柴油机出厂摩合过程中磨粒特征参数的统计分析

利用计算机图象技术，本文对铁谱技术进行了改进。用大小磨粒的真实面积和替代了光密度值。对磨粒形貌的数字特征采用了时间过程分析技术，实现了形貌描述的定量化。研究中发现拉缸前大小磨粒出现两极分化现象，其磨损不以切削为主。提出了新的磨合监测指标，采用散射度，欧拉数等特征参数对磨合过程进行了监测，在一定程度上提高了磨损监测的准确性。     

铁谱技术的应用

铁谱技术是从润滑油等工质中分离和分析磨损粒子的新技术。其原理是在高梯度的强磁场作用下,使在润滑油中的磨粒及沾染物分离,按粒度大小依次沉积到一块透明的玻璃基片上,然后对沉积粘度进行光学显微定性观察和对磨粒进行定量测量。这一技术为摩擦磨损机理研究和机械设备的工况诊断、磨损监测、故障预报以及油质评价等开辟了一个新领域。北京型内燃机车的12V240ZJ柴汕机台架磨合规范十几年来一直为17.5小时,这一规范是否先进合理,我们用分析式铁谱仪、直读式铁谱仪和专用形貌仪对五台柴油机磨合期油样内的磨粒浓度、形态、尺寸、数量、粒子分布等进行实验和分析观察并结合形     

初始径向微沟槽对摩擦副磨损性能影响研究

应用线切割技术在摩擦副盘试样上加工沟槽,研究垂直于滑动方向的初始微沟槽对GCr15材料配副的磨损性能影响.采用在线可视铁谱传感器(OLVF)对磨损过程进行在线可视化监测,探究摩擦副的磨损率动态特征,并利用二维轮廓仪、SEM、以及光学金相显微镜对磨痕形貌及特征磨粒进行观测分析.结果显示:与无沟槽实验相比,单沟槽实验中,磨损量与磨损率变化并不显著,磨痕较为光滑;沟槽条数多于4条时,磨合期明显延长,特别是8条沟槽时,磨合期延长约4倍,且磨损率和磨损量增加明显,参数Kt振荡式降低;在沟槽对磨粒的滞存作用下,磨粒磨损得到显著改善,但沟槽数较多时,疲劳磨损愈发显著.因此,少量初始径向微沟槽可以避免磨粒磨损,优化磨合过程.     

油液监测技术在推土机变速箱故障诊断中的应用

综合采用理化性能分析、铁谱分析和原子光谱分析技术等多种油液监测分析技术,对SD16型推土机变速箱润滑油的油品状态、油液中磨粒的大小、形貌及元素种类、含量等进行分析。确定变速箱合理的换油时间,并判断变速箱的磨损部位及磨损状态,为研究变速箱关键零部件的磨损规律打下基础。     

钢质齿轮副在微纳米混合磨合油中的磨合试验研究

将微米和纳米固体粉末单独或混合加入到68#机械油中,配制了5种微米、纳米或微纳米混合磨合油,并试验研究了5种磨合油分别应用于钢质粗糙软齿轮副间的磨合磨损行为和作用机制。研究结果表明:当混合磨合油中微米颗粒粒度比齿面三维粗糙度Sa值小时,磨粒磨损并不显著,且纳米微粒起到加剧磨合磨损的作用。当混合磨合油中微米颗粒粒度比齿面三维粗糙度Sa值大时,磨粒磨损显著,但纳米微粒起到缓和磨合磨损的作用。齿面三维形貌表明纳米颗粒对齿轮副表面有填充作用,对磨合后齿面形貌的结构有较大影响。磨合试验中还发现了因齿面副两表面磨损率差形成的负电阻现象。     

QPQ表面改性层和镀铬层干摩擦状态下磨损特性的研究

在M-2000型摩擦磨损试验机上,对QPQ表面改性层和镀铬层干摩擦状态下的滑动摩擦特性进行对比试验研究,在扫描电子显微镜下观察磨痕的微观形貌,分析2种处理层的磨损机制。结果表明,在磨合阶段,QPQ表面改性层的磨损量较镀铬层的大,而在稳定磨损阶段,QPQ表面改性层的磨损率和摩擦因数均小于镀铬层;在磨合阶段,QPQ表面改性层的磨损机制主要为轻微的磨粒磨损和黏着磨损,镀铬层主要为严重的磨粒磨损,而在稳定磨损阶段,QPQ表面改性层的磨损机制主要为氧化磨损,镀铬层主要为黏着磨损。     

光谱和铁谱及自动磨粒激光技术在油液监测中的应用

在发动机和小轿车手动变速箱齿轮系统中分别对CF-4 15W-40润滑油进行了应用试验,利用光谱、铁谱以及自动磨粒激光技术(LNF)分别对油液进行了监测.结果表明:综合应用3种磨粒技术能够有效及时地对油液进行监测,防止故障发生;当光谱测定的磨损金属和污染元素含量达到极限指标(或经验指标)时,应采用自动磨粒激光技术进行验证;当自动磨粒激光技术测定的磨粒达到50 μm时,应采用铁谱分析,以便准确判断磨损类型.     

基于齿面粗糙度和磨粒分析的齿轮磨损探究

为探究齿轮的磨损过程,以一对直齿圆柱齿轮为研究对象进行齿轮运转试验.在齿轮运转过程中,每2h或4h对齿面进行粗糙度检测并做好记录,每隔1h或2h停机,从齿轮箱中抽取油液,采用油液颗粒分析仪对其磨粒分析,利用LNF-Q210油液分析仪特有的磨粒自动分类功能分析记录切削磨粒、接触滑移磨粒、疲劳磨粒和总磨粒的浓度.试验结束后,对数据进行了处理,结果显示磨粒浓度和粗糙度在不同运转阶段呈现一定的变化趋势.对其进行分析,结论:齿轮运转初期滑移磨粒浓度上升较快,且粗糙度值随齿面磨合而逐渐减小;正常磨损阶段,齿面状态比较稳定,粗糙度值整体变化不大,切削和疲劳磨粒比较平稳,滑移磨粒增加相对较快;齿轮磨损后期,齿面疲劳剥落而快速恶化,粗糙度值快速变大,疲劳磨粒和切削磨粒浓度急剧上升.     

油润滑条件下镍基纳米Al2O3复合刷镀层磨粒的铁谱分析及其磨损机制研究

为研究纳米颗粒复合电刷镀层在含沙粒油润滑条件下的磨损机制，首先制备了镍基纳米Al2O3复合电刷镀层，采用T-11球盘式磨损试验机进行复合刷镀层在含沙粒油润滑条件下的磨损试验，采用FTP-X2型分析式铁谱仪对复合镀层磨损试验后的润滑油中的磨粒形貌进行了研究。结果表明，含磨粒油润滑条件下，复合镀层的磨屑表现出以下3种形貌特征：切削状磨粒、蠕虫状磨粒和岩石状磨粒。这说明，在本实验条件下，复合刷镀层的磨损失效机制主要有磨粒磨损、粘着磨损和疲劳剥层。     

磨合过程的计算机动态仿真

通过将磨损深度与润滑状态联系起来以及对磨合过程中表面形貌变化的计算机模拟，本文提供了一种动态仿真磨合过程的方法，并以缸套、活塞环的磨合过程为例进行了说明。     

Effects of supply of fine oxide particles onto rubbing steel surfaces on severe–mild wear transition and oxide film formation

This study is the first to show a quantitative condition required for the establishment of severe–mild wear transition with sliding distance, by studying the effects of supply of Fe₂O₃ particles onto rubbing steel surfaces on the transition and oxide film formation process. The supply of fine Fe₂O₃ particles was found to accelerate the wear transition, and the sliding distance at which the transition occurs was found to increase with particle diameter and applied load. Oxide films are produced on the rubbing surfaces by sintering of the supplied Fe₂O₃ oxide particles. At the severe–mild wear transition, the relative area of oxide films is the same for all diameters of supplied Fe₂O₃ particles. This finding suggests that the transition occurs when the relative area of oxide films reaches a specific value, which is proportional to the area of real contact.     

In Situ Observation of Wear Process Before and During Scuffing in Sliding Contact

In this study, a direct observation of a point contact area was conducted to understand the scuffing phenomenon. The contact area was produced between a rotating sapphire disc and a stationary steel ball and it was lubricated using n-hexadecane. The image detected by a colour digital CCD camera, load, and friction were synchronously recorded by a computer during the test. It was found that wear debris produced in the contact area played an important role in the wear process, which includes running-in and scuffing. In the test, debris particles accumulated in the inlet zone, and some particles entered the contact area to cause abrasive wear of the ball surface, even in the light-load stages. During the running-in process, the abrasive wear by debris particles changed the conformity between the sliding surfaces. In the high-load stage, just before the occurrence of scuffing, the whole contact area was flattened at once. When scuffing occurred, the contact area suddenly expanded. The conformity of the contact area was dramatically changed during its expansion. The flattening of the whole contact area and dramatic expansion with changing the conformity seemed to play important roles in scuffing.     

铁谱图像分析技术研究

利用MATLAB的图像处理技术对铁谱磨粒图像进行数字化分析，求解了磨粒图谱的一些形状特征参数，通过对量化的数据进行统计和比较，揭示了铁谱图像的一些基本特性，以及这些特征所代表的一般意义和在铁谱磨粒图像分析过程中应用。同时，提出了铁谱图像进行计算机图像处理的一般过程以及常用的处理方法。     

滚动轴承保持器磨损对轴承失效的影响

针对滚动轴承运行特点,采用XRF技术调查和分析铜、铁及尼龙为主体材料的保持器在脂润滑条件下的磨损,研究保持器磨损与轴承滚动体磨损之间的相关性及对轴承磨损失效过程的影响,并对不同材料保持器所产生的磨损颗粒对轴承及润滑脂的影响进行初步分析和探讨。统计数据分析结果表明,不同结构或材料构成的保持器在脂润滑轴承运转过程中始终存在着一定程度的磨损,且与轴承滚动体的磨损在磨损相对数量上显著相关;高聚物尼龙保持器所形成的磨损颗粒的影响,更多地反映为保持器材料中硬质填料的机械作用,而钢制保持器因其磨损颗粒具有金属活性和催化性,磨损颗粒同时还加速润滑脂的化学氧化过程及对脂稠化剂网状结构的破坏。     

Wear mechanisms in ball-cratering tests with large abrasive particles

Three-body abrasive wear resistance of mild steel and 27%Cr white cast iron was investigated using a ball-cratering test. Glass beads, silica sand, quartz and alumina abrasive particles with sizes larger than 200 μm were used to make slurries. It was found that the wear rates of mild steel increased with sliding time for all abrasive particles tested, while the wear rates of 27%Cr white cast iron were almost constant with sliding time. This increase in the wear rates of mild steel was mainly due to the gradual increase in ball surface roughness with testing time. Abrasive particles with higher angularity caused higher ball surface roughness. Soft mild steel was more affected by this ball surface roughness changes than the hard white cast iron. Generally, three-body rolling wear dominated. The contribution of two-body grooving wear increased when the ball roughness was significant. The morphological features of the wear scars depended on the shape of the abrasive particles and also on the hardness and microstructure of the wear material. Angular particles generated rough surfaces similar to those usually observed in high angle erosion tests. Rounded particles generated smoother surfaces with the middle area of the wear craters having similar morphology to those observed in low angle erosion.     

气泡高干扰在线铁谱视频图像的磨粒快速分割算法研究

针对在线铁谱视频图像气泡高干扰所面临的磨粒分割困难问题,提出一种气泡高干扰在线铁谱视频图像的磨粒快速分割算法。首先运用运动检测的方法确定视频中气泡的位置,并用相邻帧相同位置的图像信息对气泡区域进行处理,再使用双边滤波对处理后的图像进行平滑去噪,实现气泡干扰的初步抑制;最后基于抑制气泡图像的灰度直方图,对每一帧图像选取其自适应的阈值,实现在线铁谱视频图像中磨粒的快速分割。该研究为在线铁谱的磨粒分割与后续对磨粒特征的智能提取和分析奠定了基础。     

重型汽车中桥减速器润滑油中磨损颗粒分析

重型汽车中桥减速器在工作过程中其摩擦副接触表面因相对运动而产生的磨损颗粒进入润滑油中,导致润滑油性能下降;磨损颗粒随润滑油进入摩擦副接触表面,摩擦副磨损加剧。根据重型汽车的运行特点,每隔一定里程数对减速器润滑油进行取样,综合分析在用润滑油中磨损颗粒物的大小、形貌及成分。结果表明：减速器在用润滑油中磨损颗粒主要成分是铁屑和铜屑,磨损颗粒主要来自于球面垫片（铜）及其配副的摩擦以及齿轮副间的摩擦。具体分析磨损颗粒产生过程及形成机制,为重型汽车中桥减速器中运动摩擦副的设计及制造提供理论依据。     

基于磨粒表面信息的磨损表面特征评估

建立了基于磨粒表面信息的磨损表面评估方法。首先选择合理的磨粒和磨损表面特征参数，通过识别磨粒类型，获得磨损过程中具有典型性和代表性的磨粒类型，然后选取这些具有代表性的磨粒类型，得到磨粒的表面特征向量，进而来研究磨损表面和磨粒表面的映射关系，实现基于磨粒表面信息的磨损表面特征评估。实例表明，根据磨粒表面特征评估磨损表面特征是可行的。     

镀镍石墨磁性纳米粒子对ZL109微弧氧化反应过程及膜层耐磨性能影响

为进一步探索微弧氧化反应过程中微弧氧化陶瓷层表面形貌、孔隙率等基本特征的受控机制,创新地提出向微弧氧化电解液中引入磁性粒子,即镀镍石墨磁性纳米粒子,探索磁性添加剂粒子对微弧氧化反应过程及膜层耐磨性能的影响.从膜层表面形貌、横截面形貌、孔隙率、平均孔径、厚度、表面粗糙度、反应能耗及物相组成等方面对微弧氧化反应过程进行了分...     

Metal-on-metal hip simulator study of increased wear particle surface area due to 'severe' patient activity

This study investigated changes in metal-on-metal (MOM) hip wear and wear particle characteristics arising from a more aggressive patient activity level compared with normal walking. The test hypothesis was that 'severe'-gait conditions will change wear, wear particle sizes, and morphology owing to a decline in joint lubrication. Four carbon MOM hip bearings 40 mm high were subjected to normal-walking and fast-jogging simulations in an orbital hip joint simulator with 25 per cent alpha-calf serum as a lubricant. Co-Cr-Mo wear particles were extracted using an enzymatic method, and prolate ellipsoid equations were used to estimate particle volume and surface area. Fast-jogging simulations generated a sevenfold increase in volumetric wear, a 33 per cent increase in mean wear particle size, and a threefold increase in the number of larger (needle) particles compared with walking. This resulted in a twentyfold increase in total wear particle surface area per 10(6) cycles compared with walking, thereby confirming our hypothesis. The clinical significance of this result suggests that highly active MOM patients may exhibit greater ion release than less active patients.