氧化稀土对NiP化学镀层及其复合镀层耐磨性的影响

讨论了氧化稀土对Ｎｉ Ｐ 化学镀层及其复合镀层在有冲击和振动载荷作用下滑动磨损行为的影响，并采用数学线性回归的方法得到了不同镀层的磨损量与磨损时间之间的关系曲线，计算出不同镀层的相对耐磨性。     

SiC强化镍基纳米复合电刷镀层的干摩擦磨损特性

采用电刷镀技术制备了快速镍和,n-SiC/Ni、n-SiC/Ni-W复合镀层,研究了镀层的干摩擦磨损特性,测定了镀层的显微硬度,采用扫描电子显微镜(SEM)观察分析了镀层磨痕形貌.结果表明:纳米粒子的加入可以显著地提高镀层的耐磨性.纳米复合镀层的磨损机制以磨粒磨损为主,而纯镍镀层以粘着磨损和磨粒磨损为主.     

Ni-P-纳米Al2O3复合镀层耐磨性能研究

本文通过在Ni-P合金化学镀液中加入纳米α-Al2O3颗粒,获得Ni–P–纳米Al2O3复合镀层。采用SEM对Ni–P–Al2O3复合镀层的表面形貌进行分析;采用EDX对复合镀层中的元素进行分析;用显微硬度计测量了不同Al2O3质量分数下镀层的硬度值;通过MM-W1立式万能摩擦磨损试验机对复合镀层的磨损性能进行了评价,并分析了复合镀层的磨损机理。结果表明:纳米Al2O3的加入可以增加镀层的硬度,并能有效地降低摩擦副之间的犁沟效应及摩擦表面发生粘着的面积,从而减少镀层的磨损。     

基于电接触强化的铝合金表面电刷镀镍层改性研究

[目的]对铝合金进行表面处理可提高其硬度和耐磨性,拓宽铝合金材料在机械零件方面的应用。[方法]采用电刷镀技术在1060铝合金表面制备Ni镀层,再通过电接触强化技术对Ni镀层进行改性。采用扫描电子显微镜和维氏硬度计考察了Ni镀层电接触强化前后的微观组织和显微硬度。通过摩擦磨损试验对比了1016铝合金及Ni镀层电接触强化前后的耐磨性。[结果]经电接触强化后,Ni镀层内部的裂纹及孔洞类缺陷减少,晶粒间隙减小,致密性提高,显微硬度增大到524.4～560.3 HV0.1范围内。1016铝合金在摩擦磨损试验后存在较深的犁沟和剥落,耐磨性较差。Ni镀层的耐磨性优于1016铝合金,但在摩擦过程中会发生剥落。经电接触强化的Ni镀层在摩擦过程中摩擦因数平稳,表面只是轻微擦伤,耐磨性最佳。[结论]结合电刷镀镍和电接触强化技术可显著提高铝合金的表面性能。     

表面强化镀层对高速轴承腔密封端面变形及摩擦磨损影响分析

为了揭示表面强化镀层有效改善高速轴承腔油润滑机械密封的耐磨性和稳定性机制，本文采用数值分析与试验相结合的方法，对端面镀Cr强化机械密封展开端面变形及摩擦磨损性能分析。通过热力耦合数值模拟分析了不同厚度Cr镀层摩擦副对端面温升、变形的影响，使用摩擦磨损试验机研究了相应摩擦副对摩擦系数和磨损量的影响，采用高速密封样机测试了端面温升、密封效果，探究了强化镀层密封端面摩擦磨损强化机理。结果表明：热力耦合作用下高速密封端面产生发散型变形，端面磨损以磨粒磨损为主，端面外侧出现局部黏着磨损；对比无镀层密封端面，Cr镀层端面变形小，温升低，更容易形成稳定的摩擦转移膜；适当增加Cr强化层厚度有利于降低端面温升，提高密封稳定性，高速轻载工况下较优镀层厚度约为0.15mm。本文研究结果可以为高速轴承腔油润滑机械密封材料选配和结构优化提供借鉴。     

浅谈摩擦与磨损

介绍了摩擦与磨损的定义;摩擦与磨损产生的原因、危害性及分类方法;减摩性及耐磨性的表征参数、测量方法;磨损的分类方法等.最后,以电镀及复合电镀为例,简单介绍了在表面处理技术中制备减摩镀层和耐磨镀层的优越性.     

电刷镀高锡铜锡合金镀层的热处理及摩擦性能研究

基于碱性焦磷酸盐体系,在45钢基体上采用电刷镀技术制备了锡质量分数分别为52.6%、61.4%和70.0%的高锡铜锡合金镀层。考察了热处理对镀层组织和显微硬度的影响,以及镀层的摩擦性能。结果表明:经过180°C热处理之后,镀层发生再结晶现象,晶粒粗化,硬度下降,与此同时镀层晶化程度提高,出现Cu3Sn晶化相。在干摩擦条件下,热处理前后高锡镀层的摩擦因数在0.50~0.70之间,未发生明显变化,但磨痕宽度和磨损体积有不同幅度的下降,其中锡含量为61.4%的镀层的摩擦性能最佳。进一步研究其分别在NF2、E02和澳力丹微乳化液3种润滑条件下的摩擦性能,发现热处理前后镀层均只发生了轻微的磨粒磨损,摩擦性能未发生明显变化,摩擦因数在0.03~0.15之间,磨痕宽度在40.0~60.0μm之间,但热处理后磨痕的犁沟宽度变窄,犁沟数量减少,说明热处理后镀层脱落的概率减小,耐磨性增强。     

汽车活塞环表面电镀Ni-SiC复合镀层

因所处的工作环境较严酷而造成的异常磨损,已经成为汽车活塞环的主要失效形式。为了增强活塞环的耐磨性进而延长其使用寿命,在其表面电镀Ni-SiC复合镀层。结果表明:电镀活塞环表面较平整,显微结构致密;磨损失重量仅为5.8mg,比未镀活塞环的降低近33%,表现出较好的耐磨性;并且经适度热处理后,耐磨性有所增强。复合镀层起到表面改性作用,是电镀活塞环耐磨性增强的主要原因所在。     

复合刷镀层的磨损机理

本文针对复合刷镀层中复合微粒含量与分布不同，对复合镀层的抗磨、减磨性能及其机理进行试验分析。试验证明，复合镀层的耐磨性依赖于所加入的微粒的形状、体积含量及基质的磨损特性，而且晶体结构、硬度等对复合镀层的耐磨性也有重要的影响。     

刷镀工艺在铝合金压铸件磨损后修复中的应用研究

鉴于铝合金刷镀层结合力差,易产生裂纹及剥落现象,本文提出了一种新的铝及其合金刷镀工艺,阐述了各工艺步骤的配方及操作条件,过层采用高堆积大铜,工作层为快速刷镀镍,根据GB2933－86测试镀层结合力及耐磨性,结果表明,该工艺可提高刷镀层的结合力和耐磨性,延长零件使用寿命,适用于铝合金压铸件磨损后的修复。     

Ni-P复合镀层摩擦磨损性能的研究

采用化学复合镀在碳钢基体上共沉积（Ni-P）-SiC和（Ni-P）-PTFE两种复合镀层,重点研究了两种复合镀层在相同对磨条件下的摩擦磨损性能及磨损机理表现形式,并与化学镀镍磷层进行对比。结果表明,本实验条件下所制备的（Ni-P）-SiC和（Ni-P）-PTFE两类复合镀层分别具有优异的耐磨和减磨性能,均能对所镀覆基体材料起到良好的保护作用;对磨实验过程中主要出现磨料磨损、粘着磨损和氧化磨损三种磨损方式,而且磨损方式不同,镀层的摩擦磨损性能表现也不尽相同。     

镁合金(Ni-P)-SiC纳米颗粒化学复合镀层硬度及耐磨性的研究

研究了镁合金(Ni-P)-SiC纳米颗粒化学复合镀层的制备,并对复合镀层的性能进行测试,揭示出SiC纳米颗粒和表面活性剂对镀层硬度及耐磨性的影响规律。     

气力输送中影响弯管磨损的因素及预防措施

概述了气力输送中弯管磨损的机理,详细阐述了气力输送过程中物料的物性、输送气速、料气比、弯管的结构及形状等影响弯管磨损的主要因素对气力输送过程中对弯管磨损的影响,并从弯管材料和结构两方面论述了减少弯管磨损的预防措施.     

Wear behavior of silicone rubber/carbon black coatings on 6061 aluminum alloy surfaces

In this paper, the effects of structural and process variables on wear resistance of silicone rubber/carbon black coatings on 6061 aluminum alloy surfaces are studied. Testing parameters have been optimized for maximum wear resistance based on taguchi orthogonal design with six important parameters, viz. polydimethylsiloxane (PDMS) molecular weight, oxime/OH ratio, catalyst weight percent, pigment weight percent, surface preparation method and adhesion promoter type. The analysis of variance showed that the wear resistance strongly depends on oxime/OH ratio and catalyst weight percent. PDMS molecular weight and pigment weight percent also have intermediate effects. Neither the surface preparation method nor adhesion promoter type had any effects on wear resistance in this study. The optimum sample was prepared according to the best levels of each factor and the wear resistance in optimum conditions was reasonably in agreement with the experimental data. Scanning electron microscopy analysis of wear surface and debris showed two mechanisms: cohesive wear with fatigue mechanism and interfacial wear with adhesion mechanism.     

纳米TiO2/PTFE复合材料的干摩擦磨损性能

利用磨损试验机、扫描电子显微镜等方法研究了表面处理与未处理纳米TiO2(质量分数为6％)填充聚四氟乙烯(PTFE)复合材料的干摩擦性能。结果表明，纳米TiO2能明显提高：PTFE耐磨性并改变其磨屑形成机理。表面处理纳米TiO2在PTFE中能较均匀分散。纳米TiO2填充PTFE复合材料的摩擦系数比PTFE稍大，纳米TiO2表面处理与否对PTFE复合材料的摩擦系数影响不大，但表面处理纳米TiO2填充聚四氟乙烯耐磨性比PTFE有显著提高，表面处理与表面未处理纳米TiO2填充PTFE复合材料的耐磨性比PTFE可分别提高7倍和3倍左右。导致PTFE磨损的重要机理是粘着磨损。     

Wear resistance of alumina-coated oil casing steel N80 via MAO with rare earth additive

The wear resistance of oil casing steel N80 was improved by packing its aluminide prelayer at a relative low temperature. Then, an alumina coating was obtained through microarc oxidation (MAO), in which different La₂O₃ contents were added into the electrolyte. The chemical compositions and microstructures of the as-prepared coatings were characterized through scanning electron microscopy (SEM) equipped with energy-dispersive spectrometer (EDS). The wear resistance of the coated oil casing steel N80 under simulated oil and gas well condition was also investigated. With 1.5 g/L La₂O₃ addition, a denser alumina coating containing α-Al₂O₃ and γ-Al₂O₃ with 1750 HV microhardness value was obtained. Under the simulated oil and gas well wear condition, the oil casing steel N80 with an alumina ceramic coating, which was prepared by adding 1.5 g/L La₂O₃ in the electrolyte, showed a stable friction coefficient and low weight loss. Among the steel samples in this study, the oil casing steel N80 with an alumina ceramic coating exhibited the least wear debris and the shallowest groove. The influence mechanism of rare earth on the microstructure of the ceramic coating via MAO was discussed in detail.     

激光强化电刷镀Ni镀层耐磨性研究

制备了激光强化电刷镀Ni镀层,研究了其硬度和耐磨性,分析了激光强化电刷镀Ni镀层耐磨性增加的原因.实验结果表明:当P激光为400 W时,激光强化电刷镀Ni镀层的硬度比普通Ni刷镀层提高约250 HV,相对耐磨性是1.56倍,晶粒细化是镀层硬度和耐磨性增强的主要原因.     

传统陶瓷耐磨性能评价方法

本文介绍了现有的传统陶瓷产品耐磨性能测试方法与标准,分析了这些测试方法用于测试传统陶瓷耐磨性能的可行性和不足之处,提出可以统一有釉砖与无釉砖耐磨性能测试方法与标准。     

Investigation of tribological properties of micro-arc oxidation ceramic coating on Mg alloy under dry sliding condition

To enhance wear resistance of Mg alloy, micro-arc oxidation (MAO) ceramic coatings on Mg substrate were prepared in silicate electrolyte under various currents. It was found that the surface roughness and thickness of MAO coating were increased with the increase of current. The dry tribological tests showed that the friction coefficient and wear resistance of thicker coatings (obtained under currents of 3?A and 4?A) were much higher than that of Mg alloy and the thin coating (obtained under current of 2?A), meanwhile the lifetime of the coating obtained under 4?A was longer than the other coatings under higher load. The wear type of thin MAO coating was slight abrasive wear under low load, whereas translated to severe adhesive wear under high load. While the main wear mechanism of thick MAO coating was slight abrasive wear or scratch under the given test condition, which was attributed to the thick intermediate layer improved load support for the soft substrate. The tribological study indicated that the MAO coating obtained under 4?A current had better wear resistance and life time due to its compact microstructure and thickness.     

Ni-P-PTFE自润滑镀层的耐磨性能及其增强机理研究

采用化学复合镀技术将纳米聚四氟乙烯(PTFE)微粒沉积到化学镀Ni-P镀层中。扫描电镜(SEM)表明:镀层内PTFE微粒分散均匀,与Ni-P镀层结合紧密。摩擦磨损实验表明:在100N作用下,Ni-P-PTFE镀层的摩擦因数约为0.03,具有良好的摩擦学性能。热处理后的摩擦磨损实验表明:经热处理后,镀层仍具有较低的摩擦因数和良好的耐磨性能。