不同纳米氧化铝含量Ni-P-Al_2O_3化学镀层的高温磨损性能

采用化学镀技术制备不同纳米氧化铝含量的Ni-P-Al2O3复合镀层,并利用扫描电子显微镜(SEM)、X射线能谱仪(EDS)和X射线衍射仪(XRD)对镀层的表面形貌、化学成分及微观结构进行表征,考察镀层在600℃下的高温氧化性能,并采用高温摩擦磨损试验机对镀层在200℃和600℃下的摩擦磨损性能进行测试,分析其磨损机理。结果表明:纳米氧化铝的加入可有效提高镀层的高温耐磨性能和抗高温氧化性能。随着镀液中纳米Al2O3用量的增加,镀层的氧化质量增加,摩擦因数先减少后增加,镀层的磨损机理发生变化。镀液中纳米Al2O3用量为3 g/L时,镀层具有优异的抗高温氧化性能、较低的摩擦因数和较低的磨损率。复合镀层在较高温度磨损过程中呈现出较高的磨损率和较低的摩擦因数。     

纳米Al2O3颗粒含量对Ni-Co基纳米复合电刷镀层的组织和性能影响

采用电刷镀技术制备了不同Al2O3颗粒含量的合金纳米复合电刷镀层,采用扫描电镜、硬度测试仪和摩擦磨损试验机测试了纳米Al2O3颗粒含量对镀层的组织和性能的影响。结果表明,随着镀液中纳米Al2O3颗粒含量的增加,电刷镀层沉积速度降低、表面形貌平整,显微硬度先提高而后减低,磨痕深度先减小后增大,摩擦系数先减小后增大。当镀液中纳米Al2O3含量为20g/L时,镀层具有最优的组织和性能。     

结晶器铜板表面耐磨纳米复合镀层的制备及性能

目的提高连铸坯质量,延长结晶器的服役时间,节约铜资源。方法采用纳米复合镀技术在结晶器铜板表面制备了Ni/Al_2O_3纳米复合镀层,并通过扫描电镜(SEM)观察了复合镀层表面形貌。采用单因素变量法研究了镀液中纳米Al_2O_3添加量、阴极电流密度及镀液温度等对纳米复合镀层显微硬度的影响。对结晶器铜板表面的纯Ni镀层和纳米复合镀层进行了摩擦磨损实验。结果在结晶器铜板表面制备出了高硬度、耐磨损的纳米复合镀层。随着镀液中纳米颗粒添加量的增加,镀层的硬度先升高后降低,且当纳米颗粒添加量为40 g/L时,复合镀层的显微硬度达到最大值384HV。因镀液中纳米颗粒的存在,随着电流密度和镀液温度的变化,纳米复合镀层的硬度变化不大。在相同的摩擦磨损条件下,纳米复合镀层和纯Ni镀层的摩擦系数分别约为0.41和0.7,纳米复合镀层的磨损量约为纯Ni镀层的1/2。结论在Ni基镀层中加入纳米Al_2O_3材料,能显著地提高复合镀层的硬度、耐磨损性能。     

滑动速度对纳米颗粒复合镀层摩擦性能的影响

采用电刷镀技术在45钢表面制备了纳米Al2O3颗粒复合镀层,并且在球-盘式肇擦磨损试验机上对比研究了纳米颗粒复合镀层与普通快速镍镀层在含污染物油润滑条件下的摩擦磨损性能。结果表明纳米颗粒复合镀层的摩擦系数和磨损量均小于快速镍镀层。随滑动速度增加,两种镀层磨损量都先减少后增加,但纳米颗粒复合镀层磨损量增加的幅度小于快速镀镍层c两种镀层的磨损机理均为磨粒磨损和粘着磨损。由于纳米颗粒的强化作用,复合镀层的耐磨性优于快速镀镍层。     

Ni-P-SiO2(纳米)化学复合镀研究

通过Ni-P化学镀及Ni-P-SiO2(微米)、Ni-P-SiO2(纳米)化学复合镀探讨纳米SiO2颗粒对镀速及镀层性能的影响。结果表明：添加适量的SiO2纳米粒子于镀液中，使镀速上升，所得镀层硬度、耐磨性等性能相对于Ni-P镀层及微米颗粒复合镀层都有显著地提高。     

纳米Al_2O_3颗粒含量对Ni-Co基纳米复合电刷镀层组织和性能的影响（英文）

采用电刷镀技术制备了不同Al_2O_3颗粒含量的合金纳米复合电刷镀层,使用扫描电镜、硬度测试仪和摩擦磨损试验机测试了镀液中纳米Al_2O_3颗粒含量对镀层的沉积速度、纳米颗粒含量、硬度和摩擦学性能的影响。结果表明,随着镀液中纳米Al_2O_3颗粒含量的增加,电刷镀层沉积速度降低、表面形貌平整,显微硬度先提高而后降低,磨痕深度和摩擦系数先减小后增大。当镀液中纳米Al_2O_3含量为20 g/L时,镀层具有最优的组织和性能。     

纳米Al2O3颗粒含量对复合镀层组织和滑动磨损行为的影响

采用电刷镀技术在45钢表面制备了纳米Al2O3颗粒增强镍基复合镀层，研究了纳米Al2O3颗粒在镀液中的含量对镀层的组织、力学性能和摩擦学性能的影响，并分析探讨了影响机理。结果表明，随着镀液中纳米Al2O3颗粒含量的增加，复合镀层的组织趋于细化，在含量为20g／L时复合镀层的硬度和耐磨性出现极值，其磨损机制也随之发生改变，这与纳米Al2O3颗粒在复合镀层中的含量和分布状态密切相关。     

AZ91HP镁合金电沉积Ni-SiO_2纳米复合镀层的显微结构与耐磨性(英文)

以AZ91HP镁合金为研究对象,以纳米氧化硅为第二相粒子,通过纳米复合电沉积法制备AZ91HP镁合金Ni-SiO2纳米复合镀层。利用扫描电镜观察纳米复合镀层的显微形貌与微观结构,利用显微硬度计测定纳米复合镀层显微硬度,利用M200摩擦磨损试验机测试纳米复合镀层的耐磨性能。结果表明:在AZ91HP镁合金表面获得了结晶均匀、结构致密的Ni-SiO2纳米复合镀层;纳米复合镀层剖面形貌显示纳米复合镀层与镁合金基体结合良好;镀液中纳米颗粒含量为10g/L时,AZ91HP镁合金表面电沉积Ni-SiO2纳米复合镀层的显微硬度最高,最高达HV367;摩擦磨损试验表明纳米复合镀层与镀镍层、镁合金基体相比,耐磨性明显提高,这是由于纳米颗粒的细晶强化和弥散强化所致;纳米复合镀层的磨损机制主要是磨粒磨损,镁合金基体磨损机制为粘着磨损,镀镍层磨损机制为剥层磨损。     

电沉积Ni-P/纳米Al_2O_3复合镀层的摩擦磨损与耐铝液侵蚀性能

研究电沉积Ni-P/纳米Al2O3复合镀层的干摩擦磨损性能和耐铝液侵蚀性能,采用扫描电镜(SEM)观察Ni-P/纳米Al2O3复合镀层的磨损表面形貌以及铝与Ni-P/纳米Al2O3复合镀层的界面结构。结果表明:Ni-P/纳米Al2O3复合镀层(镀态)与淬火45钢对摩时的摩擦因数为0.45～0.55,磨损表现为疲劳剥落;经400℃热处理后,Ni-P/纳米Al2O3复合镀层与淬火45钢对摩的摩擦因数为0.20～0.24,磨损机理表现为轻微粘着和磨蚀;铝液在Ni-P/纳米Al2O3复合镀层表面的润湿角为109,Ni-P/纳米Al2O3复合镀层具有良好的耐铝液侵蚀性能。     

不同h-BN含量Ni-P-WS2-BN化学镀层的组织结构及磨损性能

目的 通过化学镀共沉积技术在Ni-P-WS2镀层中引入六方氮化硼(h-BN)纳米粉末,以进一步提升其硬度和耐磨性,改善其摩擦学性能。方法 将六方氮化硼(h-BN)纳米粉末与二硫化钨(WS2)纳米粉末共沉积制备Ni-P-WS2-BN复合镀层,并对其进行400 ℃×1 h的惰性气氛热处理。采用扫描电镜、X射线衍射仪、摩擦磨损试验机等对镀层的化学成分、组织结构及摩擦学性能进行表征,考察h-BN用量及热处理对复合镀层的影响。结果 随着镀液中h-BN用量的增加,镀层中h-BN含量持续上升,镀层的表面粗糙程度先升高、后降低,胞块结构有致密化倾向,硬度由321HV0.1上升至522HV0.1,磨损率从1.82×10^–13 m³/(N.m)降至0.95×10^–13 m³/(N.m),平均摩擦因数介于1.61~2.00,且呈先降后升的趋势(h-BN用量为3.0 g/L时达到最小值)。经热处理后,镀层硬度可达457~822HV0.1,磨损率从1.24×10^–13 m³/(N.m)降至0.31×10^–13 m³/(N.m),平均摩擦因数降至0.93~1.29。复合镀层的磨损以磨粒磨损机制为主。结论 h-BN粉末的共沉积和400 ℃退火处理可显著提高复合镀层的硬度和耐磨性,大幅度降低摩擦因数和磨损率,改善复合镀层的综合性能。     

喷射电沉积技术制备Co-Cr_3C_2复合镀层的工艺优化

为提高微米级硬质陶瓷颗粒在金属基复合镀层的含量,制备性能优异的防护性镀层,采用喷射电沉积的方法在直流电压下制备了Co-Cr_3C_2复合镀层,利用控制变量法探讨了电流密度、固体颗粒用量、镀液流量以及喷枪移动速度等对镀层中颗粒含量及镀层性能的影响,并分析了各因素的影响机理。同时,分别采用能谱仪、显微硬度计和摩擦磨损试验机对复合镀层的成分、硬度和摩擦因数进行分析,最终确定了制备该复合镀层的较优工艺参数。结果显示:喷头移动速度对颗粒复合量的影响最为显著;颗粒复合量越大,复合镀层硬度越高、摩擦因数越低;在较优工艺参数下制备的Co-Cr_3C_2复合镀层的Cr_3C_2颗粒含量高达23.6%。     

A novel electroless plating of Ni-P-TiO2 nano-composite coatings

A new processing concept has been developed to produce nano-structured metal-matrix composite coatings. This method combines sol-gel and electroless plating techniques to prepare highly dispersive oxide nano-particle reinforced composite coatings. Transparent TiO₂ sol was added into the standard electroless plated Ni-P solution at a controlled rate to produce Ni-P-TiO₂ nano-composite coatings on Mg alloys. The coating was found to have a crystalline structure. The nano-sized TiO₂ particles (∼ 15 nm) were well dispersed into the Ni-P coating matrix during the co-deposition process. This technique can effectively avoid the agglomeration of nano-particles in the coating matrix. As a result, the microhardness of the composite coatings were significantly increased to ∼ 1025 HV₂₀₀ compared to ∼ 710 HV₂₀₀ of the conventional composite coatings produced with solid particle mixing methods. Correspondingly, the wear resistance of the new composite coatings was also greatly improved.     

添加CeO_2对MoS_2基复合涂层摩擦学性能的影响

针对MoS_2基复合涂层耐磨性差和承载能力低的问题,以不同含量(质量分数)的CeO_2作为添加剂,采用喷涂法在GCr15钢表面制备MoS_2基复合涂层。利用摩擦磨损试验机和划痕仪分别研究涂层摩擦磨损性能和结合强度,并借助金相显微镜对涂层磨损形貌进行表征。结果表明:添加适量CeO_2可以改善涂层的摩擦磨损性能,其最佳含量为2%,此时摩擦因数和磨损量均最小,分别为0.232和0.011 3 mm~3;同时结合强度从22 N提高到28.29 N。涂层磨损量随载荷的增大而增大;而载荷小于8 N时,涂层的摩擦因数随载荷的增大而减小,当载荷大于8 N时,摩擦因数又有回升趋势。添加稀土后涂层的承载能力有明显提高。未添加稀土时,涂层产生严重剥离,并发生磨粒磨损;添加2%CeO_2后,涂层发生轻微磨粒磨损,耐磨性得到显著提高。     

爆炸喷涂WC-12Co/MoS_2复合涂层的摩擦磨损性能

为进一步提高爆炸喷涂WC-12Co涂层的耐磨性,在WC-12Co合金粉末中添加不同比例的MoS2粉末,利用爆炸喷涂技术在Q235钢表面制备了系列WC-12Co/MoS2复合涂层.采用金相显微镜、扫描电子显微镜、X射线衍射仪、显微硬度计及摩擦磨损试验机对WC-12Co/MoS2复合涂层的微观组织形貌、结构、显微硬度、摩擦磨损性能进行了研究.结果表明,MoS2均匀的分布于复合涂层中,当MoS2含量为2%时,复合涂层的硬度、致密度变化不大,但摩擦系数和磨损率大幅度下降,分别为WC-12Co涂层的50%和36%.随着MoS2含量的增加,复合涂层的摩擦系数和磨损率均呈上升趋势.     

A study of electroless copper-phosphorus coatings with the addition of silicon carbide (SiC) and graphite (Cg) particles

Copper composite coating with graphite (C_g) and/or silicon carbide (SiC) particles were deposited by electroless plating. The surface morphology of the coatings that were analysed using scanning electron microscopy (SEM) showed that Cu particles were uniformly distributed. The obtained coating thickness was approximately ± 5 μm. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) techniques were used to characterise the structure and to study the phase transition of the coatings, respectively. Phases such as Cu, Cu₂O, Cu₃P, Cu₃Si, SiC and C_g were observed from X-ray diffraction patterns and the presence of Cu₂O, Cu₃P and Cu₃Si was confirmed by differential scanning calorimetry (DSC) studies. The results demonstrated that SiC and C_g particles have little influence on the phase transition of the coating. The hardness and wear resistance of Cu-P composite coatings were improved with the incorporation of SiC particles. The friction coefficient of Cu-P composite coatings decreased with the incorporation of C_g particles. Atomic force microscopy (AFM) results of coatings showed that the roughness of the coatings increased with the incorporation of SiC to the Cu-P coatings and decreased with the incorporation of C_g. Cu-P-C_g-SiC composite coatings showed a moderate roughness, hardness between Cu-P-SiC and Cu-P-C_g coatings, had low friction and good anti-wear properties. The anti corrosion resistance of the electroless Cu-P composite coatings on carbon steel were studied in 3.5% NaCl and 1 M HCl solutions by the potentiodynamic polarisation technique. The study revealed that the corrosion resistance increased with the incorporation of SiC particles in the Cu-P and Cu-P-C_g matrix but reduced with the incorporation of graphite.     

添加氧化镧的纳米Al2O3-13%TiO2等离子喷涂涂层高速摩擦磨损性能

以添加了少量氧化镧的团聚纳米Al2O3-13%TiO2粉末为原料,利用等离子喷涂技术制备了纳米陶瓷涂层。在MMS-1G型高速摩擦磨损试验机进行了摩擦磨损试验,利用扫描电镜和能谱仪对磨损表面进行了表征。结果表明:涂层组织呈现出典型的层状结构特征,界面结合良好。在高速摩擦磨损试验中,随着载荷的增加,涂层摩擦因数下降,而涂层微裂纹扩展引起涂层剥落,导致磨损率升高。     

Effect of applied current on the electrodeposited Ni-Al2O3 composite coatings

Nano-sized Al₂O₃ ceramic particles (50 nm) were co-deposited with nickel using electrodeposition technique to develop composite coatings. The coatings were produced in an aqueous nickel bath at different current densities and the research investigated the effect of applied current on microstructure and thickness of the coatings. The variation in some mechanical properties such as hardness, wear resistance, and the adhesive strength of the composite coatings is influenced by the applied current and this was also studied. The morphology of the coatings was characterized by scanning electron microscopy and energy dispersive X-ray spectroscopy. The hardness, wear resistance, and bond strength of the coatings were evaluated by Vickers micro-hardness test, pin-on-disc test, and tensile test, respectively. Results showed that the Al₂O₃ particles were uniformly distributed in the coatings, and the coatings deposited at a current density of 0.01 A/cm² was most favorable in achieving a maximum current efficiency which causes the co-deposition of a maximum amount of Al₂O₃ particles (4.3 wt.%) in the coatings. The increase in Al₂O₃ particles in the coatings increased the mechanical properties of the Ni-Al₂O₃ composite coatings by grain refining and dispersion strengthening mechanisms.     

纳米金刚石粒径对Ni-P化学复合镀层耐磨性和耐腐蚀性的影响

为提高化学镀镀层的耐磨性和耐腐蚀性,采用化学镀制备含不同粒径的纳米金刚石Ni-P-D复合镀层,通过SEM、XRD、摩擦磨损试验、磨粒磨损试验和电化学试验,探究纳米金刚石粒径对Ni-P镀层微观形貌、力学性能、摩擦磨损性能、磨粒磨损性能和耐腐蚀性能的影响。经化学复合镀可以得到与基体结合良好,厚度约为30 μm,含纳米金刚石的Ni-P-D复合镀层;含50 nm 金刚石的Ni-P-D复合镀层的硬度最高,抗摩擦磨损和磨粒磨损性能最好;随着纳米金刚石粒径减小,Ni-P-D复合镀层的摩擦系数和抗腐蚀能力提高,含5 nm金刚石的Ni-P-D复合镀层的摩擦系数最小,抗腐蚀能力最强。      

Al2O3-ZrO2 mixed oxide composite incorporated aluminium rich zinc coatings for high wear resistance

Corrosion resistance and wear resistance are the two important parameters for high performance of zinc galvanic coating. In the present work, the improvement of these two characteristics was achieved by the incorporation of Al₂O₃-ZrO₂ mixed oxide composite in the coating. Al₂O₃-ZrO₂ mixed oxide composite was synthesized from ZrOCl₂·8H₂O. Aluminium rich zinc coatings with high sliding wear resistance was developed from a galvanic bath containing the mixed oxide. Based on the performance of the coating during physicochemical and electrochemical characterization, the concentration of mixed oxide composite in the bath was optimized as 0.50 wt% Al₂O₃-0.50 wt% ZrO₂. While rich in Al-metal content in the coating caused high corrosion resistance, the incorporation of the mixed oxide improved structural characteristics of the coating resulting in high wear resistance also. The coating was nonporous in nature and even the interior layers had high stability. The coatings have potential scope for high industrial utility.     

Ni-P金刚石化学复合镀层制备及摩擦磨损性能分析

目的研究不同粒径微米金刚石对Ni-P金刚石化学复合镀层摩擦磨损性能的影响。方法选择出一组优良的Ni-P化学镀工艺参数,在镀液中分别加入不同粒径的金刚石微粒,制备含不同粒径微米级金刚石颗粒的化学复合镀层。用SEM和XRD,观察并分析了不同粒径金刚石对热处理前后Ni-P金刚石化学复合镀层微观形貌和组织结构的影响;通过硬度和摩擦磨损实验,研究了不同粒径金刚石颗粒对复合镀层硬度及摩擦磨损性能的影响。结果制备的复合镀层厚度为30μm左右,金刚石质量分数达到21%~25%,且金刚石均匀分散在Ni-P镀层中。热处理前镀层为非晶结构,经过400℃×2 h的热处理后,镀层晶化为硬度更高的Ni3P。金刚石能提高镀层硬度,其中粒径为9μm的复合镀层硬度最高,达到1261HV。Ni-P金刚石复合镀层的摩擦系数为0.4~0.52,随着金刚石粒径的增大,摩擦系数不断减小。金刚石使镀层的磨损机制发生了变化,随着金刚石粒径的增大,硬质合金球的磨损加剧。结论随着金刚石粒径的增大,镀层硬度增加,摩擦系数减小,耐磨性增大。