scholarly journals Effect of Fe and Cr on the Macro/Micro Tribological Behaviours of Copper-Based Composites

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3417
Author(s):  
Zhongyi Zhang ◽  
Haibin Zhou ◽  
Pingping Yao ◽  
Kunyang Fan ◽  
Yongqiang Liu ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Wear Mechanism ◽  
Unit Area ◽  
Mixing Layer ◽  
Copper Matrix ◽  
Interface Layer ◽  
Mechanical Mixing ◽  
High Coefficient ◽  
Binding Interface ◽  
Friction Performance

Fe and Cr are regarded as two of the most important friction components in Cu-based composites (Cu–BCs). In this study, the microstructural detection and micro- and macro-tribology evaluation of Cu–BCs containing Fe and Cr were performed. The results indicated that both Fe and Cr formed diffusion interfaces with the copper matrix. Because of the generation of a defect interface layer, the Cr/Cu interface exhibited a low bonding strength. Owing to the excellent binding interface between Fe and Cu, the high coefficient of friction (COF) of Fe, and the formation of a mechanical mixing layer promoted by Fe, the Cu–BCs containing Fe presented better friction performance under all braking energy per unit area (BEPUA) values. The main wear mechanism of Cu–BCs containing Fe and Cr changed from abrasion to delamination with an increase in BEPUA, and the delamination of Cu–BCs containing Fe was induced by breaks in the mechanical mixed layer (MML).

Characterization of Mechanical Properties of Carbon Nanotubes in Copper-Matrix Nanocomposites

2006 ◽  
Author(s):  
Seunghyun Baik ◽  
Byeongsoo Lim ◽  
Bumjoon Kim ◽  
Untae Sim ◽  
Seyoung Oh ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Pure Copper ◽  
Copper Matrix ◽  
Mixing Process ◽  
Mechanical Mixing ◽  
Matrix Nanocomposites ◽  
Coated Carbon

Carbon nanotubes have received considerable attention because of their excellent mechanical properties. In this study, carbon nanotube - copper composites have been sintered by a mechanical mixing process. The interfacial bonding between nanotubes and the copper matrix was improved by coating nanotubes with nickel. Sintered pure copper samples were used as control materials. The displacement rate of nanotube-copper composites was found to increase at 200°C whereas that of nickel-coated nanotue-copper composites significantly decreased. The incorporation of carbon nanotubes and nickel-coated carbon nanotubes in the copper matrix decreased friction coefficients and increased the time up to the onset of scuffing compared with those of pure copper specimens.

The Study of Enhanced Mechanical Properties for Cu/Gr/2024Al Composite

2022 ◽  
Vol 905 ◽  
pp. 254-262
Author(s):  
Feng Guo Liu ◽  
Ya Nan Zhang ◽  
Hao Chen ◽  
Si Cheng Li ◽  
Ren Guo Guan
Keyword(s):  
Matrix Material ◽  
Three Dimensional ◽  
Alloy Matrix ◽  
Mixed Powder ◽  
Binding Interface ◽  
Tissue Hardness ◽  
Graphene Content ◽  
Friction Performance ◽  
Modified Graphene ◽  
The Impact

2024Al alloy powder as matrix material with nanocopper-modified graphene as reinforcement was studied to explore the effects of graphene on the tissue, hardness, friction performance of the composite. The Cu/Gr/2024Al composites were prepared via three-dimensional mixed powder and vacuum hot press sintering. The results found that the nanocopper-modified graphene could be uniformly distributed in the aluminum alloy matrix, and formed a good binding interface with the matrix material. When the graphene content was 0.75 wt.% and 1.0wt%, the impact yield strength and the hardness reached the maximum of 434.8 MPa and 118.4 HV5, which were 27.24% and 43.11% higher than that of 2024Al respectively. Furthermore, with the increase of nanocopper-modified graphene content, the corrosion resistance of composite materials in 3.5%Cl-concentration solution was improved.

Safe and Comfort Design of Micro-Structured Surfaces for Artifacts in Contact with Human

2010 ◽  
Vol 447-448 ◽  
pp. 690-694
Author(s):  
Nobuyuki Moronuki ◽  
Arata Kaneko
Keyword(s):  
Surface Structure ◽  
Coefficient Of Friction ◽  
Structural Design ◽  
Hydrodynamic Pressure ◽  
Frictional Property ◽  
Micro Structure ◽  
Sliding Speed ◽  
Structured Surfaces ◽  
High Coefficient ◽  
Wet Condition

This paper discusses a design of micro-structure on the surface in contact with human from the standpoint of frictional property and feeling. Coefficient of friction on a floor varies with sliding speed in wet environment. At some condition where hydrodynamic pressure becomes dominant, the coefficient decreases and causes slip. Experiments were carried out on a special setup and structural design to decrease this pressure was discussed. It was found that structures of sub-millimeter pitch are effective in floor design. Then, the surface structure for handles was discussed. In this case, feeling becomes important rather than the change in sliding speed condition. It was found that sub-millimeter sized structure can improve the feeling while keeping high coefficient of friction under wet condition.

Effect of contact stress on the tribology behaviors of PTFE/316L seal pairs under various abrasive-contained conditions

2020 ◽  
pp. 135065012093751
Author(s):  
Ming-xue Shen ◽  
Bo Li ◽  
De-hui Ji ◽  
Xiao-Rong He ◽  
Xiu-zhou Lin ◽  
...  
Keyword(s):  
Wear Rate ◽  
Coefficient Of Friction ◽  
Contact Stress ◽  
Wear Mechanism ◽  
Considerable Effect ◽  
Contact Stresses ◽  
The Coefficient Of Friction ◽  
Three Body ◽  
Size Threshold ◽  
Invasion Behavior

This study focuses on the tribological characteristics of polytetrafluoroethylene rubbing against 316L stainless steel in the presence of various Al2O3 abrasive particles. The ranges of the contact stresses and abrasive sizes were 2.50–5.01 MPa and 2.0–230 µm, respectively. The evolution of the coefficient of friction, abrasive invasion behavior and damage characteristics on worn surfaces, and the transformation of damage mechanisms under different contact stresses are summarized. Results demonstrate that contact stress exerts a considerable effect on abrasive invasion behavior, the coefficient of friction trends become complicated at low contact stress. With decreasing particle sizes under a contact stress of 2.50 MPa, the wear failure changes from two-body wear to three-body wear, or two wear behaviors exist simultaneously. As contact stress increases, the wear mechanism is gradually simplified. The particle size threshold that causes the change of the wear mechanism is also gradually reduced. The wear rate of polytetrafluoroethylene has no linear relationship with abrasive size, whereas wear increases with contact stress. Under 2.50 MPa conditions, the particles easily invade the tribo-interface in the friction process, thus increasing the wear rate of the metallic counterpart. In addition, with increases contact stress, the polytetrafluoroethylene material transfers to the counterface, and local adhesion occurs. When the contact stress is increased to 5.01 MPa, polytetrafluoroethylene even shows an obvious creep.

Study of Metal Friction Materials Using Hot Press

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.

Tribological properties of structural alloys for the heat exchange equipment parts subjected to fretting

2020 ◽  
pp. 401-407
Author(s):  
E.A. Marchenko ◽  
M.M. Khrushchov ◽  
S.M. Kaplunov ◽  
V.A. Panov
Keyword(s):  
Stainless Steel ◽  
Heat Exchange ◽  
Titanium Alloys ◽  
Fatigue Fracture ◽  
Coefficient Of Friction ◽  
Wear Mechanism ◽  
Sliding Friction ◽  
Adhesive Interaction ◽  
Heat Exchange Equipment ◽  
The Coefficient Of Friction

Trobological characteristics of sliding friction in stainless steel and titanium alloys in dry and water lubricated conditions have been determined. The character of the coefficient of friction variation with load and the duration of tests have confi rmed the prevailing wear mechanism in these materials to be frictional fatigue fracture that in the case of titanium alloys is accompanied with adhesive interaction and plastic plowing. The frictional fatigue curves built in a result of this investigation make possible to estimate the materials tribological longevity.

Interfacial bonding of chromium-doped copper/diamond composites fabricated by powder metallurgy method

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040050 ◽  
Author(s):  
Shanquan Jia ◽  
Yu Su ◽  
Leandro Bolzoni ◽  
Fei Yang
Keyword(s):  
Interfacial Layer ◽  
Electronic Devices ◽  
Hot Forging ◽  
Copper Matrix ◽  
Interface Layer ◽  
Interface Structure ◽  
Diamond Surface ◽  
Powder Metallurgy Method ◽  
Power Electronic ◽  
Diamond Particles

Copper/diamond composites can be used as heat-sink materials for high-power electronic devices due to their potential high thermal conductivity. However, it is challenging to obtain well-bonded interface between the copper matrix and the diamond particles. In this paper, we fabricated copper/diamond composites with [Formula: see text] wt.% of chromium additive ([Formula: see text], 3 and 7.4, and the corresponding composite was referred to as 1Cr-Cu/Dia, 3Cr-Cu/Dia and 7Cr-Cu/Dia, respectively) by hot forging of powder preforms. Results showed that only Cr3C2 interfacial layer formed between the copper matrix and the diamond particles for the 1Cr-Cu/Dia and 3Cr-Cu/Dia composites with a thickness of about 100 and 500 nm, respectively. A Cr/Cr3C2 dual layer interface formed in the 7Cr-Cu/Dia composite and its thickness was [Formula: see text]m. The coverage of diamond surface by the interface layer increased with increasing the adding amount of chromium in the composites. The 3Cr-Cu/Dia composite achieved the highest relative density and bonding strength, comparing to 1Cr-Cu/Dia and 7Cr-Cu/Dia composites, attributed to the formation of an optimal interface structure.

Investigating the effect of load on tribological behaviour of Cu composite reinforced with Ti2SnC particles

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Fangfang Zhang ◽  
Fengyun Yan ◽  
Tijun Chen ◽  
Xiaohong Li ◽  
Zhen Wang
Keyword(s):  
Mechanical Test ◽  
Electrical Contact ◽  
Mixing Layer ◽  
Tribological Behaviour ◽  
Mechanical Mixing ◽  
Content Type ◽  
Light Load ◽  
Powder Sintering ◽  
The Matrix ◽  
Sliding Electrical Contact

Purpose This paper aims to study the effect of load on the tribological behaviour of Cu-based composites, so as to obtain a suitable applied load on these composites. Design/methodology/approach Cu-based composites were prepared by powder sintering with direct current electric current heating and tested by Universal Mechanical Test-3 with a ball-on-disk at room temperature. Findings The results showed that Cu-based composites are might suitable for working under low load. There is only mild damage on the surface under a load of 2 N. While it has microcracks and shows signs of cavitation at a certain depth at 20 N and 50 N. In addition, it is evident that there are three zones in the cross-section of the matrix, namely, a mechanical mixing layer, ceramic layer and substrate, respectively. Originality/value There are two wear mechanisms at different loads, and the evolution of worn surfaces with sliding time is also involved. Thus, the developed material can be used for light load sliding electrical contact material applications.

Sign in / Sign up

Export Citation Format

Share Document