wt.%, and 3 wt.% of C15A, respectively, are used as reinforcement. Results from the ball-on-disk wear tests showed that nanocomposites reinforced with 1.5 wt.% of C15A exhibited best wear resistance and lower coefficient of friction (COF), with C15A reducing the wear rate by 41% and the COF by 38%, when compared to the pristine UHMWPE. These improvements are attributed to the uniform dispersion of the nanosized clay platelets preventing large-scale material removal and formation of a thin tenacious, continuous transfer film on the counterface for C15A organoclay composites. X-ray diffraction (XRD), scanning electron microscopy (SEM), and optical profilometry are used to characterize the morphology of the nanocomposites and the wear tracks. SEM images of worn surfaces indicated more abrasive wear for the case of pristine UHMWPE as compared to organoclay composites.

Microstructure and Tribological Properties of the Copper Matrix Composite Materials Containing Lubricating Phase Particles

2014 ◽  
Vol 59 (1) ◽  
pp. 365-369 ◽  
Author(s):  
B. Juszczyk ◽  
J. Kulasa ◽  
W. Malec ◽  
Sz. Malara ◽  
M. Czepelak ◽  
...  
Keyword(s):  
Composite Materials ◽  
Powder Metallurgy ◽  
Tribological Properties ◽  
Glassy Carbon ◽  
Copper Alloys ◽  
Metallic Matrix ◽  
Copper Matrix ◽  
Stir Casting ◽  
Mechanical Stirring ◽  
Carbon Particles

Abstract The paper presents results of the studies into influence of individual particles of lubricating phase on microstructure and tribological properties of copper based composite materials for slide bearings. The studied material was composed of copper alloys with lubricating phase particles, e.g. in a form of graphite and glassy carbon. The metallic matrix of composite materials consisted of Cu-Sn type alloys. Production of the examined materials included processes with complete or partial participation of liquid phase and was conducted in two ways. In production of composites both classical powder metallurgy technology was applied and a method of melting with simultaneous mechanical stirring in liquid state (stir casting). Particles of lubricating phases were heated up to the temperature of 200°C and introduced into a liquid metal and then stirring process at constant rate of 1500 rpm rotational speed was applied. To improve wettability of graphite and glassy carbon particles titanium was introduced into the metallic matrix. In production of the composites by powder metallurgy methods the process consisted of mixing of bronze powders and particles of non-metallic phases and then their consolidation. Both quantitative and qualitative structure analysis of the produced composites was performed. Also through evaluation of tribological properties (friction coefficient, wear) with CSM Instruments high temperature tribometer THT was conducted.

Residual stresses in novel metal/ceramic composites exhibiting a lamellar microstructure

2009 ◽  
Vol 24 (S1) ◽  
pp. S59-S64 ◽  
Author(s):  
Siddhartha Roy ◽  
Jens Gibmeier ◽  
Alexander Wanner
Keyword(s):  
Residual Stresses ◽  
Porous Ceramic ◽  
Lamellar Microstructure ◽  
Cost Effective ◽  
High Energy ◽  
Ceramic Composites ◽  
Aluminum Silicon Alloy ◽  
Spatially Resolved ◽  
Production Route ◽  
Metal Ceramic

The aim of this study is to analyze the mechanics of a new class of metal/ceramic composites on a mesoscopic length scale. These composites are produced by melt infiltration of porous ceramic preforms produced by freeze casting and subsequent sintering. This production route has a high application potential since it offers a cost-effective way to obtain composites with ceramic content in the 30 to 70 vol.%range. The as-produced material exhibits a hierarchical domain structure with each domain composed of alternating layers of metallic and ceramic lamellae. Residual stresses present in all phases of the composite produced by infiltrating alumina preforms with a eutectic aluminum-silicon alloy have been measured. Integral as well as spatially resolved measurements were carried out on single-domain samples at the high-energy, energy-dispersive diffraction (EDDI) beamline at the synchrotron radiation source BESSY (Berlin, Germany). Results show that strongly fluctuating residual stresses are introduced by the production process, which can be rationalized by taking into account the thermal expansion mismatch of alloy and preform.

The influence of glassy carbon on tribological properties in metal – ceramic composites with skeleton reinforcement

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000121-000124 ◽  
Author(s):  
Jerzy Myalski ◽  
Bartosz Hekner ◽  
Andrzej Posmyk
Keyword(s):  
Mechanical Properties ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Glassy Carbon ◽  
Porous Ceramic ◽  
Carbon Foam ◽  
Ceramic Composites ◽  
Carbon Layer ◽  
Ceramic Foam ◽  
Skeleton Structure

This paper presents a results of mechanical and tribological properties of aluminum based composites with skeleton reinforcement. The aluminum alloy based composites were produced using pressure infiltration process. As a reinforcement ceramic foam with opened cells was applied. This reinforcement structure give an opportunity to limit the most common defects (like agglomeration, inhomogeneity, ect.) occurring in composite materials obtained by casting. In presented research three different types of porous foam were analysed. There were alumina foam covered by thin glassy carbon layer (Al2O3 – GC) and two types of glassy carbon foams (GC). Due to application of porous ceramic foam, an increasing of composite mechanical properties are expected. An additional glassy carbon layer with thickness up to 5 μm was applied for increasing a thermal conductivity and rapid heat dissipation from the material. Moreover, the skeleton structure of glassy carbon, and its wear mechanism, should decrease a friction coefficient value. Two manufactured types of composites: Al2O3 – GC foam and own produced glassy carbon foam were compared with material reinforced by spatial carbon structure obtained from commercial RVC (produced by Reynolds) foam. The results showed that the application of porous ceramic and ceramic – carbon reinforcement skeletons led to increasing of mechanical properties of composite. The conducted research using pin–on–disc method, with 2,5 MPa of load and 1,0 m/s of speed revealed that glassy carbon have significant influence on decreasing friction coefficient and wear rate. An analysis of material external layer in areas after coupling with pin (wear track) indicated a fragmentation of glassy carbon foam. The wear products are not remove from friction surfaces, but these products create thin carbon film with lubricant properties. The conducted research showed both, a possibility to produce composites with skeleton structure of reinforcement and a possibility of correction of material tribological properties using glassy carbon.

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