化学沉积法制备Ni-P-SiC复合镀层的研究

研究了在碳钢基材表面进行化学沉积Ni-P-SiC复合镀层的工艺和条件,对镀层的成分进行了扫描分析,对镀层的金相组织进行了观察分析;结果表明SiC硬质纳米粒子嵌入,使Ni-P合金基质产生沉淀强化,使镀层硬度增加.通过对磨实验和腐蚀实验证明,复合镀层可使碳钢零件耐磨性能提高3倍,可使碳钢零件耐蚀性能提高4倍,有效地延长了钢铁零件的使用寿命.     

聚四氟乙烯、石墨等粒子与镍磷化学共沉积复合镀层的研究

由化学镀得到的聚四氟乙稀、石墨、氟化石墨、硫化钼及氟化钙粒子等与镍磷一起沉积的五类自润滑复合镀层。在环块试验机及销盘试验机上研究了其摩擦磨损特性。得出其摩擦系数与抗磨性、试验负荷、粒子含量和镀层的热处理与否有关。与淬火GCr15和氮化过的钢相比,自润滑复合镀层具有低的摩擦系数,比之纯Hi-p镀层其摩擦系数也较低。 由AES和SEM对磨损表面进行分析,当表面的Ni-p逐步磨去时,固相润滑粒子逐步暴露。对细粒子来说(如小于2μm的PTFE)能在对磨件表面形成转移膜,降低摩擦系数,其磨损率略有提高。但如粒子过大(如大于2μm的石墨)则石墨粒子压延并抛光,或碎裂脱落,也能转移并降低摩擦,但使磨损量大为增加。     

镍、磷和空心微珠复合镀层摩擦磨损性能研究

运用化学镀方法,把空心微珠作为第二相加入化学镀镍和磷镀液中,制得以镍、磷和空心微珠为主的复合镀层.X射线分析显示,复合镀层经过热处理后由非晶态变成晶态.复合镀层经过热处理后显微硬度及摩擦学性能提高.复合镀层耐磨性比纯镍和磷镀层提高约30%,抗腐蚀性提高77%.运用SEM和XPS等对复合镀层性能和结构进行分析.     

Tribological behaviors of spot-textured TiN coatings on M2 high-speed steel under boundary lubricated conditions

The effect of sliding duration on the tribological behaviors of spot patterned coatings was investigated. Two patterns based on physical vapor deposition （PVD） TiN coatings were used, such as, in-lined （IN） and staggered （ST） spots. The tribological behaviors were evaluated by using a Cameron-Plint wear test rig. The M2 steel discs deposited TiN coatings with IN and ST patterns slid against the ASSAB 17 tool steel pins at a speed of 0.23 m/s, in Shell Tellus T32 lubricant and were loaded with 900 N. The testing results on disc specimens with two types of PVD TiN spot patterns, all coated with a bias voltage of-180 V and slid for 4, 8 and 11 h respectively, were presented. The results revealed that the in-lined coatings possessed relatively better wear behaviors than the staggered pattern coatings. Mechanisms for such superiority and for the cause of peeling were discussed. A relevant design approach was suggested for the application of such patterned coatings.     

镍基纳米碳管复合镀层的摩擦磨损性能

利用化学镀方法制备镍基纳米碳管复合镀层,用扫描电镜分析了镀层的表面形貌,并用销-盘式磨损试验机研究了复合镀层在干摩擦条件下的摩擦磨损行为.结果表明:纳米碳管均匀地嵌入在镍基体中,镍基纳米碳管复合镀层具有优良的耐磨性能;由于纳米碳管的自润滑作用,复合镀层的摩擦系数随着纳米碳管体积分数的增加而逐渐降低.     

仿生凹坑与纳米碳化硅/镍基复合镀层耦合表面的磨损性能

为了探讨凹坑形态与纳米碳化硅/镍基复合镀层耦合表面的磨损性能,采用激光技术和电沉积技术制备了由凹坑形态和纳米碳化硅/镍基复合镀层构成的仿生耦合表面,并进行了摩擦和磨损试验。结果表明,仿生耦合表面的磨损性能高于单纯复合镀层的磨损性能;随着磨损载荷的增加和磨损时间的延长,试样表面磨损机制由以塑性磨损为主逐渐转变成以粘着磨损、磨粒磨损为主的磨损机制。     

微米氧化铝/尼龙复合材料煤泥润滑条件下滚滑摩擦磨损行为

使用微米氧化铝(Al2O3)为增强剂,以尼龙1010为基体,进行氧化铝/尼龙复合材料在煤泥润滑条件下的滚滑动摩擦磨损实验.通过实验发现,水能降低氧化铝/尼龙复合材料的摩擦系数,但增大了磨损量.煤泥润滑时尼龙1010材料的摩擦系数为0.096;氧化铝/尼龙复合材料的平均摩擦系数为0.089,只有纯尼龙的92.7%.尼龙磨损量是3.32mm3;Al2O3/尼龙复合材料的磨损量平均为15.73mm3;Al2O3/尼龙复合材料的平均磨损量平均是尼龙的4.74倍.     

Processing technique and sliding friction and wear behavior of TiB2／ZA27 composite

In-situ TiB2 particles reinforced ZA27 composite was prepared by the stir-casting technique and a twostep method. TiB2/Al composite was produced by incorporating K2 TiF6, KBF4 salts and other agents into Al melt. As a master alloy, TiB2/Al composite was used to manufacture TiB2/ZA27 composite, which results in the generation of well-distributed reinforcing TiB2 phase. The hardness, friction and wear behavior of TiB2/ZA27 composite were investigated. The results show that the hardness of the composite is enhanced with increasing the content of TiB2 particles, the incorporation of TiB2 reduces the wear rate of TiB2/ZA27 composite and improves the friction property under lubricated and dry sliding friction conditions. The worn track width of ZA27 alloy is 1.6 and 2.5 times as long as that of 2.1%TiB2/ZA27 composite at 150 N and 700 N load under lubricated conditions, which indicates that TiB2/ZA27 composite possesses higher bearing ability.     

等离子喷涂NiCr/Cr_2C_3、Ni/C及其复合涂层的耐磨性能

为了加强车辆机械零件的表面防护,采用等离子喷涂工艺在304N不锈钢表面分别制备了NiCr/Cr_2C_3涂层、Ni/C涂层以及NiCr/Cr_2C_3和Ni/C复合涂层,观察了涂层组织形貌,测试了涂层硬度和耐磨性,分析了涂层的摩擦磨损机理.结果表明,3种涂层中NiCr/Cr_2C_3和Ni/C复合涂层的耐磨性能最好.金属粘结相NiCr可以起到足够的支撑作用,从而防止涂层剥离与黏着磨损的产生.Ni/C作为固体润滑剂,通过自润滑作用降低了涂层的整体摩擦系数.     

铝合金上电沉积Ni-P-CNTs复合镀层及其摩擦性能研究

采用复合电沉积法在铝合金表面上制备了镍 磷 碳纳米管（Ni-P-CNTs）复合镀层,并用X射线衍射（XRD）和扫描电镜（SEM）对其进行了表征,分析了电流密度和镀液中碳纳米管的质量浓度对复合镀层形貌及其摩擦磨损性能的影响.当电流密度为3.0 A/dm2时可以得到表面光亮、平整的复合镀层,复合镀层中碳纳米管体积分数随着镀液中碳纳米管质量浓度的增加而增加.Ni-P-CNTs复合镀层比Ni-P镀层具有更高的硬度、耐磨性能和更低的摩擦系数.随着复合镀层中碳纳米管体积分数的增加,复合镀层的磨损量和摩擦系数逐渐降低.复合镀层摩擦性能的改善是由于碳纳米管具有优异的力学性能和良好的自润滑性能.     

Friction properties of OTS SAMs and silicon surface under water lubrication

The friction and wear properties of silicon surface covered with octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) were investigated by a UMT-2 microtribometer with and without water as lubricant, and then compared with that of bare silicon surface. Dry friction measurement results show that OTS SAMs have a very low friction coefficient compared to bare silicon surface under lower sliding velocity and normal contact load. However, heavy wear occurs on OTS SAMs under higher contact stress and sliding velocity. Under water lubrication, OTS SAMs can prevent wear obviously and meanwhile present low coefficient of friction even under high velocities. The improved frictional and anti-wear property on OTS SAMs surface is attributed to the hydrophobic property of OTS and hydrodynamic effect of water. Furthermore, a wear critical phase diagram for OTS SAMs with and without water was proposed, which indicates that OTS SAMs working under water lubrication owns a wider range of available load and velocity to reduce friction and prevent wear. Funded by the National Natural Science Foundation of China (Nos. 50575123, 50275071, 50545035) and National Basic Research Program of China (“973” Program) (No. 2003CB716205)     

电弧离子镀TiN/TiAlN复合涂层摩擦磨损性能研究

利用阴极电弧离子镀技术,在硬质合金基体上制得5层和20层TiN/TiAlN复合涂层.研究表明,这两种涂层均为典型的B1-NaCl面心立方结构,且均呈(200)择优取向.两种涂层表面光滑平整,粗糙度分别为0.32和0.11,硬度为1 470HV和2 000HV .20层复合涂层的摩擦系数和比磨损率低于5层,表明增加复合层数有利于提高涂层的耐磨损性能,涂层的磨损机理为磨粒磨损.     

Microstructure and tribological properties of laser clad Ni-Ag/Tic composite coating

Ni-Ag/TiC composite coating was prepared on the 45 steel substrates by means of laser cladding. Microstructure and wear properties of composite coatings were analyzed using optical microscopy, field emission scanning electron microscopy and wear machine. The experimental results show that defects, such as cracks and pores, do not occur in the laser-cladded Ni-Ag/TiC composite coating and 45 steel substrate, and they present good metallurgical bonding between them. Compared with Ni/TiC composite coating, micro- hardness values of the two coatings do not present evident differences. The wear experiment result shows that Ni-Ag/TiC composite coated with Ag possesses low friction coefficient and good wear resistance compared with Ni/TiC composite coating.     

脉冲电沉积Ni-SiC复合镀层的组织形貌与性能研究

利用直流(DC)和脉冲(PRC)两种电沉积方法制备了Ni-SiC复合镀层.利用X射线衍射仪(XRD)检测了镀层的微观结构与性能,通过扫描电镜(SEM)观察了镀层的表面形貌.结果表明:脉冲方法得到的纯镍镀层和复合镀层结晶晶粒更细小均匀,表面更致密平整.当镀层中SiC含量约为10.6%时脉冲镀层的宏观残余应力较直流镀层降低19.5%,硬度提高6.6%.     

Morphology and tribological properties of Ni/n-SiO_2 composite coatings by pulse-reverse current brush-plating

1INTRODUCTION Pulse reversecurrent(RC)platingisanew technologycomingwithpulsecurrent(PC)andre versecurrent.Onthisaspect,earlierstudiesmani festedthat[16],intheconditionofRC,theeffectofelectricdoublelayerwasrestrained,thecontrol ofcrystallinegrowthwasenfor…     

聚苯胺／氟碳乳液复合涂层的防腐蚀性能

以聚苯乙烯磺酸（PSSA）为掺杂剂,制备水性聚苯胺（PANI）-蒙脱土（MMT）复合材料,再以水性氟碳乳液（FC）为成膜物,制备水分散体PANIL氟碳乳液复合涂层材料用于A3钢的防腐蚀。利用平衡开路电位（OCP）、电化学交流阻抗谱（EIS）、Tafel曲线考察了掺杂剂和蒙脱土对防腐蚀性能的影响。XRD结果表明PANI—MMT复合材料中的蒙脱土以片层剥离状态存在;当n（PSSA）：n（An）=1．5：1和m（An）：m（MMT）=1：2．5时,复合涂层具有较高的阻抗,显著提高了金属的腐蚀电位（-0．75V）,降低了金属的腐蚀电流密度（10^-7.5A／cm^2）。     

激光熔覆Fe基非晶／纳米晶复合涂层的组织与性能

对以激光熔覆方式在45钢基体上制备的FeNiSiBVRE非晶涂层进行激光晶化,制备非晶／纳米晶复合涂层.利用X射线衍射仪、透射电镜、扫描电镜和磨损试验机研究非晶／纳米晶复合涂层的组织与性能.研究结果表明,涂层存在着分层结构,组成相有晶化相、非晶相和纳米晶相;涂层底部和顶部的显微组织由大量的稀土树枝晶、板条状硼化物和粒状碳化物组成,涂层中部的显微组织是由大量的纳米晶相镶嵌在非晶基体上构成.与没有进行激光晶化的非晶涂层相比,涂层的耐磨损性能下降.其磨损机制以粘着磨损和剥层磨损为主.     

Effects of h-BN content on properties of Ni-Cr/h-BN composite

Ni-Cr/h-BN self-lubricating composities were prepared by powder metallurgy (P/M) method. The effects of hexagonal boron nitride (h-BN) content on the mechanical and tribological properties of the Ni-Cr/h-BN composites were investigated. The corresponding frictional models were established to analyze the formation of the lubricant h-BN films on the surfaces of the Ni-Cr/h-BN composites. The results show that, when the content of h-BN increases from 5% to 15% (mass fraction), the bending strength of the Ni-Cr/h-BN composite decreases from 96.670 MPa to 17.319 MPa, and the hardness (HB) decreases from 33 to 14. The friction coefficient of the Ni-Cr/h-BN composite decreases firstly from 0.385 to 0.216, and then increases to 0.284, while the wear rate decreases firstly from 4.14×10⁻⁹ kg/(N·m) to 1.35×10⁻⁹ kg/(N·m), then increases to 2.36×10⁻⁹ kg/(N·m). The best comprehensive mechanical and tribological properties can be obtained between 10% and 12% h-BN addition.     

Morphology and tribological properties of Ni/n-SiO2 composite coatings by pulse-reverse current brush-plating

Ni/n-SiO₂ composite coating was electrodeposited by brush-plating with pulse-reverse current(RC). The morphology, hardness, and tribological properties of the coating were investigated and compared with those of Ni and composite coatings electrodeposited with direct current (DC). The results indicate that Ni/n-SiO₂ composite coating electrodeposited by RC, because of RC and the nano powders, has denser coating, finer crystal grains, higher hardness (HV650.0, nearly 1.5 times higher than that of Ni coating electrodeposited by DC) and lower friction coefficient (nearly 0.62), as a result, in the wearing experiment, the Ni/n-SiO₂ composite coating electrodeposited by RC has the least worn loss. So this kind of coating has better wear resistance. And RC electro brush-plating can be used as a new technology of brush-plating in the area of wear resistance. Foundation item: Project (50235030) supported by the National Natural Science Foundation of China; Project (51489020104JS9102) supported by the National Key Laboratory for Remanufacturing     

风沙环境下钢结构涂层的冲蚀摩擦学性能

针对内蒙古中西部地区钢结构体系表面涂层长期遭受风沙环境冲蚀的这一现状,采用气流挟沙喷射法,模拟风沙对钢结构涂层的冲蚀.研究了风沙冲蚀力学参数对钢结构涂层冲蚀率的影响;探讨了涂层冲蚀损伤的摩擦学机理;分析了钢结构涂层的冲击摩擦因数变化规律.结果表明:涂层的冲蚀率均随着冲蚀速度呈指数增长,速度指数n为2.39~2.43;在45°时涂层的冲蚀率最大,90°时涂层的冲蚀率最小,低冲角时的冲蚀率大于高冲角时;涂层的摩擦因数处于0.37~0.42,涂层磨损的Taber指数为81.9×10-3mg/r,涂层的耐磨性较差.涂层损伤的摩擦学机理是:低冲角时的微切削作用或高冲角时的挤压凿削作用造成涂层的损伤占主导,涂层表面微裂纹扩展交叉,以致断裂剥落,造成的损伤次之;涂层冲击摩擦因数离散性较大,且随角度增长呈降低趋势;冲击摩擦因数与冲蚀率随角度的变化并不一致.