Scratch Resistance of the Si3N4-Graphene Nanoplatelets Composites

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.

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Tribological Aspects, Optimization and Analysis of Cu-B-CrC Composites Fabricated by Powder Metallurgy

Materials ◽

10.3390/ma14154217 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4217

Author(s):

Üsame Ali Usca ◽

Mahir Uzun ◽

Mustafa Kuntoğlu ◽

Serhat Şap ◽

Khaled Giasin ◽

...

Keyword(s):

Weight Loss ◽

Wear Rate ◽

Coefficient Of Friction ◽

Applied Load ◽

Practical Significance ◽

Tribological Characteristics ◽

M 10 ◽

Wide Range ◽

The Coefficient Of Friction ◽

Four Levels

Tribological properties of engineering components are a key issue due to their effect on the operational performance factors such as wear, surface characteristics, service life and in situ behavior. Thus, for better component quality, process parameters have major importance, especially for metal matrix composites (MMCs), which are a special class of materials used in a wide range of engineering applications including but not limited to structural, automotive and aeronautics. This paper deals with the tribological behavior of Cu-B-CrC composites (Cu-main matrix, B-CrC-reinforcement by 0, 2.5, 5 and 7.5 wt.%). The tribological characteristics investigated in this study are the coefficient of friction, wear rate and weight loss. For this purpose, four levels of sliding distance (1000, 1500, 2000 and 2500 m) and four levels of applied load (10, 15, 20 and 25 N) were used. In addition, two levels of sliding velocity (1 and 1.5 m/s), two levels of sintering time (1 and 2 h) and two sintering temperatures (1000 and 1050 °C) were used. Taguchi’s L16 orthogonal array was used to statistically analyze the aforementioned input parameters and to determine their best levels which give the desired values for the analyzed tribological characteristics. The results were analyzed by statistical analysis, optimization and 3D surface plots. Accordingly, it was determined that the most effective factor for wear rate, weight loss and friction coefficients is the contribution rate. According to signal-to-noise ratios, optimum solutions can be sorted as: the highest levels of parameters except for applied load and reinforcement ratio (2500 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 0 wt.%) for wear rate, certain levels of all parameters (1000 m, 10 N, 1.5 m/s, 2 h, 1050 °C and 2.5 wt.%) for weight loss and 1000 m, 15 N, 1 m/s, 1 h, 1000 °C and 0 wt.% for the coefficient of friction. The comprehensive analysis of findings has practical significance and provides valuable information for a composite material from the production phase to the actual working conditions.

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The effects of applied load on the coefficient of friction in Cu-MMC brake pad/Al-SiCp MMC brake disc system

Wear ◽

10.1016/j.wear.2010.09.001 ◽

2010 ◽

Vol 270 (1-2) ◽

pp. 73-82 ◽

Cited By ~ 62

Author(s):

D. Gultekin ◽

M. Uysal ◽

S. Aslan ◽

M. Alaf ◽

M.O. Guler ◽

...

Keyword(s):

Coefficient Of Friction ◽

Applied Load ◽

Brake Disc ◽

Brake Pad ◽

The Coefficient Of Friction

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Preparation and Thermal Fatigue Behaviors of Silicon Nitride Nano-Ceramics

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1095.48 ◽

2015 ◽

Vol 1095 ◽

pp. 48-52

Author(s):

Chun Yan Tian ◽

Hai Jiang

Keyword(s):

Mechanical Properties ◽

Silicon Nitride ◽

Thermal Fatigue ◽

Fatigue Properties ◽

Hot Press ◽

Thermal Fatigue Resistance ◽

Amorphous Si ◽

Hot Press Sintering ◽

Spherical Grains ◽

Sintered Materials

Silicon nitride nanoceramics were prepared by hot press sintering amorphous Si3N4and α-Si3N4nanopowders. The microstructures as well as the effect of starting powders size on the mechanical properties and thermal fatigue properties were investigated. The results show that microstructure of sintered materials consists of spherical grains with approximate size of 100 nm. The mechanical properties and thermal fatigue resistance vary with the addition of α–Si3N4powders. The maximum flexural strength and fracture toughness are obtained when the α–Si3N4powders amount is 40wt.%. And the Si3N4nanoceramic added 40wt.% α–Si3N4powders has the best capability to suppress crack propagation and the highest critical temperature difference.

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Sintering of β-Si3N4 Powder Prepared by Self-Propagating High-Temperature Synthesis (SHS)

Materials Science Forum ◽

10.4028/www.scientific.net/msf.546-549.2179 ◽

2007 ◽

Vol 546-549 ◽

pp. 2179-2182 ◽

Cited By ~ 2

Author(s):

Ling Bai ◽

Xing Yu Zhao ◽

Chang Chun Ge

Keyword(s):

High Temperature ◽

Silicon Nitride ◽

Bending Strength ◽

Sintering Process ◽

Hot Press ◽

Temperature Synthesis ◽

High Temperature Synthesis ◽

Good Sinter ◽

The Cost ◽

Hot Press Sintering

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.

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Influence of Additives and Hot-Press Sintering on Mechanical and Lipophilic Properties of Silicon Nitride Ceramics

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.46.2041 ◽

2005 ◽

Vol 46 (9) ◽

pp. 2041-2046 ◽

Cited By ~ 2

Author(s):

Mitsuo Kido ◽

Tarou Tokuda ◽

Rongguang Wang ◽

Fumihiro Suzumura

Keyword(s):

Silicon Nitride ◽

Hot Press ◽

Nitride Ceramics ◽

Hot Press Sintering

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Influence of Additives and Hot-Press Sintering on Lipophilic Properties of Silicon Nitride Ceramics

Materials Science Forum ◽

10.4028/www.scientific.net/msf.539-543.2687 ◽

2007 ◽

Vol 539-543 ◽

pp. 2687-2692

Author(s):

Tarou Tokuda ◽

Mitsuo Kido ◽

Rong Guang Wang ◽

Gonojo Katayama ◽

Fumihiro Suzumura

Keyword(s):

Silicon Nitride ◽

Hot Press ◽

Nitride Ceramics ◽

Hot Press Sintering

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Effect of Starting Powders on Microstructure and Properties of Silicon Nitride Nanoceramics

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.217-219.239 ◽

2012 ◽

Vol 217-219 ◽

pp. 239-244

Author(s):

Hai Jiang ◽

Chun Yan Tian

Keyword(s):

Mechanical Properties ◽

Silicon Nitride ◽

Thermal Shock ◽

Thermal Shock Resistance ◽

Grain Morphology ◽

Hot Press ◽

Shock Resistance ◽

Hot Press Sintering ◽

Spherical Grains ◽

Hardness Values

Silicon nitride nanoceramics were fabricated by hot press sintering two kinds of Si3N4nano-sized powders. The effect of starting powders on microstructure, mechanical properties and thermal shock resistance were investigated. The microstructure of sintered materials consists of spherical grains and the addition of α–Si3N4to starting powders does not affect the grain morphology. The flexural strength, fracture toughness and thermal shock resistance increase with the increase in amount of α–Si3N4starting powders, and the maximum mechanical properties are obtained when the amount of α–Si3N4 powders is 40wt.%. The hardness values decrease with the increase of α–Si3N4amount.

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Study of Metal Friction Materials Using Hot Press

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.750-752.2084 ◽

2013 ◽

Vol 750-752 ◽

pp. 2084-2087

Author(s):

Shenq Yih Luo ◽

Can Yu Bai

Keyword(s):

Coefficient Of Friction ◽

Wear Mechanisms ◽

Bending Strength ◽

Copper Matrix ◽

Friction Material ◽

The Other ◽

Hot Press ◽

Friction Materials ◽

The Coefficient Of Friction ◽

Metal Friction

The metal friction materials of copper matrix with and without resin using hot press were investigated to study their hardness, porosities, bending strengths, microstructures, coefficient of frictions, and wear mechanisms. The experiment results show that the hardness and bending strength of the friction materials with increase of amount of copper increase, but the porosity decreases. The resulting coefficient of frictions show more stable and their values are about 0.5~0.6. In addition, the wear mechanism of friction material shows mainly grit abrasive and adhesion, which cause the coefficient of friction to become stable. On the other hand, when the copper matrix containing resin is used, the resulting porosity of friction materials becomes higher and the bending strength decreases. This shows that the wear mechanisms of grit abrasive, roughness, and adhesion cause the coefficient of friction to produce a higher value.

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Friction of a Rubber Wedge Sliding on Glass

Rubber Chemistry and Technology ◽

10.5254/1.3538536 ◽

1991 ◽

Vol 64 (1) ◽

pp. 108-117 ◽

Cited By ~ 6

Author(s):

C. W. Extrand ◽

A. N. Gent ◽

S. Y. Kaang

Keyword(s):

Coefficient Of Friction ◽

Applied Load ◽

Unit Length ◽

Sliding Speed ◽

Normal Loading ◽

Contact Width ◽

Wide Range ◽

The Coefficient Of Friction ◽

Apparent Coefficient Of Friction ◽

Pressure Independent

Abstract The contact width, and hence contact area, for an elastic wedge pressed against a rigid flat surface appears to be proportional to the applied load per unit length. For a particular rubber sample, the reciprocal of the constant of proportionality, i.e., the mean normal pressure, was 130 kPa, i.e., about 7% of the tensile modulus E of the material. It was also independent of sliding speed over the range examined. Thus, a sharp wedge gave a relatively high loading pressure, independent of the applied load. As a result, the coefficient of friction was also independent of applied load over a wide range. The coefficient of friction was measured for a wedge of an unfilled natural rubber vulcanizate over wide ranges of sliding speed (50 µm/s to 100 mm/s) and test temperature (3°C to 63°C). It was found to increase with sliding speed and decrease with temperature over these ranges. The results at different temperatures were superposable using the WLF rate-temperature equivalence to create a master curve of friction vs. reduced sliding speed, rising from a value of about 1.5 at high temperatures and low speeds to about 5 at low temperatures and high speeds. Chlorination of a thin surface region reduced the coefficient of friction and its dependence on speed and temperature. It then became similar to that typically found for thermoplastics, 0.4 to 0.7. The geometry of sliding a flexible strip against a rigid curved surface caused high values of the apparent coefficient of friction to be obtained at relatively small departures from normal loading. In an extreme case, frictional seizure was observed when a high-friction sample contacted the glass surface at an angle of about 15° to the direction of loading. The apparent coefficient of friction then became indefinitely large. This same phenomenon of abnormally large frictional effects would be expected to occur in the case of conventional windshield-wiper blades, sliding over curved glass windshields.

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