| The disadvantages of engineering plastics such as low hardness and high wear rate will limit its application in more fields.It has become an urgent need to improve the performance of engineering equipment to protect the surface of engineering plastics through some advanced film materials.This paper uses carbon plasma and mixed plasma induction to prepare amorphous carbon-based films on the surface of polytetrafluoroethylene(PTFE)and ultra-high molecular weight polyethylene(UHMWPE)material.It was explored and analyed that plasma-induced in-situ growth of amorphous carbon-based films on the surface of PTFE and UHMWPE materials,and the structural control of in-situ growth of amorphous carbon-based films under different plasma energies was studied.In addition,the wettability,film-base bonding strength and tribological properties of the samples were discussed.The results of the study were as follows(1)By changing the carbon plasma current,amorphous carbon(a-C)films with different thicknesses were prepared on the surface of the PTFE material.The research results showed that under the treatment of carbon plasma current,a series of complex reactions occured on the surface of PTFE material.The in-situ growth mechanism of a-C film on the surface of PTFE material was analyzed.At the same time,it was found that with the increase of the carbon plasma current,the sp2 hybrid carbon of the a-C film in the system increased,and the size of the contact angle decreased.The scratch test showed that this in-situ transformation provided reliable film-base bonding strength.In addition,under a carbon plasma current of 1.5 A,the wear rate decreases from8.47×10-4mm3/Nm to 4.70×10-4mm3/Nm.(2)By changing the carbon plasma current,a-C films with different thicknesses were prepared on the surface of the UHMWPE material.The research results showed that under the treatment of carbon plasma current,the carbon structure on the surface of the UHMWPE material was transformed into an in-situ amorphous carbon structure.,forming an in-situ transformation layer containing organic carbon and amorphous carbon structure was observed in the cross-sectional morphologies.At the same time,it was found that with the increase of the carbon plasma current,the sp2 hybrid carbon of in-situ growth of a-C film on the surface of UHMWPE material increased,and the size of the contact angle decreased.Scratch test showed that in-situ transformation in the form of chemical bonds provided reliable film-base bonding strength.In addition,The wear rates of the UHMWPE material treated with 1.0 A carbon plasma current in the two friction environments were 2.13×10-5mm3/Nm and 1.85×10-5 mm3/Nm,respectively.(3)By pure carbon plasma and mixed plasma treatment,a-C film,a-C/Si film and a-C/Cr film are prepared on the surface of UHMWPE material.The research results showed that after mixed plasma treatment,the in-situ transformation of organic carbon structure on the surface of UHMWPE to amorphous carbon-based composite structure could still be realized,analying the growth mechanism of the in-situ amorphous carbon-based composite film,and finding that the doping elements lead to content of the sp2 hybrid carbon of film in the system was different.Similarly,the in-situ transition layer in the form of chemical bonds increased the the film-base bonding strength The UHMWPE material surface treated with hybrid plasma presented excellent mechanical properties,the hardness of a-C/Si film and a-C/Cr film were 1.13 GPa and 1.30 GPa respectively,while the UHMWPE material treated with pure carbon plasma showed excellent tribological properties.The wear rates under the three loads were 1.71×10-5 mm3/Nm,2.46×10-5mm3/Nm,and 5.16×10-5 mm3/Nm. |
PDF Full Text Request