纳米SiO2对火焰喷涂尼龙1010涂层干摩擦磨损性能的影响

为了探讨纳米SiO2(n-SiO2)对火焰喷涂尼龙(PA)1010涂层干摩擦磨损性能的影响,采用MRH-3型环-块摩擦磨损试验机对不同n-SiO2含量的尼龙1010涂层的干摩擦磨损性能进行了测试;并利用扫描电子显微镜(SEM)对复合涂层的磨损表面进行观察,以探讨n-S iO2对火焰喷涂尼龙1010涂层摩擦磨损性能的影响机制。结果表明:n-SiO2的加入能明显提高尼龙涂层的耐磨性,降低摩擦因数,疲劳磨损、粘附磨损及犁切现象明显减轻;当n-SiO2含量为1.5%(质量分数)时,复合涂层摩擦磨损性能最佳,试验条件下磨损量降低近4倍,摩擦因数降低23%,跑合期降低44%,复合涂层与GCr15钢环对磨时的磨损机制主要为疲劳磨损和轻微的粘附磨损。     

球形铸造碳化钨对PDC钻头喷焊层冲蚀性能的影响

本研究采用氧乙炔喷焊方法制备了不同含量的球形碳化钨和多角状碳化钨颗粒增强的镍基喷焊涂层,研究了钢体PDC钻头碳化钨喷焊层的抗冲蚀性能。结果表明：随着球形碳化钨含量的降低,喷焊层的显微硬度降低,断裂韧性增加,孔隙率先增大后趋于稳定;喷焊涂层的抗冲蚀性随球形碳化钨含量的降低呈先降低后升高的趋势,耐腐蚀性是影响喷焊涂层抗冲蚀性最主要的因素。当球形碳化钨含量为30%时,样品抗泥浆腐蚀性能最差,腐蚀—冲蚀互作用最强,导致样品受冲蚀磨损最严重。建议球形碳化钨含量不低于40%,可以保持喷焊层较高的硬度和抗冲蚀性能。     

碳钢奥氏体不锈钢材料在水电工程中应用的局限性

通过对水电站典型应用材料(55钢、1Cr18Ni9Ti、0Cr13Ni5Mo)在冲蚀磨损过程中电化学腐蚀及抗冲蚀磨损性能研究,区分出纯磨损、纯腐蚀、磨损对腐蚀的促进分量及腐蚀对磨损的促进分量等在材料失效过程中各占的比例,考察了试验材料的抗冲蚀磨损特性及其磨损与腐蚀间的交互作用,分析了其失效机制。结果表明:不同的冲蚀速度下,0Cr13Ni5Mo不锈钢的冲蚀磨损失重率最小,55钢最大;纯磨损是材料失去的主要方式:55钢虽然纯磨损量较小,但腐蚀及其磨损与腐蚀的交互作用失去量大,1Cr18Ni9Ti不锈钢虽然纯腐蚀量小,但纯磨损量大,因而都有应用的局限性。     

激光熔覆Ni基WC合金的固体粒子冲蚀磨损研究

采用激光熔覆技术,在45#钢表面制备Ni基WC合金涂层,利用扫描电镜分析了熔敷层的微观组织,利用显微硬度计、固体粒子冲蚀磨损实验机对涂层的性能进行了测试研究.结果表明:随Co-WC质量分数的增加,试样的硬度逐渐增大,其冲蚀抗力增大,当质量分数超过一定数值后冲蚀抗力减小.质量分数为40%的Co-WC复合涂层有良好的冲蚀抵抗力.     

硬质合金基体上TiN与TiAlN涂层冲蚀磨损特性研究

采用离子束辅助真空脉冲过滤弧离子镀技术,在硬质合金YG6基体上沉积两种氮化物涂层TiN、TiAlN,检测了涂层的微观结构及其主要物理机械性能。对两种涂层进行气体冲蚀磨损试验,利用扫描电子显微镜(SEM)对冲蚀表面进行观察,获得涂层冲蚀形貌特征。通过检测涂层的冲蚀磨损量和磨损率,分析涂层的冲蚀磨损性能,表明TiAlN涂层比TiN表现出了更强的抵抗冲蚀磨损的能力。通过分析两种涂层的冲蚀表面形貌特征,发现两种涂层材料的冲蚀去除机制有所不同。TiN涂层表现出典型的脆性断裂去除特点,而TiAlN涂层主要呈现微切削和疲劳断裂的特征。     

动车组表面聚氨酯涂层冲蚀性能分析

采用气流喷砂式冲蚀实验机,对动车组聚氨酯涂层进行冲蚀性能研究。利用扫描电子显微镜及表面轮廓测量仪,检测了聚氨酯涂层的表面冲蚀形貌及冲蚀磨损,比较分析了粒子速度、入射角度对聚氨酯涂层冲蚀磨损率及冲蚀形貌的影响规律。研究发现:聚氨酯涂层冲蚀磨损机制为低角度冲蚀时微切削机制起主导作用,高角度冲蚀时脆性破碎机制起主导作用;冲蚀参数对涂层的冲蚀磨损率影响规律为:随粒子速度呈现指数增长(指数为2.27),随入射角度先增后减规律(峰值在30°入射时)。     

一种模拟舰船表面破坏的冲蚀、空蚀和腐蚀交互磨损试验研究

海洋装备表面材料破坏的主要原因是冲蚀、空蚀和腐蚀及其交互作用,而量化其表面磨损程度对海洋装备材料和结构的设计具有重要意义。冲蚀、空蚀和腐蚀交互磨损试验台是研究海洋装备表面材料破坏的有效工具。通过流场数值对比分析,在研究冲蚀和空蚀交互作用的基础上,优化设计了冲蚀、空蚀和电化学腐蚀交互磨损综合试验台,完成了人造海水中,不同材料的舰船工作表面受到高速流体冲击产生的冲蚀、空蚀和电化学腐蚀交互磨损试验。结果表明:同一种金属材料冲蚀、空蚀和电化学腐蚀交互作用的失重量大于冲蚀、空蚀和自然腐蚀交互作用的失重量,高强度塑性金属材料的腐蚀磨损较为严重,其三者交互作用的磨损程度大于低强度塑性金属材料。     

模具钢表面Co/TiC熔覆层的组织与高温磨损性能

利用6 kW横流CO2激光器制备了Co50熔覆层和不同成分配比的Co/TiC复合涂层来改善H13模具钢表面的热磨损性能.借助X射线衍射(XRD)、扫描电子显微镜(SEM)、显微硬度计和高温摩擦磨损试验机分析了涂层的结合特征、物相组成和不同温度下的摩擦磨损性能.结果表明,当预置层粉末TiC含量(重量百分比)小于等于20％时,熔覆层与H13钢基材呈良好的冶金结合;随着TiC含量的增加,Co/TiC复合涂层截面平均显微硬度呈上升趋势,但涂层中基体相种类减少:Co+10％TiC涂层由TiCo3、Cr2Ni3和Cr-Ni-Fe-C组成,Co+20％TiC涂层由Cr2Ni3和γ-Co组成,Co+30％TiC涂层为γ-Co固溶体.Co+ 20％ TiC涂层的高温耐磨性比C050涂层显著提高,摩擦系数平稳;700℃时复合涂层的磨损机制主要为氧化磨损和疲劳磨损.结果显示Co+20％TiC涂层具有良好的综合性能.     

风机叶片用涂层的抗冲蚀性能的研究

针对风机叶片用涂层的抗冲蚀性能进行了研究,从磨损原理入手,分析研究了等离子喷涂涂层和表面粘涂涂层的抗冲蚀性能。采用NIWC35涂层和陶瓷耐磨修补剂（11680）涂层,对涂层结合强度、硬度、显微结构及抗冲蚀性能进行了研究。试验结果表明,等离子喷涂涂层在低角度下的冲蚀明显低于高角度下的冲蚀;而耐磨修补剂（11680）涂层从冲蚀情况看,Al1O3与树脂的粘结状况是良好的,在冲蚀率上,高角度下耐剖蚀性能比低角度下好。     

冲击形式产生的冲蚀、空蚀和腐蚀联合磨损试验研究

舰船等海洋运输装备在海水中行驶时,船体表面受到含沙海水的冲蚀磨损,舰船行驶速度变化引起的空蚀磨损,以及海水的腐蚀磨损,因此舰船表面材料的破坏形式是冲击式的冲蚀、空蚀和腐蚀联合磨损。为了研究联合磨损的影响因素,研制冲蚀、空蚀和腐蚀联合磨损试验台,并实验研究沙粒浓度、沙粒尺寸、含盐浓度以及冲蚀速度对45钢试件的联合磨损影响规律。实验结果表明:冲蚀、空蚀和腐蚀联合磨损程度强于冲蚀和空蚀交互磨损或单纯腐蚀磨损,在较低的沙粒浓度和较低的含盐浓度条件下,金属材料联合磨损质量损失与沙粒浓度、沙粒尺寸、含盐浓度和冲蚀速度均成正比关系。磨损面形貌分析表明:随着沙粒浓度、沙粒尺寸、含盐浓度、冲蚀速度的增加,试件表面的冲蚀沟和空蚀孔的磨痕深度和面积增大,而在人造海水中,试件表面不仅存在冲蚀沟和空蚀孔,还产生了腐蚀坑。     

不同激光熔覆材料涂层的耐磨性能比较

本文研究了宽带激光熔覆不同熔覆材料的复合涂层的耐磨性能。结果表明:Ni60B熔覆层的硬度高于40Cr基材的硬度,Ni60B+WC梯度复合涂层具有最高的硬度,对于提高零件的抗磨损性能比较有利;Ni60B熔覆层和Ni60B+WC熔覆层均适合修复轴类零件;三层梯度复合涂层磨痕宽度最小,具有最好的耐磨性。     

镍基纳米复合电刷镀层的滑动磨损性能研究

用电刷镀技术制得了镍基 n-SiO_2复合镀层、镍基 n-SiC 复合镀层以及镍基镀层,并对镀层的滑动磨损性能进行了试验研究.纳米复合镀层的表面形貌比较细腻,镀层中纳米粒子分布均匀,与基质金属结合紧密.显微硬度高,可达到 HV692,比镍基镀层提高约50%.滑动磨损试验结果表明,纳米粒子的加入可以提高镀层的耐磨性.纳米复合镀层的磨损机制以疲劳磨损为主,而纯镍镀层以粘着磨损为主.     

Investigating Corrosion Performance and Corrosive Wear Behavior of Sol–gel/MAO-Coated Mg Alloy

In this study, a hydroxyapatite composite coating was prepared by a sol–gel technique on the micro-arc oxidation (MAO)-coated AZ31 Mg alloy to seal the micro-pores. The composite coating achieved a larger hardness value and two times thickness more than pure MAO coating. The corrosion and wear resistance of the sol–gel/MAO coating in simulated body fluid were investigated compared to MAO coating. It was found that the composite coating presented a positive corrosion potential and a lower corrosion current density than MAO coating. The sol–gel/MAO composite coating could provide more effective barrier against corrosive ions than single MAO coating for AZ31 alloy. In the wear tests, a ball-on-disk tribometer was used to study the effect of loads on the wear properties of the coatings at 37 °C. The wear resistance of sol–gel/MAO composite coatings was apparently superior to MAO coating. The wear mechanisms of abrasion and adhesion in composite coatings are investigated. Finally, two physical models for the corrosion and sliding wear mechanisms of sol–gel/MAO composite coatings are proposed, respectively.     

Microstructure and wear properties of in situ TiC/FeCrBSi composite coating prepared by gas tungsten arc welding

Using a gas tungsten arc welding (GTAW) process, in situ synthesis TiC particles reinforced Fe-based alloy composite coating has been produced by preplaced FeCrBSi alloy, graphite and ferrotitanium powders. The microstructure and wear properties of the composite coatings were studied by means of scanning electron microscopy (SEM), X-ray diffractometer (XRD) and wear test. The effects of thickness of the pre-placed powder layer on the microstructure, hardness and wear resistance of the composite coatings were also investigated. The results indicated that TiC particles were produced by direct metallurgical reaction between ferrotitanium and graphite during the GTAW process. TiC particles with sizes in the range of 3–5 μm were dispersed in the matrix. The volume fraction of TiC particles and microhardness gradually increased from the bottom to the top of the composite coatings. The TiC-reinforced composite coatings enhance the hardness and wear resistance. The highest wear resistance of the composite coating with a 1.2 mm layer was obtained.     

Microstructure and wear properties of in situ TiC/FeCrBSi composite coating prepared by gas tungsten arc welding

Using a gas tungsten arc welding (GTAW) process, in situ synthesis TiC particles reinforced Fe-based alloy composite coating has been produced by pre-coated FeCrBSi alloy, graphite and ferrotitanium powders on the substrate. The microstructure and wear properties of the composite coatings were studied by means of scanning electron microscopy (SEM), X-ray diffractometer (XRD) and wear test. The effects of thickness of the pre-coated powder layer on the microstructure, hardness and wear resistance of the composite coatings were also investigated. The results indicated that TiC particles were produced by direct metallurgical reaction between ferrotitanium and graphite during the GTAW process. TiC particles with sizes in the range of 3–5 μm were dispersed in the matrix. The volume fraction of TiC particles and microhardness gradually increased from the bottom to the top of the composite coatings. The TiC-reinforced composite coatings enhance the hardness and wear resistance. The highest wear resistance of the composite coating with a 1.2 mm layer was obtained.     

纳米和微米La2O3颗粒增强镍基复合镀层的摩擦磨损性能

用复合电沉积工艺制备了纳米和微米La2O3颗粒增强镍基复合镀层，在销盘式滑动磨损试验机上考察了复合镀层在干摩擦条件下的摩擦磨损性能，用扫描电子显微镜分析了其磨损机理。结果表明：在干摩擦条件下，纳米La2O3颗粒增强复合镀层的摩擦磨损性能明显优于微米La2O3颗粒增强复合镀层；纳米La2O3增强镍基复合镀层的磨损主要表现为轻微磨粒磨损特征，而微米La2O3增强镍基复合镀层的磨损机制为剥层磨损和磨粒磨损。     

碳纳米管镍基复合刷镀层的组织和性能

研究了碳纳米管镍基复合刷镀层的组织、显微硬度和耐磨性等。结果表明：与常规镀层相比，含有碳纳米管的复合镀层组织明显细化，显微硬度有较大的提高，硬度热稳定性和耐磨性得到了明显的提高。     

火焰喷涂PA1010/n-SiO2复合涂层干摩擦磨损性能

利用火焰喷涂法制备PA1010/n-SiO2复合涂层,并采用均匀试验设计方法研究涂层在干摩擦条件下同GCr15 钢环配副时的摩擦学性能;利用SPSS 12.0统计软件对试验结果进行回归分析, 建立涂层摩擦系数和磨损质量损失同pv值 (摩擦载荷与摩擦速度的乘积)相关性的数学模型;利用示差扫描量热仪(Differential scanning calorimetry, DSC)和扫描电子显微镜(Scanning electron microscope, SEM)对复合涂层的热性能和磨损表面形貌进行分析。结果表明,n-SiO2的加入能明显提高涂层的结晶性能、耐磨性能。当n-SiO2含量为1.5%时,复合涂层摩擦磨损性能最佳,在试验条件下磨损质量损失降低近4倍,摩擦因数降低23％,跑合期缩短44％,复合涂层与GCr15钢环对磨时的磨损机理主要为疲劳磨损和轻微的粘附 磨损。     

Ni-Si3N4复合电镀工艺与耐磨性研究

研究了镀液Si3N4浓度，阴极电流密度、pH值、温度和搅拌方式等工艺参数对Ni—Si3N4复合镀层微粒含量和镀层硬度的影响，在盘销摩擦磨损实验机上对镀层进行了磨损实验。通过实验确定了Ni-Si3N4复合电镀的最佳工艺。结果表明：随着Si3N4共析量的增多复合镀层硬度提高，耐磨性增强；在浸油润滑的条件下，复合镀层的摩擦因数低于纯镍镀层，复合镀层的磨损量小于普通镀镍层。磨痕表面观察表明复合镀层的磨损以磨料磨损为主。