Ni-P/nano-Al_2O_3复合镀层的制备及性能

以汽车模具配件—导柱常用的20Cr钢为基材,在其表面制备Ni-P/nano-Al_2O_3复合镀层及普通Ni-P镀层。对Ni-P/nano-Al_2O_3复合镀层的微观形貌、晶相结构、显微硬度和摩擦磨损性能进行了测试与分析,并与Ni-P镀层和基材进行了对比。结果表明,Ni-P/nano-Al_2O_3复合镀层的晶粒细小,结构更加致密,显微硬度平均值可达到436.4 HV,高于Ni-P镀层的357.3 HV和基材的190HV;与Ni-P镀层相比,Ni-P/nano-Al_2O_3复合镀层能更有效地改善基材的摩擦磨损性能。NanoAl_2O_3颗粒复合量对Ni-P/nano-Al_2O_3复合镀层的显微硬度和摩擦磨损质量损失率有一定影响,增加颗粒复合量可以提高复合镀层的显微硬度,改善其摩擦磨损性能。     

Ni-P-SiC化学复合镀层耐磨性与显微硬度的研究

介绍了一种Ni-P-SiC化学复合镀工艺。研究了热处理温度与时间、SiC粒径与共析量时复合镀层显微硬度和耐磨性的影响。经400℃以上热处理1h后，该复合镀层比常用铬镀层及其它Ni-P基化学复合镀层硬度大、耐磨性好。     

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。     

可溶性阳极电刷镀纳晶Ni-P-SiC复合镀层的耐磨损性能

采用可溶性镍阳极电刷镀方法,在铜片上制备了Ni-P纳晶镀层和Ni-P-SiC复合镀层,镀层表面平整、致密、无裂纹.纳米颗粒的加入没有改变镀层的纳米晶结构,对镀层磷含量影响不大.硬度测试和摩擦磨损试验表明:纳米SiC的加入起到细晶强化和弥散强化作用,可以提高镀层的硬度和耐磨性能:添加纳米颗粒后镀层磨损方式由黏着磨损转变为磨粒磨损.     

化学镀制备高耐蚀耐磨Ni-P-SiC复合镀层

研究了Ni-P-SiC复合镀层的制备工艺和性能以及SiC含量对镀层性能的影响。采用Taber试验机对Ni-P-SiC复合镀层的磨损性能进行了测试,并用VHX-100型三维视频显微镜对磨损形貌进行了观察,分析了复合镀层的磨损机理。结果表明:SiC颗粒的加入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。采用电化学实验等手段研究了Ni-P-SiC复合镀层的耐蚀性能。当复合镀层均匀一致,能起到一个良好的屏蔽作用时,耐蚀性十分优异;而镀层缺陷的存在将导致耐蚀性能降低。     

润滑油添加剂羟基硅酸镁/二硫化钼含量对镀铬钢球-灰铸铁摩擦副摩擦学行为的影响

[目的]内燃机活塞环服役环境恶劣,需要良好的润滑条件来改善其磨损情况。[方法]在2Cr13钢球上电镀硬铬,分析了硬铬镀层的微观形貌、显微硬度和厚度。以镀铬钢球和灰铸铁作为摩擦副进行摩擦磨损试验,以模拟活塞环的服役环境。研究了添加剂羟基硅酸镁/二硫化钼(MSH/MoS₂)含量不同的润滑油中镀铬层与灰铸铁之间的摩擦学行为。[结果]镀铬层具有微裂纹,显微硬度高达(1 013.7±32.4) HV,平均厚度达(84.2±3.6)μm。润滑油中MSH/MoS₂纳米颗粒的质量分数为1.0%时,对镀铬钢球-灰铸铁摩擦副的减摩抗磨效果最显著,相较于采用纯润滑油时,镀铬钢球的平均摩擦因数和磨斑直径分别下降了28.2%和24.2%,灰铸铁的磨损率也下降了23.1%。[结论]润滑油中添加适量MSH/MoS₂纳米颗粒对镀铬钢球-灰铸铁摩擦副起到很好的减摩抗磨效果。     

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。     

放电等离子烧结氮化硅陶瓷刀具材料的摩擦磨损性能

研究了放电等离子烧结氮化硅陶瓷刀具材料(91wt％ α-Si3N4 +5wt％ MgSiN2 +3wt％ Y2O3 +1wt％ CeO2)在干滑动条件下分别与氮化硅陶瓷和轴承钢GCr15的摩擦磨损性能.结果 表明:Si3N4/Si3N4滑动副的摩擦系数和磨损率随着滑动速度的增加而减小,且不同滑动速度下的磨损表面均有明显的犁削特征和剥落,其磨损形式主要为磨粒磨损;Si3N4/GCr15滑动副的摩擦系数和磨损率随着负载的增加先减小后增大,其磨损机理为氧化磨损和粘着磨损.由于氮化硅球的高硬度和轴承钢的相对低硬度,相同条件下Si3N4/Si3N4滑动副的磨损率均大于Si3N4/GCr15.     

活塞表面Ni-P-SiC复合镀层的电沉积及性能表征

从替代电镀铬的绿色表面处理技术出发,通过复合电沉积技术在活塞表面制备Ni-P-SiC复合镀层.电沉积前,对纳米SiC颗粒进行酸洗改性.利用扫描电子显微镜(SEM)、能谱分析(EDS)和显微硬度计研究了阴极电流密度对复合镀层性能的影响,采用往复式摩擦磨损试验测试其耐磨性,并用三维轮廓仪对其磨损率进行表征.结果表明:碳化硅...     

化学沉积Ni—P—SiC镀层

本文研究了化学沉积Ni-P-SiC复合镀层的工艺与性能.结果表明,SiC粒子的复合,显著地增加了Ni-P合金镀层的硬度和耐磨损性能.     

机械泵旋片基材表面化学镀Ni-P/PTFE复合镀层

在机械泵旋片用45Mn钢板表面制备了化学镀Ni-P/PTFE复合镀层,并研究了PTFE的质量浓度对化学镀Ni-P/PTFE复合镀层的沉积速率、耐磨性、耐蚀性及表面形貌的影响。结果表明:适当增加PTFE的质量浓度,有利于加快沉积速率,提高化学镀Ni-P/PTFE复合镀层的耐磨性和耐蚀性。化学镀Ni-P/PTFE复合镀层表面呈胞状形貌,PTFE均匀分布在表面。当PTFE的质量浓度为8 g/L时,化学镀Ni-P/PTFE复合镀层具有最佳的耐磨性和耐蚀性。     

( Ni-P)-Al2O3纳米微粒复合镀层硬度和耐磨性测试

为了改进钢材表面性能,采用复合化学镀技术制备( Ni-P) -Al2O3纳米微粒复合镀层,由于纳米微粒独特的物理化学特性致使使得到的复合镀层具有多种优良性能.通过Ni-P合金镀层、(Ni-P) -Al2O3纳米微粒复合镀层和热处理后的(Ni-P) -Al2O3纳米微粒复合镀层硬度和耐磨性能测试,得出(Ni-P)-Al2...     

Wear resistance and hardness properties of TiB2– Fe coating developed on AISI 1020 steel by tungsten inert gas (TIG) cladding

The present work is attempted to improve the microhardness and wear properties of AISI 1020 steel by depositing TiB₂–Fe composite coating using tungsten inert gas (TIG) cladding. In this study, different compositions of TiB₂–Fe paste form were preplaced on the substrate plates and then TIG heat input was applied to deposit hard composite coating layer. The main objective of the present work was to explore the influence of TIG input current as well as iron content on the microstructure and surface properties of deposited coatings. Microhardness, microstructural and phase characterization of the coating have been done by the Vickers microhardness tester, scanning electron microscope (SEM), Energy dispersive spectroscopy (EDS) and X-ray diffractrometer (XRD). The results showed that the microhardness of the TiB₂–Fe coating was strongly influenced by the composition of the coating materials as well as the TIG processing current. The microhardness increases with decreasing Fe contents in the coating materials with constant processing current (90 A) as well as it also increases with decreasing processing current with the fixed composition of coating materials (80TiB₂–20Fe). The maximum average microhardness found was 3082 HV_0.1 for the coating of 100TiB₂–0Fe composition ratio and 90 A processing current which was about 18 times higher than that of the substrate average microhardness value (163 HV_0.1). Average wear rate evaluated by considering weight loss of the TIG cladded samples using pin on disc tribometer by the sliding distance of 864 m and 20 N normal loads. The wear results also showed that the coating contains 100 wt% of TiB₂ (0 wt% of Fe) exhibited lower rate of wear 6.74 × 10^?8 g/Nm which is about 24 times lower as compared to AISI 1020 mild steel wear rate (166.31 × 10^?8 g/Nm).     

Tribological behavior of three‐dimensional braided carbon fiber reinforced polyetheretherketone composites

Three‐dimensional (3D) braided carbon fiber reinforced polyetheretherketone (denoted as CF_3D/PEEK) composites with various fiber volume fractions were prepared via hybrid woven plus vacuum heat‐pressing technology and their tribological behaviors against steel counterpart with different normal loads at dry sliding were investigated. Contrast tribological tests with different lubricants (deionized water and sea water) and counterparts made from different materials (epoxy resin, PEEK) were also conducted. The results showed that the incorporation of 3D braided carbon fiber can greatly improve the tribological properties of PEEK over a certain range of carbon fiber volume fraction (V_f) and an optimum fiber loading of ∼54% exists. The friction coefficient of the CF_3D/PEEK composites decreased from 0.195 to 0.173, while the specific wear rate increased from 1.48 × 10⁻⁷ to 1.78 × 10⁻⁷ mm³ Nm⁻¹ with the normal load increasing from 50 to 150 N. Abrasive mechanism was dominated when the composites sliding with GCr15 steel counterpart under dry and aqueous lubrication conditions. Deionized water and sea water lubricants both significantly reduced the wear of the CF_3D/PEEK composites. When sliding with neat PEEK counterpart, the CF_3D/PEEK composites possess lower friction coefficient than those against epoxy resin and GCr15 steel counterparts. In general, CF_3D/PEEK composites possess excellent tribological properties and comprehensive mechanical performance, which makes it become a potential candidate for special heat‐resisting tribological components. POLYM. COMPOS., 36:2174–2183, 2015. © 2014 Society of Plastics Engineers     

Tribological application of carbon nanotubes in a metal-based composite coating and composites

Ni-P-carbon nanotube (CNT) composite coating and carbon nanotube/copper matrix composites were prepared by electroless plating and powder metallurgy techniques, respectively. The effects of CNTs on the tribological properties of these composites were evaluated. The results demonstrated that the Ni-P-CNT electroless composite coating exhibited higher wear resistance and lower friction coefficient than Ni-P-SiC and Ni-P-graphite composite coatings. After annealing at 673 K for 2 h, the wear resistance of the Ni-P-CNT composite coating was improved. Carbon nanotube/copper matrix composites revealed a lower wear rate and friction coefficient compared with pure copper, and their wear rates and friction coefficients showed a decreasing trend with increasing volume fraction of CNTs within the range from 0 to 12 vol.% due to the effects of the reinforcement and reduced friction of CNTs. The favorable effects of CNTs on the tribological properties are attributed to improved mechanical properties and unique topological structure of the hollow nanotubes.     

Ni-P施镀时间对化学复合镀Ni-P/Ni-P-PTFE双镀层性能的影响

采用中磷和高磷两种镀液在30CrMn合金钢基体上依次进行化学镀得到Ni-P/Ni-PPTFE双镀层。研究了Ni-P施镀时间对化学复合镀Ni-P/Ni-P-PTFE双镀层性能的影响。结果表明:随着Ni-P施镀时间的延长,双层镀的表面形貌更加致密、均匀,镀速加快,硬度提高;双镀层在3.5%的NaCl溶液中的自腐蚀电位先正移后负移,自腐蚀电流密度先减小后增大;当Ni-P施镀时间为60min时,双镀层的耐蚀性最佳。     

Tribological behavior of the polyamide composite coating filled with different fillers under dry sliding

The polyamide (PA) composite coating filled with the particles of microsized MoS₂, microsized graphite, and nano‐Al₂O₃, respectively, were prepared by flame spraying. The friction and wear characteristics of the PA coating and composite coating filled with the varied content of filler under dry sliding against stainless steel were comparatively investigated using a block‐ring tester. The morphologies of the worn surfaces and transfer films on the counterpart steel ring were observed on a scanning electron microscope. The result showed that the addition of fillers to the composite coatings changed significantly the friction coefficient and wear rate of the coatings. The composite coatings filled with a low level content of fillers showed lower wear rate than did pure PA coating under dry sliding; especially the MoS₂/PA composite coating had the lowest wear rate among these composite coatings. The composite coatings with a high level content of fillers had higher wear rate than did pure PA coating, except of the Al₂O₃/PA composite coating. The bonding strengths between the polymer matrix and fillers changed with the content of the fillers, which accounted for the differences in the tribological properties of the composite coatings filled with the varied content fillers. On the other hand, the difference in the friction and wear behaviors of the composite coatings and pure coating were attributed to the difference in their worn surface morphologies and transfer film characteristics. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

聚乙烯亚胺对Si3N4纳米微粒复合刷镀的影响

研究了聚乙烯亚胺对刷镀(Ni-P)-Si3N4纳米微粒复合镀液中Si3N4纳米微粒的分散性、刷镀层性能及结构的影响,并确定了聚乙烯亚胺在复合刷镀液中的最佳含量。结果表明,聚乙烯亚胺能有效阻止复合刷镀液中颗粒的絮凝、团聚,其用量对复合刷镀层中Si3N4含量、刷镀层硬度及耐磨性能有显著的影响。当其质量浓度为0.8 g/L时,获得了微粒均匀分散,稳定悬浮的复合刷镀液,复合刷镀层微观表面结构致密,微粒分布均匀,磨损量最小,显微硬度最大。     

镍-磷-硫酸钡化学复合镀层的研制

在由硫酸镍31g/L、次磷酸钠22g/L、乙醇酸30g/L、乙酸钠13g/L、二甲胺0.8g/L、全氟乙基碘化铵0.1g/L及重晶石(即硫酸钡)0～25g/L组成的稳定镀液中,采用化学镀的方法在低碳钢上制备了Ni-P-BaSO4复合镀层.其表面形貌采用扫描电镜进行分析,耐蚀性以动电位极化及电化学阻抗谱测试.镍-磷合金基...