Structure and Worn Surface Morphology on Copper Containing Composites under Dry Sliding with High Contact Current Density

2016 ◽  
Vol 712 ◽  
pp. 137-142
Author(s):  
Viktor V. Fadin ◽  
Marina I. Aleutdinova ◽  
Valery E. Rubtsov ◽  
Valeriya A. Aleutdinova
Keyword(s):  
Surface Layer ◽  
Liquid Phase ◽  
Surface Morphology ◽  
Current Density ◽  
Wear Intensity ◽  
Dry Sliding ◽  
Sliding Surface ◽  
Worn Surface

Dry sliding of the sintered composites of compositions Cu-graphite-Fe and Cu-Fe against steel at the contact current density higher 100 A/cm2 has been carried out. The presence of FeO oxide in surface layer was shown. The low content of FeO oxide resulted in high wear intensity. Formation of a liquid phase on a sliding surface was observed. Wear intensity was low in the presence of a liquid phase on the worn surface.

scholarly journals CHARACTERISTICS OF DRY SLIDING ELECTRIC CONTACT OF METALS IN CONDITIONS OF CATASTROPHIC WEARING

2019 ◽  
Vol 62 (2) ◽  
pp. 103-108 ◽  
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin
Keyword(s):  
Current Density ◽  
Niti Alloy ◽  
Wear Intensity ◽  
Contact Temperature ◽  
Structural Defects ◽  
Dry Sliding ◽  
Sliding Surface ◽  
Surface Layers ◽  
Strong Adhesion ◽  
Steel 1020

The authors have studied the relation between wear intensity, average contact temperature and phase composition of the surface layers ofAISI 1020 steel, copper and NiTi alloy in dry sliding against the steel counterbody under electric current of density higher than 100  A/cm2 . These contact characteristics are considered carefully at the beginning of catastrophic wear, when the surface layers transit to the utmost state. It was noted that relaxation of stresses in the surface layers was due to the structural transformation in normal wear regime. It leads to tribolayers formation. The high strength of the copper tribolayer is first of all due to the formation of FeO oxide on the sliding surface, which prevents adhesion in contact. In addition, signs of a  liquid phase were observed on the copper contact surface. It promoted the low rate of formation and accumulation of structural defects. Emergence of areas of melt and FeO oxide on the sliding surface provides high contact wear resistance. These factors, combined with the high thermal copper conductivity, have caused the tribolayer transition to the limit state at high current density and low contact temperature. The absence of oxides on the sliding surface of the NiTi alloy has caused strong adhesion in the contact, high rate of formation and accumulation of structural defects. Therefore, the tribolayer quickly deteriorates and high wear intensity and rapid increase in the contact temperature are observed with current density increase. Therefore, the catastrophic wear of the NiTi alloy begins at a temperature about 350  °C and at low current density. The sliding surface of AISI 1020 steel contained FeO oxide, therefore strong adhesion is not manifested. Formation of FCC-Fe in tribolayer of AISI steel 1020 is detected, that promotes its accelerated deterioration. Therefore, the tribolayer of AISI steel  1020 transites to the utmost state at a relatively low current density and at a  higher temperature. The presented contact temperatures corresponding to the beginning stages of the utmost state of the tribolayer do not exceed 350  °С. Comparison of these temperatures with the known contact temperatures of other metals made it possible to assert that raising of the contact temperature of any metal higher than 400  °С leads to its utmost state. Therefore the characteristics of metals contact at temperatures of sliding contact higher than 500  °С is not of practical interest.

Microstructural Evolution in Worn Surface Layer of T10 against 20CrMnTi Steels after Dry Sliding Friction

2014 ◽  
Vol 692 ◽  
pp. 282-287 ◽  
Author(s):  
Xin Wang ◽  
Rong Bin Li ◽  
Jing Zhang
Keyword(s):  
Surface Layer ◽  
Microstructural Evolution ◽  
Sliding Friction ◽  
Normal Load ◽  
Dry Sliding ◽  
Friction Test ◽  
Pin On Disc ◽  
Steel Disc ◽  
Dry Sliding Friction ◽  
Worn Surface

The dry sliding friction test of normalized T10 steel against hardened quenched and tempered 20CrMnTi steel under normal load of 60 N and sliding speed of 0.29m/s was carried out on a pin-on-disc tribo-tester. The microstructures in the worn surface layer of T10 steel pin and 20CrMnTi steel disc were analyzed by OM, SEM, and TEM, which were all severely plastically deformed. The ultrafine and even nanoferrite grains (5 nm to 200 nm) were observed in the worn surface layer of T10 steel pin, which was considered to be the result of severely shear deformation.

Interaction of tungsten in dry sliding against steel under high density electric current

2019 ◽  
pp. 101-109 ◽  
Author(s):  
M. I. Aleutdinova ◽  
V. V. Fadin ◽  
Yu. P. Mironov
Keyword(s):  
Electrical Contact ◽  
Analysis Data ◽  
Dry Sliding ◽  
Sliding Surface ◽  
X Ray ◽  
Sliding Surfaces ◽  
Quenched Steel ◽  
Sliding Electrical Contact ◽  
A Current ◽  
Tungsten Steel

The possibility of creating a wear-resistant dry sliding electrical contact tungsten/steel was studied. It was shown that tungsten caused severe wear of the quenched steel counterbody due to unlimited plastic flow of its surface layer at a current density up to 150 A/cm2 . This indicated the impossibility of achieving satisfactory characteristics of such a contact. Low electrical conductivity and wear resistance of the contact tungsten/steel were presented in comparison with the known high copper/steel contact characteristics under the same conditions. X-ray phase analysis data of the steel sliding surfaces made it possible to state that the cause of the unsatisfactory sliding of tungsten was the absence of the necessary concentration of FeO oxide on the sliding surface of the steel. 

Deposition and Tribological Properties of CVD Diamond/Diamond-Like Carbon Composite Films

2012 ◽  
Vol 565 ◽  
pp. 615-620
Author(s):  
Bin Shen ◽  
Liang Wang ◽  
Su Lin Chen ◽  
Fang Hong Sun
Keyword(s):  
Surface Morphology ◽  
Composite Film ◽  
Tribological Properties ◽  
Composite Films ◽  
Cvd Diamond ◽  
Carbon Composite ◽  
Dry Sliding ◽  
Diamond Like Carbon ◽  
Dlc Film ◽  
Bonding State

The CVD diamond/diamond-like carbon composite film is fabricated on the WC-Co substrate by depositing a layer of Diamond-like Carbon film on the surface of conventional Micro- or Nano-crystalline diamond film. The hot filament chemical vapor deposition (HFCVD) method and vacuum arc discharge with a graphite cathode are adopted respectively to deposit the MCD/NCD and DLC films. A variety of characterization techniques, including filed emission scanning electron microscope (FE-SEM) and Raman spectroscopy are employed to investigate the surface morphology and atomic bonding state of as-deposited MCD/DLC and NCD/DLC composite film. The results show that both MCD/DLC and NCD/DLC composite films present similar surface morphology with the MCD and NCD films, except for scattering a considerable amount of small-sized diamond crystallites among the grain boundary area. The atomic-bonding state of as-deposited MCD/DLC and NCD/DLC composite films is determined by the top-layered DLC film, which is mainly consisted of amorphous carbon phase and no discernible sp3 characteristic peak can be observed from their Raman spectrum. Furthermore, the tribological properties of as-deposited MCD/DLC and NCD/DLC composite films is examined using a ball-on-plate reciprocating friction tester under both dry sliding and water-lubricating conditions, comparing with conventional DLC, MCD and NCD films. Silicon nitride balls are used as counterpart materials. For the CVD diamond/DLC composite films, the self-lubricating effect of top-layered DLC film is beneficial for suppressing the initial friction peak, as well as shortening the run-in period. The average friction coefficients of MCD/DLC and NCD/DLC composite films during stable sliding period are 0.07 and 0.10 respectively in dry sliding; while under water-lubricating condition, they further decreases to 0.03 and 0.07.

Study on Electrodeposition of Ni-Graphite Composite Coatings in Sulfamate Bath

2010 ◽  
Vol 150-151 ◽  
pp. 1546-1550 ◽  
Author(s):  
Xiang Zhu He ◽  
Xiao Wei Zhang ◽  
Xin Li Zhou ◽  
Zhi Hong Fu
Keyword(s):  
Surface Morphology ◽  
Process Parameters ◽  
Current Density ◽  
Graphite Particle ◽  
Particle Concentration ◽  
Composite Coatings ◽  
Nickel Matrix ◽  
Graphite Composite ◽  
Surface Morphologies ◽  
Sulfamate Bath

This paper presented the composite coatings of nickel with graphite particle on the aluminum substrate using a nickel sulfamate bath. Effects of graphite particle concentration on the surface morphologies of the composite coatings were investigated. The inclusion of graphite particle into metal deposits was dependent on many process parameters, including particle concentration, current density, pH and temperature. Results of SEM and XRD demonstrated that graphite particle had successfully deposited on that nickel matrix; besides, the surface morphology of coatings obtained from sulfamate bath containing 2g/L graphite particle dispersed more uniformly than the ones with higher concentration.

scholarly journals Liquid Phase Synthesis of CoP Nanoparticles with High Electrical Conductivity for Advanced Energy Storage

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Guo-Qun Zhang ◽  
Bo Li ◽  
Mao-Cheng Liu ◽  
Shang-Ke Yuan ◽  
Leng-Yuan Niu
Keyword(s):  
Electrical Conductivity ◽  
Energy Storage ◽  
Liquid Phase ◽  
Specific Capacitance ◽  
Current Density ◽  
High Surface ◽  
High Surface Area ◽  
High Energy ◽  
High Energy Density ◽  
Energy Storage Materials

Transition metal phosphide alloys possess the metalloid characteristics and superior electrical conductivity and are a kind of high electrical conductive pseudocapacitive materials. Herein, high electrical conductive cobalt phosphide alloys are fabricated through a liquid phase process and a nanoparticles structure with high surface area is obtained. The highest specific capacitance of 286 F g−1 is reached at a current density of 0.5 A g−1. 63.4% of the specific capacitance is retained when the current density increased 16 times and 98.5% of the specific capacitance is maintained after 5000 cycles. The AC//CoP asymmetric supercapacitor also shows a high energy density (21.3 Wh kg−1) and excellent stability (97.8% of the specific capacitance is retained after 5000 cycles). The study provides a new strategy for the construction of high-performance energy storage materials by enhancing their intrinsic electrical conductivity.

Dry Sliding Wear Behavior of Hot Pressed Fe-28Al and Fe-28Al-10Ti Alloys

2011 ◽  
Vol 306-307 ◽  
pp. 425-428
Author(s):  
Jing Li ◽  
Xiao Hong Fan ◽  
De Ming Sun
Keyword(s):  
Plastic Deformation ◽  
Sliding Wear ◽  
Wear Behavior ◽  
Wear Test ◽  
Dry Sliding Wear ◽  
Dry Sliding ◽  
Long Distance ◽  
Wear Performance ◽  
Testing Conditions ◽  
Worn Surface

Fe-28Al and Fe-28Al-10Ti alloys were prepared by mechanical alloying and hot pressing. The phases and dry sliding wear behavior were studied. The results show that Fe-28Al bulk materials are mainly characterized by the low ordered B2 Fe3Al structure with some dispersed Al2O3 particles. Fe-28Al-10Ti exhibits more excellent wear resistance than Fe-28Al, especially after long distance sliding wear test. There are obvious differences in wear mechanisms of Fe-28Al and Fe-28Al-10Ti alloys under different testing conditions. Under the load of 100N, there is plastic deformation on the worn surface of Fe-28Al. The main wear performance of Fe-28Al-10Ti is particle abrasion, the characteristics of which are micro cutting and micro furrows, but micro-crack and layer splitting begin to form on the surface of Fe-28Al. Under the load of 200N, serious plastic deformation and work-hardening lead to rapid crack propagation and eventually the fatigue fracture of Fe-28Al. Plastic deformation is the main wear mechanism of Fe-28Al-10Ti under the load of 200N, which are characterized by micro-crack and small splitting from the worn surface.

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