CrC复合镀层钢球对轴承振动性能的影响

应用非平衡磁控溅射技术在6204轴承钢球表面制备出CrC复合镀层,对CrC镀层钢球轴承和无镀层钢球轴承的振动性能进行试验及对比分析。结果表明,CrC镀层钢球轴承明显降低了轴承的振动值,特别是在高速、高载荷工况情况下减振效果尤为显著;提高了轴承振动的平稳性能。     

基于磁控溅射技术的CrCN镀层钢球对轴承温升性能的影响

应用非平衡磁控溅射离子镀技术在6204轴承钢球、45JHJ钢片及单晶硅片的表面制备出CrcN复合镀层,对CrCN复合镀层的表面粗糙度和摩擦学性能进行了测试,并对CrCN复合镀层钢球轴承和无镀层钢球轴承的温升性能进行了试验和对比分析.研究结果表明,制备的CrCN复合镀层具有较低的表面粗糙度(Ra为7.526 nm)和摩擦系数(约为0.11～ 0.12);CrCN复合镀层钢球轴承有良好的温升性能.     

基于自润滑C(Cr,N)镀层钢球轴承的速度性能研究

应用非平衡磁控溅射离子镀技术在6204轴承钢球表面制备出自润滑C(Cr,N)镀层。运用扫描电子显微镜和透射电子显微镜对镀层的微观结构进行了观察分析;测试了镀层的结合强度、硬度、韧性及摩擦特性;用高性能轴承试验台对镀层钢球轴承和无镀层轴承的速度性能及其自润滑性能进行了实验,并对其给予对比分析。研究结果表明,制备的C(Cr,N)镀层具有良好的微观结构和综合的机械性能;与无镀层轴承相比,镀层明显减小了轴承的振动,极大地提高了轴承的高速性能和自润滑性能。     

CrAlTiN镀层在精密铣刀上的应用研究

介绍了通过闭合场非平衡磁控溅射离子镀技术制备出的CrAlTiN超硬纳米梯度复合镀层在铣刀上的应用,试验结果表明,铣刀在离子镀处理之后寿命提高为原来的3倍.采用SEM和TEM分析了镀层铣刀磨损后的表面形貌及无镀层铣刀的失效方式,揭示了镀层提高铣刀寿命的原因.     

柱弧离子镀和非平衡磁控溅射镀制备Ti-N-C黑色硬质膜

采用柱弧离子镀和中频孪生靶非平衡磁控溅射镀膜技术制备了Ti-N-C多层复合黑色硬质膜.采用轮廊仪扫描电子显微镜(SEM)、分光光度计、显微硬度计等手段研究了所得膜层的各项性能.结果表明,两种工艺都可以获得颜色较深的黑色硬质膜,柱弧离子镀制备黑色硬质膜的效率高、力学性能更好;中频孪生靶非平衡磁控溅射制备的黑色硬质膜表面光滑、颜色更深.     

铀表面非平衡磁控溅射离子镀Ti基薄膜的组织结构与腐蚀性能

金属铀的化学性质十分活泼,极易发生氧化腐蚀。本文采用磁过滤多弧离子镀在金属铀表面制备Ti过渡层,然后采用非平衡磁控溅射离子镀技术制备了Ti、TiN单层膜及Ti/TiN多层薄膜,以期改善基体的抗腐蚀性能。采用X射线衍射、极化曲线、盐雾腐蚀试验对镀层的结构、表面形貌、抗腐蚀性能进行了分析。结果表明,采用磁控溅射在金属铀表面制备一层Ti/TiN多层膜后,多层膜界面较清晰,大量的界面可终止柱状晶的生长,细化晶粒,提高镀层的致密性,有效地改善了基体的抗腐蚀性能。     

含钛MoS2合金减摩镀层摩擦学性能研究

应用闭合磁场非平衡磁控溅射离子镀技术,制备了不同Ti含量的MoS2合金减摩镀层,研究了添加元素Ti含量对镀层厚度、硬度、摩擦系数等的影响规律.结果表明MoS2合金减摩镀层的厚度与添加元素Ti溅射靶的输入功率无关,其硬度随Ti含量增加而提高.不同Ti含量的镀层摩擦系数呈现出不同的变化规律.Ball-on-disc 球盘摩...     

非平衡磁控溅射类金刚石薄膜的特性

非平衡磁控溅射(UBMS)结合了普通磁控溅射(MS)和离子束辅助沉积的优势,易于实现离子镀,近年来得到了广泛的应用.采用该技术制备的类金刚石薄膜(DLC)具有许多独特的性质.本文研究了非平衡磁控溅射技术制备DLC薄膜的光学、机械,电学和化学性能.研究表明,非平衡磁控溅射制备的DLC膜具有较宽的光谱透明区,且表面光滑、摩擦系数小、耐磨损、抗化学腐蚀,同时具有较高的电阻率和良好的稳定性.     

碳靶电流对CrCN镀层摩擦系数的影响

采用闭合场非平衡磁控溅射离子镀技术于单晶硅和M2高速钢基片上制备CrCN镀层以研究C靶电流对CrCN镀层摩擦系数的影响,并通过能谱、原子力显微镜、X射线衍射、X射线光电子能谱分析了C元素的存在状态及其对CrCN镀层组织结构的影响规律.结果表明,当碳靶电流Ic从0A增大到1-5A时,镀层摩擦系数从0.75降至0.3,镀层...     

TiAlN和TiCrAlN薄膜的制备和耐磨性能

采用电弧离子镀和非平衡磁控溅射镀膜技术沉积TiAlN,TiCrAlN薄膜和TiCrAlN/TiCrN复合薄膜。采用扫描电镜(SEM)观察薄膜表面形貌和磨痕形貌,X射线衍射(XRD)检测薄膜结构,俄歇电子能谱仪(AES)分析薄膜成分,摩擦磨损试验评价薄膜的耐磨损性能。实验结果表明,采用Ti/TiN复合膜过渡层,可有效提高薄膜与基体的结合性能;采用磁控溅射与电弧离子镀复合技术制备的TiCrAlN/TiCrN薄膜表面较光滑、粗糙度小,与基体结合强度较高,仅产生较轻微的磨粒磨损和疲劳磨损,具有较优的耐磨性能,适合用于刀具表面处理。     

Study of anti-coking property of SiO2/S composite coatings deposited by atmospheric pressure chemical vapor deposition

To alleviate catalytic coking on the inner surfaces of radiant tubes for ethylene production in petrochemical plants, SiO₂/S composite coatings were prepared on the surface of HP40 steel tube using dimethyldisulfide (DMDS) and tetraethylorthosilicate (TEOS) by atmospheric pressure chemical vapor deposition. A comparison of anti-coking property of the coated and uncoated HP40 steel tubes has been made under the same conditions. SiO₂/S composite coatings are compact and have better anti-coking property. The coke on the coated HP40 steel tube is about 22% of that on the uncoated HP40 steel tube, and only small granular coke is deposited on the coated HP40 steel tube. However, the filamentous coke is formed on the uncoated HP40 steel tube. SiO₂/S composite coatings have good thermal stability at cracking temperature by the comparison of Raman spectra before and after coking.     

Einsatz von Hartstoffbeschichtungen bei Spindellagern

Application of hard surface coatings for spindle bearings The demands on modern Machine Tools ascends continuously with the requirements of the production for high quality and short‐time processings. Particularly the increase of the processing‐ and removal times of the last years dues to higher loads of the main spindle bearing. The bearing as a central machine component characterises the performance of the Machine Tool for the cutting process and defines the reliability of the main spindle. The majority of the applicated spindle bearings are ball bearings. A large amount of the spindle fall‐outs is caused by a non adequate or defecitive lubrication and is effected by the tribological properties of the bearing elements. For the reduction of friction and wear nowadays several materials, coatings and lubrication additives are applied. Actual researches focus on the development of hard surface coatings (a‐C:H:W) with a nano structure for the rolling contact of ball bearings to increase their reliability. In this article the test of nano structured hard surface coating systems for the reduction of friction, warming and wear are presented. Thus the coating systems are verificated for the application in spindle bearings by pretesting. According to the evaluation the inner and outer raceway of standard‐hybrid bearings are coated and the adhesion in reference to rotational speed, resistance and wear performance at high acceleration is analysed. Concluding the emergency running properties at dry‐running condition is evaluated to identify the field of application for the coatings.     

钴基合金-碳化钨复合涂层耐磨抗蚀性能研究

采用真空熔烧法制得钴基合金-碳化钨复合涂层.应用盘销式摩擦磨损试验机对不同碳化钨含量的复合涂层和淬火态45#钢进行了磨损试验.借助自设计振动装置,在10%HCl溶液及10%NaOH溶液中进行了室温全浸泡振动腐蚀试验.试验结果表明,复合涂层的耐磨性显著高于淬火钢,且其耐磨性随碳化钨含量的增加而提高,复合涂层在腐蚀液中耐蚀性也远高于45#钢.     

滚动轴承的振动性能退化过程与保持可靠性研究

为了分析滚动轴承的振动性能退化过程与保持可靠性之间的关系,提出一种基于最大熵法和相似度法的滚动轴承振动性能退化模型,并对滚动轴承的退化过程进行评估;然后基于最大熵法和泊松过程建立滚动轴承振动性能保持可靠性模型;最后基于灰关系理论对滚动轴承的性能退化序列和保持可靠性序列进行分析。实验结果表明,所提出的滚动轴承振动性能退化模型能够有效地识别滚动轴承的退化状态,并且滚动轴承振动性能保持可靠性的演变历程与振动性能退化过程之间有明显的灰关系,可信水平均达到80%以上。     

Fatigue life behaviour of TiAlN and TiAlN/CrN coated notched P20 steel specimens

The performance of single layer TiAlN and multilayered TiAlN/CrN physical vapour deposition coatings deposited on AISI P20 steel substrate in affecting overall fatigue resistance of notched specimens was assessed and compared with the performance of the uncoated counterparts. V‐shaped circumferential notches on cylindrical specimens were adopted for fatigue tests. Surface coating characteristics such as hardness, elastic modulus and microstrains were measured and found to be different and often larger than those of the steel substrate. Unlike the un‐notched (smooth) coated specimens, which are known to exhibit large improvements in fatigue life in the high cycle fatigue regime, considerable reductions in fatigue life of the coated notched samples were observed. This was understood to be because of the coating's brittleness, which induces at the notch tip early and frequent fatigue crack initiations, especially in the case of multiple layered coatings. Scanning electron microscope images showed more crack initiation sites in both the coated specimens compared with the uncoated specimen. Also, presence of dimples on the surface confirmed dimple rupture mechanism in the ductile steel substrate in the coated and uncoated specimens.     

Development of composite spherical bearing

Carbon–phenolic woven composite materials are employed in heavy-duty bearings due to their inherent self-lubricating properties and thermal stability. In this work, a composite spherical bearing (CSB) composed of carbon–phenolic composite race and steel ball is developed to solve the seizure of conventional metal–metal spherical bearings for the elevation driving mechanism (EDM) of a future battle tank. In order to eliminate machining and assembling processes of the composite race, the composite race was manufactured with precise compression molding on the ball surface directly. Several self-lubricating particles were embedded to improve the tribological properties of the inner surface of the composite race. Also the compressive strength of the carbon–phenolic composite with interior wrinkles which were induced during the compression molding was measured to verify the applicability of the carbon composite spherical bearing to the future battle tank.     

复合加固方形木柱的抗震性能分析

为了提高方形木柱的承载能力和抗震性能,提升古建木结构的抗震安全性,提出采用内嵌钢筋、外包碳纤维(carbon fiber reinforced polymer, CFRP)布复合加固木柱。通过方形木柱的低周往复荷载试验,研究了不同加固模式、钢筋用量、CFRP布加固量等因素对木柱抗震加固效果的影响;利用有限元软件OpenSees对复合加固方形木柱的抗震性能开展了数值模拟,通过数值模拟结果和试验数据的对比验证了有限元模型的可靠性;分析了轴向荷载、钢筋直径、CFRP布层数等参数对复合加固方形木柱滞回性能、侧向承载能力、延性性能、刚度退化以及耗能能力的影响。分析结果表明,内嵌钢筋可以显著提升方形木柱的侧向承载能力和耗能能力;外包CFRP布能够限制木材横向变形和内嵌钢筋的外凸,提高方形木柱的延性性能,延缓其刚度退化;复合加固能够大幅度提高方形木柱侧向承载力、延性及耗能能力,改善其刚度和强度退化,抗震加固效果显著。     

对称角铺设矩形复合材料叠层板受低速冲击时的应力波传及解层破坏分析

采用碰撞力分段模型和一阶剪切理论分析了给定初始速度的铁球与四边简支的复合材料叠层板中心发生碰撞的动力学行为,包括碰撞力及接触时间的变化规律、叠层板的振动响应、应力波传、表面沉陷等。并根据忽略厚度的界面模型假设及简化的Tsai Wu张量理论对复合材料叠层板的解层破坏进行了计算和分析,并给出了破坏区大小与铁球初始速度的关系。研究表明:碰撞力与铁球的初始速度成正比;复合材料叠层板中应力波传沿固定方向的相速度在各层内相同,拉伸应力波传速度沿纤维总体占优的方向大于其垂直的方向,而剪切应力波传速度则相反。即使在较低的初始碰撞速度下, 复合材料叠层板的解层破坏也很明显,并且破坏区域随初始碰撞速度的增大而不断扩展,其形状也会发生改变。      

水性聚苯胺/叔氟丙烯酸酯复合防腐涂层的制备及性能

为研究水性聚苯胺/叔氟丙烯酸酯（PANI/VFAc）复合涂层对Q235钢防腐蚀性能的影响,首先,以叔碳酸乙烯酯（Veova 10）和甲基丙烯酸十二氟庚酯（DFMA）为功能单体合成了VFAc乳液,并将其与PANI乳液混合后涂刷在Q235钢表面,制备了PANI/VFAc复合涂层;然后,采用TEM和FTIR对VFAc的结构进行了表征,采用XPS和接触角（CA）研究了复合涂层的表面性能,采用电化学方法研究了不同改性丙烯酸酯乳液对复合涂层防腐蚀性能的影响。结果表明:PANI/VFAc复合涂层的水接触角为97.56°,湿附着力等级为0,涂层表现出较好的疏水性;其腐蚀电流密度为8.72×10-8 A·cm-2,电化学阻抗达到106 Ω·cm2。所得结论表明PANI/VFAc复合涂层对Q235钢具有良好的防腐蚀性能。