Influence of MoS2, H3BO3, and MWCNT Additives on the Dry and Lubricated Sliding Tribology of AMMC–Steel Contacts

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Harpreet Singh ◽  
ParamPreet Singh ◽  
Hiralal Bhowmick
Keyword(s):  
Carbon Nanotubes ◽  
Friction And Wear ◽  
Wear Behavior ◽  
Preliminary Investigation ◽  
Multiwall Carbon Nanotubes ◽  
Operating Conditions ◽  
Matrix Composites ◽  
Base Oil ◽  
Oil Additives ◽  
Multiwall Carbon

The present study is focused on the performance evaluation of MoS2, H3BO3, and multiwall carbon nanotubes (MWCNT) used as the potential oil additives in base oil for aluminum metal matrix composites (AMMC)–steel (EN31) tribocontact. Al–B4C composite is used for this purpose; based on a set of preliminary investigation under unlubricated and fresh oil lubrication, three different types of AMMCs (Al–SiC, Al–B4C, and Al–SiC–B4C) were used. A pin-on-disk tribometer is used for all the friction and wear tests under operating condition of load 9.8 N and sliding velocity of 0.5 m/s. From the particle-based wet tribology, it is clear that both the additives H3BO3 and MWCNT improve the friction as well as wear behavior for selected composite contacts. Multiwall carbon nanotubes emerged out as superior among all the additives, whereas MoS2 additives show marginal enhancement in frictional performance under given operating conditions. Fractography and morphological study of pin specimens are carried out to identify the underlying friction and wear mechanisms.

Nano and macromechanical properties of aluminium (A356) based hybrid composites reinforced with multiwall carbon nanotubes/alumina fiber

2016 ◽  
Vol 51 (11) ◽  
pp. 1631-1642 ◽  
Author(s):  
JSS Babu ◽  
A Srinivasan ◽  
CG Kang
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Hybrid Composites ◽  
Multiwall Carbon Nanotubes ◽  
Matrix Composites ◽  
Weight Percentage ◽  
Continuous Stiffness Measurement ◽  
Multiwall Carbon

Nano-microhybrid reinforced metal matrix composites are the novel combination of composite system which enhanced the mechanical properties of the metal matrix composites. The aim of this study is to determine the nano- and macromechanical properties of aluminium (A356)-based hybrid composites reinforced with multiwall carbon nanotubes and alumina short fibers (Al2O3sf). Hybrid preforms were developed initially, by a combination of multiwall carbon nanotubes and Al2O3sf with total volume fractions of 10%, 15% and 20% and by varying the weight percentage of multiwall carbon nanotubes such as 1%, 2% and 3%. The fabricated hybrid preforms were then infiltrated with aluminium alloy (A356), and the microstructure and mechanical properties of the composites were evaluated. The distribution of multiwall carbon nanotubes within the array of the Al2O3sf network which exists in clusters was found to be relatively good. The mechanical properties such as the hardness and tensile strength of Al-based hybrid metal matrix composites were found to be improved by up to 2 wt% of multiwall carbon nanotubes. The causative reason for this is attributed to a combined effect of both multiwall carbon nanotubes and Al2O3sf, which contributed to better load sharing between the fibers and the Al matrix, and also accounted for the resistance of dislocation movements caused by the presence of the multiwall carbon nanotubes. In addition, the continuous stiffness measurement method was also used to evaluate the nanomechanical properties of the composites. The results showed that the influence of multiwall carbon nanotubes highlighted the properties on a nanoscale.

Wear Behavior of Polyester – Carbon Nanotubes Composites under Dry Sliding Ball-on-Flat Reciprocating Test

2015 ◽  
Vol 809-810 ◽  
pp. 1169-1174
Author(s):  
Adrian Cotet ◽  
Luminita Ciupagea ◽  
Dumitru Dima ◽  
Gabriel Andrei
Keyword(s):  
Carbon Nanotubes ◽  
Friction Coefficient ◽  
Wear Rate ◽  
Abrasive Wear ◽  
Wear Behavior ◽  
Multiwall Carbon Nanotubes ◽  
Dry Sliding ◽  
Linear Wear ◽  
Linear Wear Rate ◽  
Multiwall Carbon

Friction coefficient and linear wear rate of polyester-carbon nanotubes composites were investigated through ball-on-flat reciprocating test, under dry sliding contact. Three types of nanoscopic fillers were used: multiwall carbon nanotubes (MWCNT), functionalized multiwall carbon nanotubes (MWCNT-COOH) and singlewall carbon nanotubes (SWCNT), with three values of weight content 0.1, 0.15 and 0.2 wt%. Comparative analysis was done for polyester and its composites tested over 14 m sliding distance, under three values of load, 30 N, 40 N and 50 N. Composites containing MWCNT underwent a decrease in friction coefficient and linear wear rate only in case of 50N loading. An improvement of wear behavior under 50N loading was obtained for the composite with 0.10 wt% functionalized carbon nanotubes. Generally, better values of wear rate at 50 N loading were recorded in case of composites with 0.15 wt% and 0.20 wt% MWCNT and SWCNT, respectively. Optical and electronic investigation of the worn surfaces revealed the occurrence of abrasive, adhesive and fatigue wear. Abrasive wear is due to the hard particles detached from the counterpart which produce scratches and furrows on sliding track. Adhesive wear results when soft particle of polymer are caught and blocked among the asperities of counterpart, and it develops over a local area, being influenced by temperature rise. Fatigue and abrasive wear are responsible for the formation of the 3rd body between contacting parts which affects the friction and wear behavior. Morphological analysis of worn surface showed the rise of transfer film that induces instability of wear parameters.

Boehmite Nanofibers as a Dispersant for Nanotubes in an Aqueous Sol

2018 ◽  
Author(s):  
Gen Hayase
Keyword(s):  
Carbon Nanotubes ◽  
Aspect Ratio ◽  
Aqueous Solutions ◽  
High Aspect Ratio ◽  
Multiwall Carbon Nanotubes ◽  
Multiwall Carbon ◽  
Nanotube Films

By exploiting the dispersibility and rigidity of boehmite nanofibers (BNFs) with a high aspect ratio of 4 nm in diameter and several micrometers in length, multiwall-carbon nanotubes (MWCNTs) were successfully dispersed in aqueous solutions. In these sols, the MWCNTs were dispersed at a ratio of about 5–8% relative to BNFs. Self-standing BNF–nanotube films were also obtained by filtering these dispersions and showing their functionality. These films can be expected to be applied to sensing materials.

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