| Tribological investigation of CaF2 nanocrystals as grease additives | |
| Department | 固体润滑国家重点实验室 |
Wang LB(王李波); Wang B(王博) ; Wang XB(王晓波); Liu WM(刘维民)
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| 2007 | |
| Source Publication | Tribology International
 |
| ISSN | 0301-679X |
| Volume | 40Pages:1179-1185 |
| Abstract | Calcium fluoride (CaF2) nanocrystals with average grain size of 60nm were synthesized via a precipitation method. The morphology and structure of nanocrystals were characterized by means of transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). TEM and XRD showed that CaF2 nanocrystals are cubic particles in submicron scale. The tribological properties of the prepared CaF2 nanocrystals as an additive in lithium grease were evaluated with a four-ball tester. The results indicated that these nanocrystals exhibit excellent antiwear, friction reduction and extreme pressure (EP) properties. It was also found that the EP and antiwear capabilities of the grease are not proportional to the content of CaF2 nanocrystals but there existed a certain value. The rubbed surface after friction test was investigated with X-ray photoelectron spectroscopy and scanning electron microscopy to understand the action mechanism. The results show that a boundary film mainly composed of CaF2, CaO, iron oxide and some organic compounds was formed on the rubbed surface after friction test and the thickness of boundary film was about 12 nm. The disproportion of stoichiometric ratio of Ca and F in boundary lubrication film indicates that tribochemical reaction of CaF2 nanocrystals occurred on the worn steel surface at severe tribological conditions. |
| Keyword | Caf2 Nanocrystals Lubrication Additive Antiwear Lithium Grease |
| Subject Area | 材料科学与物理化学 |
| Funding Organization | the “Innovative Group Foundation” from NSFC (Grant no. 50421502) |
| Indexed By | SCI |
| Language | 英语 |
| Funding Project | 空间润滑材料组 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.licp.cn/handle/362003/4007 |
| Collection | 固体润滑国家重点实验室（LSL） |
| Corresponding Author | Liu WM(刘维民) |
| Recommended Citation GB/T 7714 | Wang LB,Wang B,Wang XB,et al. Tribological investigation of CaF2 nanocrystals as grease additives[J]. Tribology International,2007,40:1179-1185. |
| APA | 王李波,王博,王晓波,&刘维民.(2007).Tribological investigation of CaF2 nanocrystals as grease additives.Tribology International,40,1179-1185. |
| MLA | 王李波,et al."Tribological investigation of CaF2 nanocrystals as grease additives".Tribology International 40(2007):1179-1185. |
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| File Name/Size | DocType | Version | Access | License | ||
| 20071179-1185.pdf（1042KB） | 开放获取 | CC BY-NC-SA | View Application Full Text | |||
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