石墨/TiC改性镍基合金复合涂层的摩擦学性能

为降低纯镍基合金涂层在高接触应力下的摩擦因数并进一步提高其耐磨性能,运用等离子喷涂技术在45#钢表面制备石墨/TiC协同改性镍基合金复合涂层。结果表明：复合涂层的摩擦因数较纯镍基合金涂层降低47.45%,磨损质量降低59.1%。纯镍基合金涂层与GCr15钢对摩时,表面产生明显的滑移和粘着变形,从而使纯镍基合金涂层表现出多次塑变磨损和粘着磨损。在复合涂层的磨损表面形成较软的、富含石墨和铁氧化物的转移层,使得其摩擦因数显著降低,质量磨损大为减少。复合涂层的磨损机理主要为转移层的疲劳剥落。     

石墨/CaF2/TiC协同改善镍基合金喷涂层的摩擦磨损行为与机理（英文）

为了降低机械零件在强烈摩擦磨损条件下的摩擦因数,提高其耐磨性,制备了等离子喷涂石墨/CaF2/TiC/镍基合金复合涂层,研究其摩擦学行为及机理。结果表明,石墨/CaF2/TiC/镍基合金复合涂层的摩擦因数为0.22~0.288,较纯镍基合金涂层的降低了25.9%~53%,磨损率较之降低18.6%~70.1%。与GCr15钢球对摩时,复合涂层的磨损表面逐渐形成了由铁氧化物、石墨和CaF2组成的转移层,使GCr15钢球与复合涂层的摩擦转变为钢球与转移层的摩擦。由于转移层起到固体润滑作用,复合涂层的摩擦因数和磨损率大幅度降低。复合涂层的主要磨损机理是转移层在载荷的反复作用下而产生的层脱剥落。     

纳米Al2O3-40％TlO2复相陶瓷颗粒增强镍基合金复合涂层的摩擦学性能

运用等离子喷涂技术在7005铝合金表面制备Al2O3-40%TiO2纳米结构颗粒增强镍基合金复合涂层,分析其微观结构,研究其在不同载荷和速度条件下的摩擦磨损性能。结果表明：复合涂层主要由γ-Ni、α-Al2O3、γ-Al2O3和金红石型-TiO2等相组成,其摩擦因数和磨损失重较镍基合金涂层显著降低。在轻载3 N 时,复合涂层磨损表面的接触应力较低,主要发生微观切削磨损;当载荷上升至6~12 N时,接触应力高于磨损表面的弹性极限应力,复合涂层的磨损机理变为多次塑变磨损、微观脆性断裂磨损和磨粒磨损。随着速度的增大,磨损表面的接触温度逐渐升高,复合涂层以多次塑变磨损、疲劳磨损和粘着磨损为主。     

纳米Al2O3-40%TiO2复相陶瓷颗粒增强镍基合金复合涂层的摩擦学性能

运用等离子喷涂技术在7005铝合金表面制备Al2O3?40%TiO2纳米结构颗粒增强镍基合金复合涂层,分析其微观结构,研究其在不同载荷和速度条件下的摩擦磨损性能。结果表明：复合涂层主要由γ-Ni、α-Al2O3、γ-Al2O3和金红石型-TiO2等相组成,其摩擦因数和磨损失重较镍基合金涂层显著降低。在轻载3 N 时,复合涂层磨损表面的接触应力较低,主要发生微观切削磨损;当载荷上升至6~12 N时,接触应力高于磨损表面的弹性极限应力,复合涂层的磨损机理变为多次塑变磨损、微观脆性断裂磨损和磨粒磨损。随着速度的增大,磨损表面的接触温度逐渐升高,复合涂层以多次塑变磨损、疲劳磨损和粘着磨损为主。     

钴基合金Stelite3电火花强化层摩擦学性能研究

采用电火花强化技术在碳钢表面制备了钴基合金强化层,在不同摩擦速度和载荷条件下进行了摩擦磨损试验,研究了强化层的摩擦学行为与机制.结果表明:钴基合金强化层具有良好的耐磨性能;强化层的摩擦因数随摩擦速度和载荷的增加呈现出先增大后减小的变化规律.低速低载时,强化层主要磨损机理为微观切削与多次塑变磨损;高速高载时,磨损机理逐渐转变为粘着磨损、微观断裂、氧化磨损和一定的磨料磨损.     

TiC颗粒增强镍基合金复合涂层的摩擦学性能(英文)

运用等离子喷涂技术制备了TiC颗粒增强镍基合金复合涂层,分析了TiC颗粒增强镍基合金复合涂层的微观结构,研究了其摩擦磨损行为与机理。结果表明:TiC颗粒增强镍基合金复合涂层主要由γ-Ni,CrB,Cr7C3和TiC构成;复合涂层与基底材料间形成了厚度为9.4μm的过渡层,达到了冶金结合。当TiC颗粒含量为30%(体积分数)时,复合涂层的摩擦系数和磨损率均最低,即其摩擦系数为0.33,较纯镍基合金涂层降低了30%;其磨损率为0.3×10-3mm3/m,是纯镍基合金涂层的1/3。当载荷在6～10N的范围内时,复合涂层呈轻微磨损,其磨损机理主要为粘着磨损;当载荷达到12N时,复合涂层产生严重磨损,其磨损机制转变为硬质相的脱落和转移层的层脱剥落。     

WC-CeO_2/镍基合金复合涂层的微观结构与摩擦学性能（英文）

运用等离子喷涂技术在7005铝合金表面制备了WC和CeO2颗粒协同增强镍基合金复合涂层,研究了该复合涂层的微观结构和摩擦学性能。结果表明:加入CeO2颗粒细化了复合涂层的显微组织,使WC增强颗粒从圆形变为不规则多边形,并降低了其脱碳分解程度。不同PV值摩擦条件下,WC-CeO2/镍基合金复合涂层的摩擦系数和磨损失重均低于WC/镍基合金复合涂层和镍基合金涂层。PV值小于3.36 N·m/s时,复合涂层磨损表面的最大接触应力低于其弹性极限接触应力,主要发生微观切削磨损和疲劳磨损;PV值大于3.36N·m/s后,磨损表面的最大接触应力超过其弹性极限接触应力,接触温度也急剧上升至648℃,磨损表面出现明显的塑性变形和脱落,其磨损机制变为多次塑变磨损、磨粒磨损和粘着磨损,并伴有氧化磨损。     

TiC颗粒增强镍基合金复合涂层的摩擦学性能及磨损预测模型(英文)

运用等离子喷涂技术在铝合金表面制备TiCP/镍基合金复合涂层,研究干摩擦条件下载荷、速度和温度对复合涂层摩擦磨损行为与机理的影响规律;建立了基于最小二乘支持向量机(LS-SVM)的复合涂层磨损预测模型。结果表明:在不同摩擦条件下,TiCP/镍基合金复合涂层的摩擦因数和磨损质量均低于镍基合金涂层。LS-SVM模型对摩擦因数和磨损失重的预测时间仅为BP-ANN模型的12.93%,其预测精度分别比BP-ANN模型提高了58.74%和41.87%,可有效预测干摩擦条件下TiCP/镍基合金复合涂层的摩擦磨损行为。     

碳钢表面原位反应电火花沉积TiN金属陶瓷强化涂层摩擦磨损行为与机理

为了提高机械装备零部件的耐磨性能,运用电火花沉积技术,以工业纯钛作为电极材料,用高纯氮气作为反应与保护气体,在碳钢表面制备TiN金属陶瓷强化涂层。优化了电火花沉积工艺参数,分析了TiN金属陶瓷强化涂层的微观组织,测试了其力学性能,研究了其摩擦磨损行为与机理。结果表明:在最佳沉积工艺参数(放电电压80 V、沉积功率630 W、氮气流量15 L/min、比强化时间3 min/cm~2)时,可制备出最优性能的TiN金属陶瓷强化涂层,强化涂层与碳钢基体之间呈冶金结合,厚度约为50μm,并且该涂层具有优异的耐磨损性。在低载荷摩擦条件下(4 N),强化涂层表现为轻微磨损,其磨损机理主要是微观切削磨损;在中载荷摩擦条件下(8 N),强化涂层磨损量增大,其磨损机理转变为微观切削磨损和多次塑变磨损,并伴随三体磨粒磨损;在高载荷(12 N)摩擦条件下,强化涂层严重磨损,磨损机理主要为微观断裂磨损,并伴随着多次塑变磨损。     

Microstructure and Tribological Properties of WC-CeO2/Ni- base Alloy Composite Coatings

运用等离子喷涂技术在7005铝合金表面制备了WC和CeO2颗粒协同增强镍基合金复合涂层,研究了该复合涂层的微观结构和摩擦学性能。结果表明:加入CeO2颗粒细化了复合涂层的显微组织,使WC增强颗粒从圆形变为不规则多边形,并降低了其脱碳分解程度。不同PV值摩擦条件下,WC-CeO2/镍基合金复合涂层的摩擦系数和磨损失重均低于WC/镍基合金复合涂层和镍基合金涂层。PV值小于3.36 N·m/s时,复合涂层磨损表面的最大接触应力低于其弹性极限接触应力,主要发生微观切削磨损和疲劳磨损;PV值大于3.36N·m/s后,磨损表面的最大接触应力超过其弹性极限接触应力,接触温度也急剧上升至648℃,磨损表面出现明显的塑性变形和脱落,其磨损机制变为多次塑变磨损、磨粒磨损和粘着磨损,并伴有氧化磨损。     

TC4合金表面Cu/石墨复合镀层的摩擦磨损行为

采用无氰电镀工艺在TC4合金表面制备了Cu/石墨复合镀层,研究了镀层的组织结构和摩擦磨损行为。结果表明,采用无氰电镀方法能够在TC4合金表面制备出组织致密且与基体结合紧密的Cu/石墨复合镀层,但增加镀层中石墨的含量会降低镀层与基体合金的结合强度,并导致硬度小幅下降。摩擦磨损实验结果表明,Cu/石墨复合镀层具有优良的摩擦磨损防护性能,归因于石墨有效降低了镀层的摩擦系数和磨损率;对镀层磨损形貌、磨损产物和摩擦系数的综合分析结果表明,纯铜镀层的摩擦磨损机制主要为犁削磨损、黏着磨损和剥层磨损,Cu/石墨复合镀层的磨损机制为轻微的削层磨损和疲劳磨损。     

Tribological Behavior of In Situ TiC/Graphene/Graphite/Ti6Al4V Matrix Composite Through Laser Cladding

The TiC/graphene/graphite/Ti6Al4V composite coating was prepared by laser cladding.The microstructure and tribological behavior of the coating were studied.The in situ reaction between graphene and Ti occurred,and feathery TiC was formed.The feathery TiC was homogeneously distributed between α'acicular martensites which was refined with the addition of graphene.Some graphene was transformed into a11otrope graphite under the laser irradiation.The TiC hard particles and the self-lubrication of graphene/graphite improved the wear resistance of composite coating.The wear rate and friction coefficient of TiC/graphene/graphite/Ti6A14V composite coating decreased with the increase in sliding speed,a mechanical mixing layer (MML) was formed on the wear surface of the composite coating under the frictional heat,which protected the substrate and reduced the contact.Because of the self-lubricating properties of graphene/graphite,interlayer sliding occurred easily,which also effectively reduced friction.The wear rate of TiC/graphene/graphite/Ti6A14V composite coating increased with the increase in load,but the friction coefficient decreased.The plastic deformation of subsurface layer was more serious under high load,and a stable self-lubricating MML with a protective effect was formed between the wear interfaces,which reduced the friction coefficient.With the increase in load,the wear mechanism changed from abrasive and oxidation wear to delamination,fatigue and oxidation wear.     

Wear behaviour of an FeAl intermetallic alloy containing carbon and titanium

FeAl based alloys with carbon and titanium additions were prepared using arc induction melting and their effect on wear behaviour was investigated using ball-on-disk technique. The experimental results showed that carbon addition to FeAl alloys results in formation of perovskite-type Fe₃AlC_0.5 carbide phase and graphite. Addition of Ti promotes the formation of TiC and Fe₃AlC_0.5 and prevents the formation of graphite in the alloy. Hardness and wear resistance of FeAl based alloys increase with increase in the volume fraction of carbides. The FeAl alloys containing Ti exhibited low wear rate and coefficient of friction. Examination of wear tracks revealed micro ploughing at a lower load of 5N. Thin surface flakes with traces of their detachment were observed at a higher load of 10N. It was also observed that presence of graphite in localized regions reduce the wear resistance of the alloy. The results are correlated with observed microstructure and hardness.     

Dry sliding friction and wear behaviors of TiCp／ZA—12 composites

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