文章信息/Info

Title:

Tribological Behavior Investigation of Polytetrafluoroethylene Composite Coating Reinforced with Modified Nano-Silicon Nitride

文章編號:

1674-3962(2022)07-0578-06

作者:

周紅成; 卞達; 劉雅玄; 郭永信; 趙永武

（江南大學機械工程學院，江蘇 無錫 214122）

Author(s):

ZHOU Hongcheng;  BIAN Da;  LIU Yaxuan;  GUO Yongxin;  ZHAO Yongwu

(School of Mechanical Engineering, Jiangnan University, Wuxi 214122, China)

關鍵詞:

氮化硅; 聚四氟乙烯; 摩擦系數; 磨損率

Keywords:

silicon nitride;  polytetrafluoroethylene;  friction coefficient;  wear rate

分類號:

TQ325.4;TB383

DOI:

10.7502/j.issn.1674-3962.202101003

文獻標志碼:

A

摘要:

聚四氟乙烯（PTFE）在減摩材料領域應用廣泛，但其較差的耐磨性限制了其應用。納米材料改性是改善PTFE耐磨性的一種有效方法，而氮化硅（Si3N4）的強度高、摩擦系數低，能夠與PTFE實現功能互補。以PTFE和硅烷偶聯劑KH-570改性的Si3N4為填料、聚酰胺酰亞胺（PAI）為粘結劑，采用噴涂�补袒�的方法制備了PTFE/Si3N4復合涂層，并對該涂層的摩擦學性能展開了研究。利用掃描電子顯微鏡（SEM）和傅里葉變換紅外光譜（FT-IR）對改性前后的Si3N4納米顆粒進行表征；利用顯微硬度測試儀和摩擦磨損試驗機對PTFE/Si3N4復合涂層的綜合性能進行表征。研究結果表明：KH-570成功接枝到了Si3N4納米顆粒的表面，接枝后Si3N4納米顆粒的表面更加粗糙，有利于其均勻分散；Si3N4納米顆粒可以改善PTFE/Si3N4復合涂層的硬度和摩擦學性能。當改性Si3N4納米顆粒的質量分數為1%時，復合涂層的硬度最高，為11.1HV，摩擦系數和磨損率最低，分別為0.0755和3.78×10-3 m3·N-1·m-1，磨損方式為磨粒磨損。當加入過多的改性Si3N4納米顆粒時，其會出現團聚，復合涂層的摩擦磨損性能下降。

Abstract:

Polytetrafluoroethylene (PTFE) is widely used in the field of antifriction materials, but its poor wear resistance limits its application. Nanomaterial modification is an effective method to improve the wear resistance of PTFE. Silicon nitride (Si3N4) has high strength and low-friction-coefficient properties, which can overcome the poor wear resistance of PTFE. With modified Si3N4 and PTFE as raw materials and polyamideimide (PAI) as binder, the PTFE/Si3N4 composite coating is prepared by spraying-curing method, and the tribological properties of the coating are investigated. The structure of Si3N4 nanoparticles before and after modification is characterized using scanning electron microscope (SEM) and fourier transform infrared spectroscopy (FT-IR). In addition, the hardness and tribological behavior of the coating are also studied by microhardness tester and friction and wear tester. The results show that KH-570 has been successfully grafted on the surface of Si3N4 nanoparticles, and the surface of modified Si3N4 nanoparticles becomes rougher, which is benefit for the dispersion of Si3N4 nanoparticles. Besides, Si3N4 nanoparticles can improve the hardness and tribological properties of the PTFE composite coating. When the mass fraction of modified Si3N4 nanoparticles is 1%, the coating achieves the highest hardness (11.1HV) among the samples. And the friction coefficient and wear rate are 0.0755 and 3.78×10-3 m3·N-1·m-1 respectively, which is the lowest friction coefficient and wear rate among the samples. At this time, the wear mechanism of the coating is mainly abrasive wear. However, when too much modified Si3N4 nanoparticles is added, the serious agglomeration occurs, which will reduce the tribological properties of the coating.