Ti3AlC2 — A Soft Ceramic Exhibiting Low Friction Coefficient

2005 ◽  
Vol 475-479 ◽  
pp. 1251-1254 ◽  
Author(s):  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Zhi Li Zhang ◽  
Shi Bo Li ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Friction Surface ◽  
High Speed ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Aluminum Carbide ◽  
Low Carbon ◽  
Friction Behavior ◽  
Sliding Speed ◽  
Al And Fe Oxides

The friction behavior of a high-purity bulk titanium aluminum carbide (Ti3AlC2) material dryly sliding against low carbon steel was investigated. Tests were performed using a block-on-disk type high-speed friction tester under sliding speed of 20 m/s and 60 m/s, several normal pressures from 0.1 to 0.8 MPa. The results showed that the friction coefficient is as low as about 0.18 for sliding speed of 20 m/s and only 0.1 for 60 m/s, and that almost not changes with the normal pressure. The reason could be related with the presence of a surface layer on the friction surface. The layer was analyzed to consist of Ti, Al and Fe oxides, which played a lubricate part inducing the friction coefficient decrease on the friction surface.

A New Ti3AlC2/Cu Cermet Exhibiting Excellent Tribological Properties

2007 ◽  
Vol 336-338 ◽  
pp. 1436-1438 ◽  
Author(s):  
Zhen Ying Huang ◽  
Hong Xiang Zhai ◽  
Ming Xing Ai
Keyword(s):  
Carbon Steel ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Behavior ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Low Carbon ◽  
Sliding Speed ◽  
Fundamental Cause ◽  
Friction Surfaces

The tribological behavior of a new cermet Ti3AlC2/Cu was experimentally investigated. The results showed that the Ti3AlC2/Cu was a good tribological material sliding against the low carbon steel, especially for a high sliding speed. The friction coefficient was as low as 0.13 ~ 0.15, and the Ti3AlC2/Cu wear rate was only 3.4×10-6 mm3/Nm, for the sliding speed of 60 m/s and the normal pressure of 0.8 MPa. The forming of a frictional film consisted of Ti, Al, Cu and Fe oxides on the friction surfaces could be a fundamental cause.

Sliding Friction Behavior of Bulk Ti3SiC2 under Difference Normal Pressures

2007 ◽  
Vol 280-283 ◽  
pp. 1353-1356 ◽  
Author(s):  
Zhen Ying Huang ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Yi Fan Wang ◽  
Zhi Li Zhang
Keyword(s):  
Friction Coefficient ◽  
Sliding Friction ◽  
Transition Period ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Low Carbon ◽  
Friction Behavior ◽  
Steady Stage ◽  
Initial Stage ◽  
Friction Surfaces

The friction behavior of Ti3SiC2 sliding against low carbon steel was studied. Tests were carried out on a block-on-disk type friction tester, with the normal pressures from 0.2 MPa to 0.8 MPa and the sliding speed of 20 m/s. The results showed that, irrespective of the normal pressure, the friction coefficient exhibits a transition period in the initial stage of a sliding friction process, in which the friction coefficient increases from an initial value and tends to a saturation value, and then enters into a relatively steady stage. The results also showed that, the friction coefficient of the steady stage decreases gradually from 0.35 to 0.26 with increase in normal pressure from 0.2 MPa to 0.8 MPa. The friction surfaces were observed by using SEM. It was found that all the surfaces were covered by a layer consisting of the frictional products with antifriction effect, and that the denseness and the thickness of the layer were increased with increase in normal pressure applied.

Frictional Layer and Its Antifriction Effect in High-Purity Ti3SiC2 and TiC-Contained Ti3SiC2

2007 ◽  
Vol 280-283 ◽  
pp. 1347-1352 ◽  
Author(s):  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Zhi Li Zhang ◽  
Yi Fan Wang
Keyword(s):  
Friction Coefficient ◽  
High Purity ◽  
Friction And Wear ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Layer By Layer ◽  
Low Carbon ◽  
Friction Surfaces ◽  
Wear Tests ◽  
Friction And Wear Tests

Characteristics of the frictional layer in high-purity Ti3SiC2 and TiC-contained Ti3SiC2, sliding against low carbon steel, were investigated. The friction and wear tests were made using a block-on-disk type friction tester with sliding speed of 20 m/s and several normal pressures from 0.1 MPa to 0.8 MPa. It was found that all friction surfaces, whether high-purity Ti3SiC2 or TiC-contained Ti3SiC2, were covered by a layer consisting of the oxides of Ti, Si and Fe. The layer was sticky, superimposed layer-by-layer, and the compact was increased with the normal pressure increasing. Because its antifriction effect, the friction coefficient decreases from the maximum 0.35 to 0.27 with increase in the normal pressure from 0.2 MPa to 0.8 MPa for the high-purity Ti3SiC2, and decreases from the maximum 0.55 to 0.37 for the same change of the normal pressure for the TiC-contained Ti3SiC2. The contained TiC grains had effects on the stickiness, liquidness, as well as the morphology of the layer, and induced the friction coefficient to increase in the entire level.

Wear Characteristics of Bulk Ti3AlC2 under Current-Carrying Conditions

2007 ◽  
Vol 561-565 ◽  
pp. 563-566
Author(s):  
Zhen Ying Huang ◽  
Hong Xiang Zhai ◽  
Hua Zhang ◽  
Hong Bing Zhang
Keyword(s):  
Wear Rate ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Mechanical Effect ◽  
Low Carbon ◽  
Wear Properties ◽  
Sliding Speed ◽  
Wear Characteristics ◽  
Friction Tester ◽  
Iron Titanate

The current-carrying wear characteristics of Ti3AlC2 sliding against low-carbon steel were investigated. Tests were carried out using a block-on-disk type friction tester, with sliding speeds of 20~60 m/s, normal pressures range in 0.4~ 0.8 MPa, and the current intensity of 0 A, 50 A and 100 A. The Ti3AlC2 showed good current-carrying wear properties. At the sliding speed of 20 m/s, the wear rate of the Ti3AlC2 (× 10-6 mm3/Nm) was varied in the range of (2.05 ~ 2.41), (2.64 ~ 2.39) and (6.26 ~ 3.62), under the current of 0 A, 50 A and 100 A, respectively. Both the surfaces of Ti3AlC2 and the steel were covered by a frictional film, which was consisted of iron titanate (Fe2.25Ti0.75O4) and aluminum iron oxide (AlFeO3). The wear rate of Ti3AlC2 with current was composed of two parts: the interaction of micro-arc ablation and mechanical friction, and the coupled action of thermal and mechanical effect. Which one will be the main mechanism depends on the material parameters of Ti3AlC2 and the mechanical parameters such as the normal pressure or the sliding speed.

Self-Lubricant Effect of Tri-Oxidizing Layer in Surface of Bulk Ti3SiC2 Materials

2005 ◽  
Vol 475-479 ◽  
pp. 1259-1262 ◽  
Author(s):  
Zhi Li Zhang ◽  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Yang Zhou ◽  
Shi Bo Li
Keyword(s):  
Friction Coefficient ◽  
Oxidation Reaction ◽  
Sliding Friction ◽  
Low Carbon Steel ◽  
Chemical Oxidation ◽  
Primary Reason ◽  
Low Carbon ◽  
Sliding Speed ◽  
Friction Tester ◽  
Worn Surface

In this paper, tribological tests for Ti3SiC2 sliding against low carbon steel were made on a block-on-disc type friction tester, with the normal pressures from 0.1 to 0.8 MPa and the sliding speed of 30 to 50 m/s. The surface state was observed and analyzed by SEM and XRD. A definite tribo-glazing layer was found over the worn surface of the Ti3SiC2 block, which seems to be primary reason for Ti3SiC2 to have comparatively lower friction coefficient and wear rate, because the tribo-glazing layer would be fusible under high frictional temperature. The tribo-glazing layer was the results of tribo-chemical oxidation reaction and the cause forming it could be the high frictional temperature and the mechanical catabolism in the surface of Ti3SiC2 during sliding friction. Due to the tribo-oxidation reaction is un-reversible and self-adaptive, the tribo-glazing layer in area and thickness are function of normal pressures and sliding speed.

Numerical Investigation of Size Effect on Dry Friction Behavior in Micro Upsetting Process

2014 ◽  
Vol 997 ◽  
pp. 321-324
Author(s):  
Wei Zheng ◽  
Guang Chun Wang ◽  
Bing Tao Tang ◽  
Xiao Juan Lin ◽  
Yan Zhi Sun
Keyword(s):  
Friction Coefficient ◽  
Size Effect ◽  
Dry Friction ◽  
Normal Pressure ◽  
Friction Model ◽  
Strain Hardening Exponent ◽  
Forming Process ◽  
Friction Behavior ◽  
Initial Yield Stress ◽  
Coulomb’S Friction

After modifying the Wahime/Bay friction model, a new friction model suitable for micro-forming process without lubrication is established. In this model, it is shows that the friction coefficient is a function of strain hardening exponent, the normal pressure and the initial yield stress of material. Based on the experimental data, the micro-upsetting process is simulated using the proposed friction model. The simulation results are used to investigate the size effect on the dry friction behavior. It is found that the Coulomb’s friction coefficient is dropping with miniaturization of specimens when the amount of reduction is not too large.

scholarly journals Temperature Measurement by Visible Pyrometry: Orthogonal Cutting Application

2004 ◽  
Vol 126 (6) ◽  
pp. 931-936 ◽  
Author(s):  
N. Ranc ◽  
V. Pina ◽  
G. Sutter ◽  
S. Philippon
Keyword(s):  
High Speed ◽  
Orthogonal Cutting ◽  
Broad Band ◽  
Cutting Speed ◽  
Low Carbon Steel ◽  
Ccd Camera ◽  
Maximum Temperature ◽  
Low Carbon ◽  
Observation Area ◽  
Good Spatial Resolution

The working processes of metallic materials at high strain rate like forging, stamping and machining often induce high temperatures that are difficult to quantify precisely. In this work we, developed a high-speed broad band visible pyrometer using an intensified CCD camera (spectral range: 0.4 μm–0.9 μm). The advantage of the visible pyrometry technique is to limit the temperature error due to the uncertainties on the emissivity value and to have a good spatial resolution (3.6 μm) and a large observation area. This pyrometer was validated in the case of high speed machining and more precisely in the orthogonal cutting of a low carbon steel XC18. The cutting speed varies between 22 ms−1 and 60 ms−1. The experimental device allows one to visualize the evolution of the temperature field in the chip according to the cutting speed. The maximum temperature in the chip can reach 730°C and minimal temperature which can be detected is around 550°C.

Tribo-Chemical Reaction in Bulk Ti3SiC2 under Sliding Friction

2007 ◽  
Vol 280-283 ◽  
pp. 1357-1360 ◽  
Author(s):  
Zhi Li Zhang ◽  
Hong Xiang Zhai ◽  
Zhen Ying Huang ◽  
Cui Wei Li ◽  
Yi Fan Wang ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Sliding Friction ◽  
Low Carbon Steel ◽  
Normal Pressure ◽  
Second Phase ◽  
Low Carbon ◽  
X Ray Diffraction ◽  
Energy Dispersion Spectroscopy ◽  
Chemical Reaction Mechanism ◽  
Xrd Patterns

The Ti3SiC2 samples with a second phase TiC, prepared by hot-pressing progress route, were rubbed against low carbon steel disk with a sliding speed of 20 m/s under normal pressure 0.8 Mpa in atmosphere on a block-on-disk type friction tester. The morphology was observed by scanning electron microscope (SEM) and meanwhile the composition was checked by energy dispersion spectroscopy (EDS). X-ray diffraction (XRD) patterns show some impurity phases containing Ti, Si and Fe oxides in the samples. The possible tribo-chemical reaction mechanism on surface layer of Ti3SiC2 was suggested.

Experimental Investigation of Prototype Water-Lubricated Compliant Foil Bearings

2011 ◽  
Vol 490 ◽  
pp. 97-105 ◽  
Author(s):  
Artur Olszewski ◽  
Michał Wodtke ◽  
Piotr Hryniewicz
Keyword(s):  
Experimental Investigation ◽  
Friction Coefficient ◽  
Gas Turbines ◽  
High Speed ◽  
Journal Bearings ◽  
Radial Load ◽  
Sliding Speed ◽  
Good Tolerance ◽  
Foil Bearings ◽  
Water Pumps

First gas-lubricated compliant foil bearings (CFBs) were built in the 1950s. Due to their significant advantages, such as oil-free operation, good tolerance to bearing misalignment and very low maintenance, they have been penetrating the bearing applications for high speed compressors, air-cycle machines and gas turbines. The work presented here investigates a novel idea of water-lubricated compliant foil bearings, which could be used in applications where environmentally friendly lubrication is desired, for example in hydroelectric turbines or water pumps. Experimental results collected for three prototype water-lubricated foil journal bearings are presented. The tests were conducted under steady radial load and with the sliding speed varied incrementally. A sequence of design improvements is presented, with the best bearing demonstrating friction coefficient of about 0.01 at the sliding speed of about 4 m/s and the radial load of about 300 kPa. Encountered difficulties, research methodology and the testing equipment are also described.

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