The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive mod...The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures （plain, twill 1/3 and satin 8/5） of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy （SEM）. The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions： the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.展开更多
The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the po...The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the polymer-based composite.Unfortunately,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite scarce.Therefore,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear tester.The scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the counterparts.The tensile properties of the composites are evaluated on the universal material testing machine.The test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania particles.The proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.展开更多
The design of astonishing combinations of benzoxazine resins with various fillers is nowadays of great interest for high quality products,especially in ballistic armors.The objective of this study is to investigate a ...The design of astonishing combinations of benzoxazine resins with various fillers is nowadays of great interest for high quality products,especially in ballistic armors.The objective of this study is to investigate a new hybrid material prepared as multi-layered composite plate by hand lay-up technique.Different composites were manufactured from Kevlar fabrics reinforced polybenzoxazine,which was filled with silane treated microcrystalline cellulose(MCC Si)at various amounts in the interlayers.The developed materials were tested for their flexural,dynamic mechanical and ballistic performance.The aim was to highlight the effect of adding different amounts of MCC Si on the behavior of the different plates.Compared to the baseline,the dynamic mechanical and bending tests revealed an obvious decrease of the glass transition of 21℃and a notable increase in storage modulus and flexural strength of about 180%and17%,respectively,upon adding 1%MMC Si as filler.Similarly,the ballistic test exhibited an enhancement in kinetic energy absorption for which the composite supplemented with 1%MCC Si had the maximal energy absorption of 166.60 J.These results indicated that the developed panels,with interesting mechanical and ballistic features,are suitable to be employed as raw materials to produce body armor.展开更多
The mechanical properties and material volume fractions of PTFE/Kevlar49/PA6 composite are studied. The focus of this paper is to get the relationship between the volume fraction of three constituents and the mechanic...The mechanical properties and material volume fractions of PTFE/Kevlar49/PA6 composite are studied. The focus of this paper is to get the relationship between the volume fraction of three constituents and the mechanical properties of the composite by doing tensile, hardness and wear test. The effect of the constituent volume fractions was evaluated. Short Kevlar49 fibers reinforced PA6 （Polyamide 6） with PTFE filler were studied in five different combinations. The results of the experiments show that the mechanical properties increase with Keviar fibers increase, then they decrease after the Kevlar fiber volume reaches one number.展开更多
基金supported by National Defense Foundation of China
文摘The existing research of the woven fabric self-lubricating liner mainly focus on the tribological performance improvements and the service life raised by changing different fiber type combinations, adding additive modification, and performing fiber surface modification. As fabric composites, the weave structures play an important role in the mechanical and tribological performances of the liners. However, hardly any literature is available on the friction and wear behavior of such composites with different weave structures. In this paper, three weave structures （plain, twill 1/3 and satin 8/5） of hybrid Kevlar/PTFE fabric composites are selected and pin-on-flat linear reciprocating wear studies are done on a CETR tester under different pressures and different frequencies. The relationship between the tensile strength and the wear performance are studied. The morphologies of the worn surfaces under the typical test conditions are analyzed by means of scanning electron microscopy （SEM）. The analysis results show that at 10 MPa, satin 8/5 performs the best in friction-reduction and antiwear performance, and plain is the worst. At 30 MPa, however, the antiwear performance is reversed and satin 8/5 does not even complete the 2 h wear test at 16 Hz. There is no clear evidence proving that the tensile strength has an influence on the wear performance. So the different tribological performance of the three weave structures of fabric composites may be attributed to the different PTFE proportions in the fabric surface and the different wear mechanisms. The fabric composites are divided into three regions： the lubrication region, the reinforced region and the bonding region. The major mechanisms are fatigue wear and the shear effects of the friction force in the lubrication region. In the reinforced region fiber-matrix de-bonding and fiber breakage are involved. The proposed research proposes a regional wear model and further indicates the wear process and the wear mechanism of fabric composites.
文摘The Kevlar/polytetrafluroethylene（Kevlar/PTFE） fabric composite can be used as a self-lubricating liner of the self-lubricating bearing.Many types of nano-particles can improve the tribological performance of the polymer-based composite.Unfortunately,up to now,published work on the effect of nano-particles on the tribological performance of the fabric composite which can be used as a self-lubricating liner is quite scarce.Therefore,for the purpose of exploring a way to significantly improve the tribological performance of the fabric composite,the tribological performance of the Kevlar/PTFE fabric composite filled with nano-titania is evaluated by using the block-on-ring wear tester.The scanning electron microscopy is utilized to observe the morphologies of worn surfaces of the fabric composites and the counterparts.The tensile properties of the composites are evaluated on the universal material testing machine.The test results show that the addition of nano-titania at a proper mass fraction of the matrix resin improves the wear resistance and the tensile strength,decreases the friction coefficient,and makes the wear volume of the composite reach a relative steady state more quickly;plastic deformation and microcutting are important for the wear of the fabric composite;a lubricating layer is formed on the worn surface of the composite during sliding,and the lubricating layer is critical for the tribological performance of the composite;the formation and properties of the lubricating layer are influenced by the nano-titania particles.The proposed study on the effect of nano-titania on the tribological performance of the Kevlar/PTFE fabric composite,especially on the evolution of the worn surface of the composite,provides the basis for further understanding of the influence mechanism of the nano-particles on the tribological performance of the composite and explores a method of improving the tribological performance of the composite.
文摘The design of astonishing combinations of benzoxazine resins with various fillers is nowadays of great interest for high quality products,especially in ballistic armors.The objective of this study is to investigate a new hybrid material prepared as multi-layered composite plate by hand lay-up technique.Different composites were manufactured from Kevlar fabrics reinforced polybenzoxazine,which was filled with silane treated microcrystalline cellulose(MCC Si)at various amounts in the interlayers.The developed materials were tested for their flexural,dynamic mechanical and ballistic performance.The aim was to highlight the effect of adding different amounts of MCC Si on the behavior of the different plates.Compared to the baseline,the dynamic mechanical and bending tests revealed an obvious decrease of the glass transition of 21℃and a notable increase in storage modulus and flexural strength of about 180%and17%,respectively,upon adding 1%MMC Si as filler.Similarly,the ballistic test exhibited an enhancement in kinetic energy absorption for which the composite supplemented with 1%MCC Si had the maximal energy absorption of 166.60 J.These results indicated that the developed panels,with interesting mechanical and ballistic features,are suitable to be employed as raw materials to produce body armor.
文摘The mechanical properties and material volume fractions of PTFE/Kevlar49/PA6 composite are studied. The focus of this paper is to get the relationship between the volume fraction of three constituents and the mechanical properties of the composite by doing tensile, hardness and wear test. The effect of the constituent volume fractions was evaluated. Short Kevlar49 fibers reinforced PA6 （Polyamide 6） with PTFE filler were studied in five different combinations. The results of the experiments show that the mechanical properties increase with Keviar fibers increase, then they decrease after the Kevlar fiber volume reaches one number.
