Glassy carbon particles as component to modification of tribological properties

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.

Download Full-text

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

Additional Conferences (Device Packaging HiTEC HiTEN & CICMT) ◽

10.4071/cicmt-tp45 ◽

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.

Download Full-text

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

Archives of Metallurgy and Materials ◽

10.2478/amm-2014-0061 ◽

2014 ◽

Vol 59 (1) ◽

pp. 365-369 ◽

Cited By ~ 3

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.

Download Full-text

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.246.157 ◽

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.

Download Full-text

TRIBOLOGICAL PROPERTIES OF SILICON INFILTRATED SiC GRADES CONTAINING CARBON PARTICLES

Le Journal de Physique Colloques ◽

10.1051/jphyscol:19861113 ◽

1986 ◽

Vol 47 (C1) ◽

pp. C1-745-C1-749

Author(s):

W. HEIDER ◽

R. RÖTTENBACHER

Keyword(s):

Tribological Properties ◽

Carbon Particles

Download Full-text

Tribological Characteristics of the Magnesium Matrix-Glassy Carbon Particles Composite Manufactured by Different Casting Methods

Conference Papers in Science ◽

10.1155/2015/919308 ◽

2015 ◽

Vol 2015 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Anita Olszówka-Myalska ◽

Jerzy Myalski ◽

Bartosz Hekner

Keyword(s):

Glassy Carbon ◽

Sliding Friction ◽

Particulate Composite ◽

Magnesium Matrix ◽

Cast Material ◽

Carbon Particles ◽

Die Cast ◽

Pin On Disc ◽

Worn Surface ◽

Gravity Cast

A particulate composite with a magnesium matrix (Mg3Al) and glassy carbon particles (GCp) obtained under industrial conditions from a gravity cast and pressure die cast suspension was examined. The influence of the casting procedure on the microstructure and mechanical properties was revealed. Sliding friction tests by the pin-on-disc method for different loads (2.3, 5, and 9.3 N) and speeds (0.06, 0.09, and 0.14 m/s) were performed. Regardless of the technology, the sliding friction coefficient’s value strongly depended on the load and speed. Its value was changing (0.35–0.13) and was usually higher for the pressure die cast material, yet the wear resistance of the composite processed in that way was considerably better compared with the gravity cast. The results of the worn surface observation by SEM with EDS showed an influence of the initial Mg3Al-GCp composite’s microstructure on the processes of its wear.

Download Full-text

Study of Interaction between Liquid Magnesium Alloy and Glassy Carbon Particles

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.227.178 ◽

2015 ◽

Vol 227 ◽

pp. 178-181

Author(s):

Anita Olszówka-Myalska ◽

Jacek Chrapoński

Keyword(s):

Magnesium Alloy ◽

Glassy Carbon ◽

Die Casting ◽

Mechanical Mixing ◽

Carbon Particles ◽

Type Layer ◽

Thin Oxide ◽

Pressure Die Casting

In the presented experiments, the influence of a liquid magnesium alloy with Zr and RE reinforced on glassy carbon particles (GCp) in composites obtained by the mechanical mixing of a suspension, its pressureless solidification and by pressure die casting was examined. The microstructure of the as-received GCp and after their isolation from the composite was characterized by SEM and EDS methods. The presence of a thin oxide type layer with a high RE content was found, independent of the applied composite technology.

Download Full-text

An Optical Fiber Sensor for Measuring Light Absorption in Suspension Solutions

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.121-126.2509 ◽

2011 ◽

Vol 121-126 ◽

pp. 2509-2513

Author(s):

Fei Bing Xiong ◽

N Djeu ◽

Wen Zhang Zhu

Keyword(s):

Optical Fiber ◽

Glassy Carbon ◽

Fiber Optic ◽

Optical Fiber Sensor ◽

Fiber Optic Sensor ◽

Fiber Sensor ◽

Graphite Flake ◽

Chemical Information ◽

Carbon Particles ◽

Optic Sensor

An optical fiber sensor based on attenuated total reflectance (ATR) for extraction chemical information from highly scattering turbid materials has been evaluated. The influence of particles on bulk absorption and ATR transmitted spectra of micron-sized graphite flakes and spherical glassy carbon suspensions were investigated. The ATR transmitted spectra of coiled fiber-optic sensor in those suspensions with various concentrations are insensitive to scattering of suspended particles, especially for graphite flake suspensions. The reason for different influence of graphite flakes and spherical glassy carbon particles suspensions on e ATR spectra analyzed. This study demonstrates that fiber-optic sensor based on ATR technique is a feasible technique in application for monitoring turbid suspensions.

Download Full-text