scholarly journals Tribological properties of fullerenes C60 and C70 microparticles

1996 ◽  
Vol 11 (11) ◽  
pp. 2749-2756 ◽  
Author(s):  
Wei Zhao ◽  
Jinke Tang ◽  
Ashok Puri ◽  
Ray L. Sweany ◽  
Yuxin Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Friction Coefficient ◽  
Tribological Properties ◽  
Molecular Crystals ◽  
Solid Lubricants ◽  
High Shear ◽  
Fullerenes C60 And C70 ◽  
High Shear Strength ◽  
Hcp Structure

The frictional behaviors of fullerenes C60 and C70 were studied because they were speculated to be solid lubricants. For the sublimated pure C60 films on Si(001), a high friction coefficient (0.55–0.8) was observed under different loads and pin materials. For the C70 film, the friction coefficient showed a pin dependence, which changed from 0.5 with an Al2O3 pin to about 0.9 with a 440 stainless steel pin. The relatively high friction coefficients of C60 and C70 films were due to the tendency of the C60 and C70 particles to clump and compress into high shear strength layers rather than due to the impurities in the fullerenes. The benzene-solvated C60 · 4C6H6 and C70 ·xC6H6 showed a lowered friction coefficient (0.25 for C60 · 4C6H6 and 0.3 for C70 · xC6H6), which might result from the lowered shear strength of the hcp structure of C60 · 4C6H6 and C70 ·xC6H6 molecular crystals in which the benzene molecules were intercalated.

Frictional Behavior of C60 Microparticle-Coated Steel

1995 ◽  
Vol 383 ◽  
Author(s):  
Wei Zhao ◽  
Jinke Tang ◽  
Ashok Purl ◽  
Alexander U. Falster ◽  
William B. Simmons
Keyword(s):  
Stainless Steel ◽  
Shear Strength ◽  
Friction Coefficient ◽  
Ambient Air ◽  
304 Stainless Steel ◽  
Coating Materials ◽  
Uncoated Sample ◽  
Air Atmosphere ◽  
The Coefficient Of Friction ◽  
Hcp Structure

ABSTRACTThe frictional behaviors of 304 stainless steel disks coated with C60 microparticles, both containing benzene and free of benzene, have been studied under different loads and sliding speeds with a pin-on-disk configuration in ambient air atmosphere at room temperature. The results indicated that the coating containing benzene, benzene-solvated C60 microparticles (C60·4C6H6), reduced friction as well as wear. The coated samples showed a 50–70% reduction in friction coefficient in comparison to uncoated samples. Neither the coated nor the uncoated sample showed significant change in friction coefficient for different sliding speeds. Under different loads, the uncoated sample had almost the same friction coefficient. However, with the increase of load, the friction coefficient of C60·4C6H6-coated disk showed a minimum value of 0.25 at 25 g load and then reached the uncoated values beyond 50 g load. The coefficient of friction of the disk coated with benzene-free C60 showed a slight increase with load, reaching the value of uncoated 304 stainless steel disk at about 40 g. The reduced friction of the solvated-C60 coated 304 stainless steel is probably due to the lowered shear strength of the hcp structure of C60·4C6H6 molecular crystal in which the benzene molecules are intercalated. The results of this study suggest the importance of the presence of second component, in addition to C60, in the coating materials in order for them to form a preferred crystal structure with low shear strength as far as using C60 as a solid lubricant is concerned.

Friction and Wear Behaviors of Solid Lubricants/Polyimide Composites in Liquid Mediums

2010 ◽  
Vol 654-656 ◽  
pp. 2763-2766 ◽  
Author(s):  
Li Wen Mu ◽  
Xin Feng ◽  
Yi Jun Shi ◽  
Huai Yuan Wang ◽  
Xiao Hua Lu
Keyword(s):  
Friction Coefficient ◽  
Wear Rate ◽  
Tribological Properties ◽  
Alkaline Solution ◽  
Dry Friction ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Polyimide Composites ◽  
Inorganic Fillers ◽  
Ptfe Composites

The tribological properties of polyimide (PI) composites reinforced with graphite or MoS2 sliding in liquid alkali and water as well as dry friction were investigated using a ring-on-ring tester. The results show that the friction coefficient (μ) and wear rate (W) for both graphite/PI and MoS2/PI composites in different liquid mediums are μdry>μwater >μalkali and Wwater>Wdry >Walkali. Results also indicate that the friction coefficient and wear rate of the PI composites filled with different solid lubricants are μMoS2 >μgraphite and W MoS2 >Wgraphite in different liquid mediums. In addition, the hydrophobic inorganic fillers are fit for the reinforcement of polymer-based composites sliding in liquid mediums. It is also concluded from the authors’ work that the wear rate and friction coefficient of polymer-based (such as PI, PTFE) composites in the alkali lubricated conditions is lowest among all the friction conditions. This may be attributed to the ionic hydration in the alkaline solution.

scholarly journals Evaluasi Kuat Tumpu Alat Sambung Baut pada Papan WPC dari Limbah Sengon dan Plastik HDPE

2016 ◽  
Vol 22 (2) ◽  
pp. 129
Author(s):  
Yudhi Arnandha ◽  
Iman Satyarno ◽  
Ali Awaludin ◽  
Arfiati Fardhani
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Shear Wall ◽  
High Shear ◽  
Wood Plastic Composite ◽  
Bearing Strength ◽  
Plastic Composite ◽  
Structural Purpose ◽  
High Shear Strength ◽  
Bolt Diameter

Wood Plastic Composite (WPC) is wood based material that been produce by mixing sawdust as main composition and plastic polymer as bonding agent. Nowadays, WPC board already been produced in Indonesia using Sengon sawdust and recycle HDPE plastic. Sengon sawdust was used as WPC since its availability from plywood production waste, moreover HDPE plastic considered had higher strength and more rigid than PET plastic. WPC occasionally being used as non structural material, moreover from previous study about mechanical properties of WPC, it was found that WPC Sengon has high shear strength around 25 – 30 MPa. These lead that WPC Sengon had a potential used as shear wall sheathing, thus additional research need to be conducted in order to study the type of bolt and diameter of the bolt can be used for these shear wall. This study aimed to investigate the dowel bearing of bolt using full hole method based on ASTM D5764 with type and bolt diameter as specimen variation. Two types of bolt were used in this study; stainless bolt and standard bolt with diameter each of 6 mm, 8 mm, 10 mm and 12 mm. According to ANOVA, there was insignificant result between stainless bolt and standard one, but there was significant result based on diameter of the bolt. Hereafter, it can be recommended the used of 10 mm diameter of bolt for structural purpose with dowel bearing strength around 67 – 70 MPa.

Sintering mechanism of the Cu–Ag core–shell nanoparticle paste at low temperature in ambient air

RSC Advances ◽  
2016 ◽  
Vol 6 (94) ◽  
pp. 91783-91790 ◽  
Author(s):  
Yanhong Tian ◽  
Zhi Jiang ◽  
Chenxi Wang ◽  
Su Ding ◽  
Jiayue Wen ◽  
...  
Keyword(s):  
Shear Strength ◽  
Low Temperature ◽  
Ambient Air ◽  
Core Shell ◽  
High Shear ◽  
Shell Nanoparticles ◽  
Sintering Mechanism ◽  
High Shear Strength ◽  
Core Shell Nanoparticles

Cu–Ag core–shell nanoparticles owned good anti-oxidation ability, and as-fabricated joints using the Cu–Ag core–shell nanoparticles paste showed high shear strength.

Processing and Characterization of Al-Cu-Mg Alloy Rivets for Aerospace Applications

2012 ◽  
Vol 710 ◽  
pp. 180-185 ◽  
Author(s):  
Niraj Nayan ◽  
S.V.S. Narayana Murty ◽  
Alok Agarwal ◽  
S.C. Sharma ◽  
P.P. Sinha
Keyword(s):  
Shear Strength ◽  
Aluminium Alloy ◽  
Cold Working ◽  
Cold Work ◽  
Mg Alloy ◽  
High Plasticity ◽  
High Shear ◽  
Aerospace Applications ◽  
High Shear Strength

Al-Cu-Mg (Russian grade V65) alloys are used for riveting applications in aerospace industries due to their relatively high shear strength of the order of 25 kg/mm2 combined with a high plasticity. This paper presents the processing of V65 aluminium alloy rivets from wire rods. It was observed that wire rods which have not been intermittently annealed and having more than 25% cold working prior to heading operation, cracked on the free bulged surface of the head. In view of this, it is recommended that a maximum of 25% of cold work is allowed in the wire rods to be used for rivet fabrication to successfully realize defect free rivets.

Syntheses of hyperbranched liquid-crystalline biopolymers with strong adhesion from phenolic phytomonomers

2012 ◽  
Vol 84 (12) ◽  
pp. 2559-2568 ◽  
Author(s):  
Siqian Wang ◽  
Daisaku Kaneko ◽  
Kai Kan ◽  
Xin Jin ◽  
Tatsuo Kaneko
Keyword(s):  
Molecular Weight ◽  
Shear Strength ◽  
Liquid Crystalline ◽  
Hydroxycinnamic Acid ◽  
Carbon Substrate ◽  
High Shear ◽  
High Glass Transition Temperature ◽  
Degradation Temperature ◽  
Strong Adhesion ◽  
High Shear Strength

A novel thermotropic liquid-crystalline (LC) biocopolymer, poly{trans-3-methoxyl-4-hydroxycinnamic acid (MHCA: ferulic acid)-co-trans-3,4-dihydroxycinnamic acid (DHCA: caffeic acid)}, was synthesized by a thermal acidolysis-polycondensation of MHCA and DHCA, efficiently catalyzed by Na2HPO4. When the MHCA composition of poly(MHCA-co-DHCA) was 60, 75, and 90 mol %, the copolymers showed a nematic LC phase although individual homopolymers such as polyMHCA and polyDHCA did not exhibit LC phase. Poly(MHCA-co-DHCA)s showed high molecular weight (Mw) ranged between Mn 2.6 × 104 to 3.7 × 104 and Mw 8.2 × 104 to 13.1 × 104, respectively, high glass-transition temperature (Tg) with the range of 115 to 140 °C and high degradation temperature T10, from 315 to 356 °C. In the adhesive test of copolymers against the surface of carbon substrate, the copolymers showed high shear strength at fracture.

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