本文選題：ZDDP + 摩擦反應膜　； 參考：《中國地質(zhì)大學(北京)》2017年碩士論文

【摘要】：二烷基二硫代磷酸鋅(ZDDP)是一種應用廣泛的汽車潤滑油添加劑,常用于發(fā)動機活塞環(huán)。ZDDP會在摩擦過程中界面處發(fā)生分解,形成的摩擦反應膜通過減小鋼鐵或其它對磨材料表面的金屬與金屬之間的接觸起到保護表面的作用。因為ZDDP在使用時,不僅會使摩擦損耗增加,而且會產(chǎn)生含Zn、P、S的化合物,磷酸鋅和其他的含磷的沉淀物會使三元催化器中毒,而且會影響氧氣傳感器,降低催化轉(zhuǎn)換器的使用效率和壽命。但現(xiàn)在還并未很好的理解摩擦反應膜的生長機制,限制了研究人員進一步開發(fā)具有替代性的并且性能更加優(yōu)異的添加劑。本文為研究ZDDP摩擦反應膜的生長機制,利用超聲冷鍛技術(shù)(UCFT)、真空退火技術(shù),分別在鋼材表面制備了納米化層及不同晶粒尺寸樣品。利用CSM摩擦磨損試驗機考察了不同晶粒尺寸的鋼材表面分別在聚α烯烴合成油(PAO4)和含1.0 wt%二烷基二硫代磷酸鋅(ZDDP)潤滑條件下的摩擦磨損行為。利用掃描電子顯微鏡、金相顯微鏡、三維白光表面形貌儀、X射線衍射儀、顯微硬度計等微觀檢測設(shè)備分析了納米化層的微觀形貌、組織結(jié)構(gòu)和顯微硬度等。利用原子力顯微鏡(AFM)對單微凸體滑動界面上ZDDP分解的摩擦反應膜的生長與性質(zhì)進行原位分析。研究結(jié)果表明:(1)在316L不銹鋼表面制備的納米晶層,最表層平均晶粒尺寸約為12.7nm,表面硬度由190 HV提高到341 HV。真空退火處理后,晶粒尺寸變大。UCFT樣品硬度最高,摩擦系數(shù)和磨損率最小。晶粒的細化有助于使摩擦磨損降低。(2)在單微凸體滑動實驗中,隨著滑移次數(shù)增加,ZDDP摩擦反應膜生長,成核位置隨機分布,探針持續(xù)滑動促進了反應膜的生長。摩擦反應膜具有粗糙、斑塊狀、板狀等形狀特征。UCFT樣品成膜比Untreated樣品成膜速度更快。相同滑移次數(shù)時,UCFT樣品成膜區(qū)域高度更高。這可能是因為納米化處理后表面存在大量的晶界,樣品表面晶粒尺寸變小,晶粒細化并且晶界處的原子密度較低,容易產(chǎn)生更多的斷鍵,從而提高表面活性,促進磨損表面吸附膜或反應膜的形成。(3)單微凸體滑動實驗樣品表面成膜區(qū)域有Zn、P、S等特征元素出現(xiàn),未成膜區(qū)域則沒有,說明ZDDP在摩擦磨損過程中發(fā)生了分解,生成了磷酸鹽摩擦反應膜,起到了抗磨作用。
[Abstract]:Zinc dialkyl dithiophosphate (ZDDP) is a widely used additive for automotive lubricating oil, which is often used in the decomposition of the interface between the piston ring of engine and ZDDP during friction. The formed friction reaction film protects the surface by reducing the contact between metal and metal on the surface of grinding material. Because when ZDDP is used, it not only increases the friction loss, but also produces compounds containing ZnPPU S, zinc phosphate and other phosphorous precipitates can poison ternary catalytic converters and affect oxygen sensors. Reduce the efficiency and lifetime of the catalytic converter. However, the mechanism of friction film growth has not been well understood, which limits the researchers to further develop alternative and better performance additives. In order to study the growth mechanism of ZDDP friction reaction film, nanocrystalline layers and samples of different grain sizes were prepared on the surface of steel by ultrasonic cold forging technique and vacuum annealing technique. The friction and wear behaviors of steel surfaces with different grain sizes under the lubrication conditions of polyolefin synthetic oil (PAO4) and zinc dialkyldithiophosphate (ZDDP) containing 1.0 wt% dialkyl dithiophosphate were investigated by CSM friction and wear tester. The microstructure, microstructure and microhardness of the nanocrystalline layer were analyzed by means of scanning electron microscope, metallographic microscope, three dimensional white light surface topography analyzer and microhardness tester. The growth and properties of friction reaction film decomposed by ZDDP on the sliding interface of a single convex body were analyzed in situ by atomic force microscopy (AFM). The results show that the average grain size of the nanocrystalline layer on the surface of 316L stainless steel is about 12.7 nm, and the surface hardness is increased from 190 HV to 341 HV. After vacuum annealing, the grain size becomes larger. The hardness of UCFT sample is the highest, and the friction coefficient and wear rate are the smallest. The grain refinement is helpful to reduce the friction and wear. 2) in the sliding experiment of single microconvex body, with the increase of slip times, the ZDDP friction reaction film grows, the nucleation position is randomly distributed, and the continuous slippage of the probe promotes the growth of the reaction film. The friction reaction film has the characteristics of rough, patch and plate shape. The film forming rate of UCFT sample is faster than that of Untreated sample. The film forming area of UCFT samples is higher than that of UCFT samples with the same slip times. This may be due to the existence of a large number of grain boundaries on the surface after nanocrystalline treatment. The grain size on the surface of the sample becomes smaller, the grain size is fine and the atomic density at the grain boundary is lower, which makes it easy to generate more broken bonds, thus increasing the surface activity. Promoting the formation of adsorbed or reactive film on wear surface. (3) there are characteristic elements such as ZnPU S in the film forming region of monomicroconvex sliding samples, but not in the unformed film region, which indicates that ZDDP decomposes during friction and wear. A phosphate friction reaction film was formed, which played an anti-wear effect.
【學位授予單位】：中國地質(zhì)大學(北京)
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG174.4
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本文編號：1806482