陶瓷与灰铸铁在水润滑条件下滑动摩擦学特性的研究

在Ｍ－２００环一块磨损试验机上研究了蒸馏水润滑条件下Ｓｉ３Ｎ４、Ａｌ２Ｏ３陶瓷与灰铸铁（ＨＴ）配副时的滑动摩擦磨损特性，并与这两种陶瓷和０．８％Ｃ钢（Ｔ８）配副相对比；在扫描电镜（ＳＥＭ）下对磨损后的试样表面进行了形貌观察和能谱分析。结果表明：Ｓｉ３Ｎ４／ＨＴ的摩擦系数最小，而且Ｓｉ３Ｎ４与ＨＴ的磨损率均比Ｓｉ３Ｎ４与Ｔ８配副时低得多，其原因是由于在灰铸铁表面形成了一层含石墨的氧化膜；Ａｌ２Ｏ３／ＨＴ与Ａｌ２Ｏ３／Ｔ８的摩擦系数差别不大，但灰铸铁的磨损体积小于Ｔ８。这是由于当Ａｌ２Ｏ３与ＨＴ配副时，很难在ＨＴ表面形成含石墨的表面膜，但ＨＴ中的石墨膜减轻了Ｆｅ向Ａｌ２Ｏ３表面的转移从而降低了磨损。     

蒸馏水润滑下Si_3N_4-白口铸铁摩擦面上表面膜形成过程的观察

为了观察蒸馏水润滑下的Ｓｉ３Ｎ４—白口铸铁摩擦面上表面膜的形成过程,在环—块磨损试验机上进行了不同磨程的磨损试验,通过扫描电镜（ＳＥＭ）对不同磨程的铸铁磨面进行了观察,对表面膜的形成机理进行了初步探讨。结果表明,当Ｓｉ３Ｎ４与白口铸铁配副摩擦时,由于铸铁中碳化物的剥落而形成剥落坑,Ｓｉ３Ｎ４磨屑嵌入剥落坑并氧化和水解,其反应产物富集于剥落坑中,脱水聚合后形成硅胶,从而在磨面形成了含硅胶的表面膜。表面膜的形成保护了陶瓷和铸铁磨面,使其变得很光滑,从而使摩擦系数降至０．０２,并使陶瓷和铸铁的磨损几乎接近于零。     

蒸馏水润滑下Si3N4—白口铸铁摩擦面上表面膜形成过程 …

为了观察蒸馏水润滑下的Ｓｉ３Ｎ４－白口铸铁摩擦面上表面膜的形成过程,在环－块磨损试验机上进行了不同磨程的磨损试验,通过扫描电镜（ＳＥＭ）对不同磨程的铸铁磨面进行了观察,对表面膜的形成机理进行了初步探讨。结果表明,当Ｓｉ３Ｎ４与白口铸铁配副摩擦时,由于铸铁中碳化物的剥落而形成剥落坑,Ｓｉ３Ｎ４磨屑嵌入剥落坑并氧化和水解,其反应产物富集于剥落坑中,脱水聚合后形成硅胶,从而在磨面形成了含硅胶的表面膜。表     

陶瓷与灰铸铁配副在水润滑下的摩擦学性能

比较了在蒸馏水润滑下Si3N4、Al2O3陶瓷与灰铸铁副的摩擦学性能,结果表明：Al2O3陶瓷的磨损体积远小于Si3N4,但与Si3N4配副时灰铸铁的磨损体积明显小于与Al2O3配副时的磨损体积。其摩擦系数也较小（0.02)。用SEM观察发现Al2O3陶瓷磨擦表面粗糙,有少量的转移膜形成;而Si3N4磨擦表面光滑,与其对应的灰铸铁磨面上存在含石墨的润滑膜。     

球墨铸铁与Al2O3陶瓷的滑动摩擦磨损

研究了球墨铸铁与Ａｌ２Ｏ３陶瓷配副在空气,蒸馏水,乳化液和油润滑条件下的摩擦磨损特性。结果表明,随着了,蒸馏水,乳化液和油润滑顺序,Ａｌ２Ｏ３陶瓷和铸铁副的摩擦系数及各自的磨损量都逐渐降低。     

钢与Si3N4摩擦副中边界膜生成机理的探讨

边界摩擦是摩擦副经常出现的一种状态,论述了钢与Ｓｉ３Ｎ４（氮化硅）摩擦副边界润滑机理,指出了在钢表面形成化学反应膜的过程及在Ｓｉ３Ｎ４表面能生成吸附膜,探讨了软金属沉积在Ｓｉ３Ｎ４表层及亚表层从而形成一层软金属润滑层的方法。     

Ni—P—Si3N4复合镀层的磨损特性

本文通过Ｘ射线衍射分析、电子探针分析和摩擦磨损试验，分析了电沉积Ｎｉ－Ｐ－Ｓｉ３Ｎ４复合镀层的结构性能和磨损特性，并比较了不同弥散微粒的影响。结果表明，在油润滑条件下，复合镀层中的Ｓｉ３Ｎ４微粒在支承载荷的同时，有利于边界润滑膜的形成，避免粘着磨损。同时由于Ｓｉ３Ｎ４微粒本身具有的结构特征，提高了复合镀层的耐磨性能。     

水润滑陶瓷轴承的试验研究

使用Ｓｉａｌｏｎ，ＺｒＯ２和Ａｌ２Ｏ３陶瓷材料，进行了水润滑条件下的滚动轴承和滑动轴承的试验研究，比较和分析了各种陶瓷材料的疲劳和磨损特性，滚动轴承中Ｓｉａｌｏｎ球的寿命最长，Ａｌ２Ｏ３球的寿命最短，滑动轴承试验中Ｓｉａｌｏｎ的摩擦系数最小，而ＺｒＯ２的磨损较大，借助扫描电子显微镜和Ｘ射线能谱分析讨论了陶瓷的疲劳和磨损机理。     

3Al2O3.2SiO2f／Al—Si复合材料磨损机理

本文通过复合材料磨面，磨屑及亚表层的ＳＥＭ特征分析，研究了３Ａｌ２Ｏ３．２ＳｉＯ２ｆ／Ａｌ－Ｓｉ复合材料的润滑衣干滑动磨损机理。润滑状态下复合材料的耐磨性大大优于Ａｌ－Ｓｉ合金，其磨损为纤维断裂与剥落及磨粒磨损；而复合材料在干滑动条件下的耐磨性反而稍差于Ａｌ－Ｓｉ合金，其磨损为粘着磨损，磨粒磨损和层离剥落。     

PTFE基复合材料海水润滑下的摩擦学性能研究

研究碳纤维/聚四氟乙烯（CF/PTFE）、玻璃纤维/聚四氟乙烯（GF/PTFE）复合材料与氮化硅陶瓷配副在海水环境下的摩擦学性能与润滑机制,分析滑动速度对摩擦副海水润滑性能的影响规律。结果表明：在海水润滑条件下,随着滑动速度的增加,PTFE、CF/PTFE、GF/PTFE材料与Si3N4陶瓷配副时的摩擦学性能均有明显改善,摩擦因数与磨损率均呈显著降低的趋势,其中CF/PTFE复合材料表现出更为优异的摩擦学性能,在1 000 r/min滑动速度下摩擦因数低至0.026。磨损表面表征结果表明,在海水润滑条件下,PTFE基复合材料在摩擦过程中由于摩擦化学反应生成了润滑膜,可为摩擦副提供良好的润滑和减磨作用,从而减少摩擦磨损行为的发生。     

An investigation on component and formation of tribochemical film in Si3N4-white iron sliding pair lubricated with distilled water

A tribofilm was formed during wear tests of a Si₃N₄-white iron pair lubricated with distilled water. In order to clarify the formation of the film, the wear tests for Si₃N₄-white iron pair with different sliding distances were carried out on a ring-block tester, using distilled water as lubricant. The worn surfaces of white iron specimens were observed under SEM. Furthermore, the component and structure of the film were analyzed by using AES, XPS, FTIR and XRD. From the investigation, the following results are presented. During the wear tests of Si₃N₄-white iron pair lubricated with distilled water, the oxidation and hydrolysis of Si₃N₄ occur on the wearing surfaces, and a tribochemical film, which mainly consists of silica gel, is formed on the wearing surface. The reason for the film formation is that the carbides in cast iron spall off during the wearing tests and the spalling pits are left on the wearing surface of the white iron. Then, the debris of Si₃N₄ or its oxidized product are embedded into the pits, and are further oxidized and hydrolyzed. The products of reactions are concentrated in the pits and polycondensed into silica gel, and a silica gel film is formed on the wearing surface. The film protects both Si₃N₄ and white iron, and makes the paired surfaces smooth. Therefore, the friction coefficient of the pair is down to 0·02, and the wear rates of Si₃N₄ and iron are near zero. However, because the resultants of oxidation and hydrolysis of Si₃N₄ can not be enriched on the wearing surface of carbon steel to form an effective tribofilm, both friction coefficient and wear rate of Si₃N₄-carbon steel pair lubricated with distilled water are still high in value.     

Effect of lubricants on the friction and wear of Al2O3 against gray cast iron

The tribological behavior of ceramic Al₂O₃ coupled with gray cast iron (PHT) with different lubricants was investigated using a ring-on-block wear tester. In the wear test, air, distilled water, emulsion and oil were used as lubricants respectively in order to check the lubricating effectiveness of lubricants and the friction mechanism of solid graphite in the cast iron. Wear testing of 0.8% C steel (T8) sliding with Al₂O₃ was also carried out to compare with the test using gray cast iron. From these data the tribological behavior of graphite in the iron can be evaluated. The results show that the friction and wear of tested couples are decreased using different lubricants in the following order: air, distilled water, emulsion and oil. When lubricating with air and water, graphite in the iron as solid lubricant can decrease the friction and wear of the couples. However, when lubricating with emulsion and oil, graphite does not show the advantage of decreasing friction and wear.     

高水基液压阀陶瓷摩擦副摩擦学性能研究

为选择适合的高水基乳化液液压阀摩擦副材料,探讨ZrO2与不同结构陶瓷组成的摩擦副在高水基乳化液润滑状态下的摩擦磨损特性。采用摩擦磨损试验机,在不同载荷和滑动速度下,研究在高水基乳化液介质中4种不同陶瓷材料（ZrO2、Al2O3、Si3N4和SiC）分别与ZrO2配副的摩擦学性能,并探讨不同组合陶瓷摩擦副的磨损机制。结果表明：在高水基乳化液中,各陶瓷的摩擦因数均随着滑动速度的增大而降低,其中Al2O3陶瓷的摩擦因数最小;ZrO2、Al2O3和Si3N4陶瓷的摩擦因数受载荷的影响较小,SiC陶瓷的摩擦因数则随着载荷的增大而骤增;各陶瓷的磨损体积都随着速度和载荷的增大而增大,其中Al2O3/ZrO2陶瓷摩擦副的磨损体积最小,其磨损机制以磨粒磨损和微疲劳磨损为主。研究表明,在不同工况下,Al2O3与ZrO2陶瓷配副的摩擦因数和磨损体积均为最低值,更适合作为高水基乳化液液压阀的摩擦副材料。     

Friction and wear of grey cast iron against Si3N4 in emulsion and water

Friction and wear tests of Si₃N₄ against cast iron were carried out using a ring-on-block tester lubricated by emulsion. To provide a comparison with emulsion, distilled water was also used as a lubricant in the tests. The results show that emulsion can prevent the formation of an SiO₂·2H₂O film on the iron surface. Although the friction coefficient of Si₃N₄/ iron pairs in emulsion is much greater than in distilled water, the wear of Si₃N₄ in emulsion is less.     

Al2O3/TiC/CaF2自润滑陶瓷刀具切削过程中的减摩机理

在Al2O3/TiC陶瓷刀具基体内加入固体润滑剂CaF2来改善其摩擦学特性,制备出Al2O3/TiC/CaF2自润滑陶瓷刀具.以该陶瓷刀具对45钢进行干切削试验,结果表明添加固体润滑剂的Al2O3/TiC/CaF2自润滑刀具的摩擦因数比未添加固体润滑剂的Al2O3/TiC陶瓷刀具显著降低,表现出了良好的减摩效果.在切削过程中,Al2O3/TiC/CaF2自润滑陶瓷刀具中的固体润滑剂由于受到摩擦和挤压作用而析出,能在刀具前刀面上形成润滑膜,可阻止刀-屑间的粘着,显著降低前刀面与切屑间的平均摩擦因数.对自润滑陶瓷刀具切削后磨损表面显微分析表明,前刀面在切削过程中形成了自润滑膜的生成、破损、脱落和再生的循环过程.因此,Al2O3/TiC/CaF2自润滑陶瓷刀具在其整个生命周期内始终具有润滑效果.     

Al2O3、六方BN纳米润滑油的摩擦学性能试验研究

用添加Al2O3以及六方BN纳米颗粒的润滑油对机车发动机易磨损零部件材质制成的摩擦副试样进行摩擦磨损实验,结果表明添加了纳米颗粒的润滑油改善了摩擦副的润滑效果,提高了油膜承载力,降低了摩擦因数。六方BN润滑效果随添加量的增加而增强,中等载荷时质量分数为0.5%的纳米颗粒对3种摩擦副作用相近。Al2O3对硬-软金属配合的摩擦副作用效果强于对硬-硬金属配合的摩擦副,添加量不宜过高。     

硬质合金刀具高能离子源增强多弧镀AlCrTiSiN梯度涂层制备及性能研究

采用离子源增强的多弧离子镀新技术,在硬质合金刀具表面制备了不同含Si层梯度结构的AlCrTiSiN梯度涂层,并对涂层组织结构、残余应力、结合强度、摩擦磨损以及铣削和钻削加工灰铸铁性能进行了详细的研究。结果表明：不同含Si层梯度结构的AlCrTiSiN涂层主要由固溶的(Al,Cr) N、(Al,Ti) N相和非晶态Si₃N₄相组成。其中,含Si层梯度变化最缓和的G3(Gradient 3)涂层具有较高的结合强度,较低的残余压应力、摩擦因数和磨损率。铣削和钻削试验显示,涂层刀具的切削磨损机理主要表现为磨粒磨损和粘着磨损。G3涂层降低了磨粒磨损,其刀具的铣削和钻削寿命均最高,这主要得益于其含Si层的梯度设计、适当的压应力(-3.8 GPa)以及良好的膜基结合强度。研究结果表明,通过对含Si层进行梯度设计可显著提高涂层刀具的切削性能。