纳米Al2O3弥散强化复合涂层的制备及耐磨性研究

将纳米Al2O3与Ni基自熔性合金F102的复合粉末用氧乙炔焰热喷焊工艺制各复合涂层，研究了纳米Al2O3的加入呈对组织和耐磨性的影响。结果表明，当纳米A12O3质量分数为0．25％时，涂层的耐磨性最好，与25％WC复合涂层的耐磨性相当。     

等离子喷涂陶瓷涂层的动态防滑性能和耐磨性

采用等离子喷涂技术制备Al2O3-13%Ti O2和WC复合涂层。利用MMS-1G高速摩擦试验机评价涂层在高速动态条件下防滑性能和耐磨性,并分析涂层的磨损机制。结果表明:所有涂层防滑性能随着速度和载荷的增加而下降,在相同条件下WC涂层的防滑性能最好,但Al2O3-13%Ti O2涂层耐磨性要好于WC涂层;所有涂层磨损率均随载荷和速度增加呈现上升趋势,Al2O3-13%Ti O2涂层磨损机制以黏着磨损和层片剥落为主,而裂纹扩展引起的脆性断裂则主导了WC涂层的磨损机制。     

纳米α-Al2O3颗粒弥散强化镍基复合涂层的耐磨性能研究

将纳米α-Al2O3颗粒或Ni包裹的纳米α-Al2O3复合粉和镍基粉用湿法混合，采用火焰热喷涂工艺制备了复合涂层，用磨粒磨损试验机进行磨损试验，研究了纳米α-Al2O3的体积分数、粒径和是否预先进行包裹处理对涂层喷焊性和耐磨粒磨损性能的影响。结果表明，纳米α-Al2O3以包裹形式加入能有效改善弥散相与Ni基涂层的相容性，相应涂层的耐磨性优于未包裹处理；当纳米Al2O3的体积分数为2％时，涂层的耐磨性能最好，为Ni基涂层的2倍多；在相同的体积分数下，随着涂层中弥散强化相尺寸的减小，涂层的耐磨性提高。     

Ni-P-金刚石化学复合镀层的耐磨性

研究了Ni-P镀层、Ni-P-纳米金属石及Ni-P-微米金刚石复合镀层在不同的热处理温度、载荷及金刚石含量下的耐磨性，并分析了复合镀层提高基质金属耐磨性的机理。结果表明：三种镀层的磨损量均随着热处理温度的提高而下降，并在400℃时达到最小值；载荷增加，磨损量增大，在不同热处理温度及载荷下，Ni-P-微米金刚石复合镀层均显示出最好的耐磨性。当微米金刚石加入量在4-8g/L时，镀层的耐磨性最好。复合镀层提高耐磨性的原因在于复合粒子在基质金属表面形成突起，起到了支撑载荷、避免粘着磨损及减小摩擦系数的作用。     

快速砂型铸造用模具表面耐磨涂层的研究

研究适合快速砂型铸造用模具的表面涂层材料,该涂层材料由环氧树脂CYD-128、稀释剂660A和固化剂组成,并添加一定量的微米级Al2O3颗粒。在WTM-1E微型磨损实验机上研究该涂层的耐磨性能,并用扫描电镜和原子力显微镜分析磨损后的表面形貌。结果表明:随Al2O3颗粒含量的增加,复合涂层的摩擦因数逐渐增大,磨损率逐渐降低,当Al2O3颗粒质量分数为5%时,磨损率最低;随Al2O3颗粒含量的增加,复合涂层的磨损机制由黏着占主导逐渐转变为犁削沟占主导;采用该涂层材料处理后的快速砂型铸造用模具具有一定的耐磨性。     

镍-磷-纳米Al2O3复合镀层的摩擦学性能

用化学镀的方法制备了镍-磷-纳米Al2O3复合镀层，研究了热处理温度对镀层硬度和磨损性能的影响，并与二元镍-磷镀层以及镍-磷-Al2O3复合镀层进行了性能对比。结果表明：含有纳米Al2O3微粒的复合镀层具有更高的硬度和耐磨性，经400℃处理后的镀层耐磨性最好。     

混粉工艺对纳米Al2O3复合涂层组织和性能的影响

首次将纳米Al2O3作为弥散增强相应用于热喷涂领域中，先将其与Ni基自由熔性合金粉制成复合粉末，然后用氧－乙炔焰热喷焊工艺制备出复合涂层。研究了不同分散剂、液体介质、混合方式等对涂层耐磨性能的影响。结果表明，最佳工艺得到的复合涂层其耐磨性为单纯涂层的2倍。     

Al2O3/TiC纳米复合刀具材料的力学性能与增韧强化机理

利用热压烧结工艺，制备成功Al2O3／TiC纳米复合陶瓷刀具材料。与同组分的微米级刀具材料相比，其断裂韧度和抗弯强度分别提高74．5％和23．5％。SEM观察表明，Al2O3／TiC纳米复合陶瓷刀具材料的断裂方式主要是穿晶断裂，材料的断口处存在大量的晶粒拔出。TEM观察到Al2O3／TiC纳米复合材料中有典型的内晶结构。     

电泳-电镀沉积制备纳米Al_2O_3颗粒增强镍基复合镀层的耐磨性能

先采用电泳沉积工艺在铜基体上均匀沉积了粒径为20 nm的Al2O3涂层,然后采用电镀技术在Al2O3涂层中沉积金属镍,得到具有较高含量的纳米Al2O3增强镍基复合镀层;用扫描电镜及附带的能谱仪分析了镀层的表面形貌及成分,研究了镀层在干摩擦条件下的摩擦磨损性能,并对其磨损机理进行了探讨.结果表明:相比于纯镍镀层,纳米Al2O3颗粒增强镍基复合镀层的表面更加平整光滑,组织更加致密均匀;镀层中纳米Al2O3颗粒含量对镀层耐磨性能具有显著影响,当其体积分数约为30%时,镀层的耐磨性能最好.     

纳米耐磨和减摩复合镀层的研究

分析了将纳米三氧化二铝(Al2O3)和聚四氟乙烯(PTFE)颗粒加入常规电刷镀液中制备纳米耐磨和减摩复合镀层的组织、显微硬度、耐磨性和摩擦因数。结果表明：纳米颗粒的加入使复合镀层组织明显细化和致密。随着纳米Al2O3颗粒含量的增加，复合镀层的显微硬度和耐磨性有明显的提高，纳米PTFE的加入有助于减少复合镀层的摩擦因数。     

不同润滑条件对纳米Al2O3改性UHMWPE摩擦磨损性能的影响

用MPV 2 0 0型摩擦磨损试验机对纳米Al2 O3改性超高分子量聚乙烯 (UHMWPE)塑料合金材料在不同润滑条件下 (干摩擦、水润滑 )进行了摩擦学性能测定 ,分别考察了载荷、速度以及运行时间等对材料摩擦学性能的影响。为纳米Al2 O3改性超高分子量聚乙烯塑料的实际应用提供理论指导     

镀液中La_2O_3含量对Ni-W-La_2O_3复合镀层组织和性能的影响

本文对在镀液中添加不同含量La2O3微粒对Ni-W-La2O3复合镀层组织和性能的影响进行研究。结果表明,镀液中La2O3微粒含量为4 g/L时,Ni-W-La2O3复合镀层组织均匀致密、表面平整,硬度高,耐高温和耐腐蚀性能好。     

润滑油中加入纳米氧化铝对缸套-活塞环摩擦副摩擦磨损特性的影响

在普通CD40润滑油中加入纳米氧化铝，研究了在不同载荷条件下对缸套活塞环摩擦副摩擦磨损特性的影响；用铁谱仪对试验油样进行了磨粒分析；用原子力显微镜对缸套试样表面的微观形貌进行了测试；用LAS-3000型表面分析系统对磨损表面进行了成分分析。结果表明：缸套活塞环摩擦副在含纳米氧化铝的润滑油作用下，表现出优越的抗摩减磨性能，其效果随栽荷的增大而增强；在高载荷作用下缸套试样表面形貌有了明显的改观，减小了摩擦阻力，降低了摩擦因数。     

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。     

Study of abrasive wear resistance of detonation coatings made of mechanically alloyed powders Ti-Al-B

Abrasive wear resistance of detonation composite coatings Ti-Al-B of different structures is studied. It is found that the coating having an intermetallide matrix with solid-phase inclusions of titanium boride and oxides exhibits the best characteristics. The coating with microstructure based on an occasional mixture of comparatively soft intermetallide and nitride phases with the solid component represented only by borides has the lowest abrasive wear resistance.     

Structure and wear resistance of electron-beam nitrous coatings

The paper deals with the study of the tribological properties of nitrogen-containing austenite coatings deposited by electron-beam facing during abrasive wear and the sliding friction of a VK6 hard alloy indentor. The abrasive wear resistance of the nitrous coatings deposited by the electron-beam facing of steel 60Kh24AG16 powder in quartz sand is lower than that of the steel 65G coatings after hardening; it increases with increasing mass share of the filler. At contents of nitrided ferrovanadium of 10?C30 wt % the abrasive wear rate increases by 30?C50%, respectively. It is found that under a certain load applied to the VK6 ball indentor the friction coefficient and the shear resistance of the surface layer diminish. It is shown that under heavy specific loads applied to the ball indentor the nitrous coating faced from steel 60Kh24AG16 powder and composite nitrous coatings have wear resistance exceeding that of steels 110G13 and Kh18N10 by more than two and seven times, respectively. Based on the results of structural studies an explanation of the observed behavior of the nitrous coatings is proposed.     

Ni-P-PTFE化学复合镀层的耐磨性能研究

制备了Ni-P-PTFE化学复合镀层,在MM-200型磨损试验机上研究了PTFE加入量、热处理温度和载荷对复合镀层摩擦因数和磨损量的影响。结果表明:镀层摩擦因数在PTFE加入量为8mL/L时最小,同时镀层磨损量在此时也最小;在不同热处理温度下,Ni-P-PTFE复合镀层表现出较好的耐磨性和较小的摩擦因数;当载荷超过98N后,镀层的摩擦因数增大;随着载荷的增大,镀层的磨损量增大。     

Microstructure and Tribological Properties of a HfB<Subscript>2</Subscript>-Containing Ni-Based Composite Coating Produced on a Pure Ti Substrate by Laser Cladding

A HfB₂-containing Ni-based composite coating was fabricated on Ti substrates by laser cladding, and its microstructure and tribological properties were evaluated during sliding against an AISI-52100 steel ball at different normal loads and sliding speeds. The morphologies of the worn surfaces were analyzed by scanning electron microscopy (SEM) and three-dimensional non-contact surface mapping. The results show that wear resistance of the pure Ti substrate and NiCrBSi coating greatly increased after laser cladding of the HfB₂-containing composite coating due to the formation of hard phases in the composite coating. The pure Ti substrate sliding against the AISI-52100 counterpart ball at room temperature displayed predominantly adhesive wear, abrasive wear, and severe plastic deformation, while the HfB₂-containing composite coating showed only mild abrasive wear and adhesive wear under the same conditions.     

Wear study of Ni–WC composite coating modified with CeO2

In the present investigation, Ni–WC composite powder was modified with the addition of CeO₂ in order to form a new composition of Ni–WC–CeO₂. The Ni–WC and Ni–WC–CeO₂ compositions were used for coating deposition by high-velocity oxy-fuel (HVOF) spraying process so as to study the effect of CeO₂ addition on microstructure, distribution of various elements, hardness, formation of new phases, and abrasive wear behavior. Further, the effect of load, abrasive size, sliding distance, and temperature on abrasive wear behavior of these HVOF-sprayed coatings was investigated by response surface methodology. To investigate the abrasive wear behavior of HVOF-sprayed coatings four factors such as load, abrasive size (size in micrometers), sliding distance (meters), and temperature (°C) with three levels of each factor were investigated. Analysis of variance was carried out to determine the significant factors and interactions. Investigation showed that the load, abrasive size, and sliding distance were the main significant factors while load and abrasive size, load and sliding distance, abrasive size and sliding distance were the main significant interactions. Thus an abrasive wear model was developed in terms of main factors and their significant interactions. The validity of the model was evaluated by conducting experiments under different wear conditions. A comparison of modeled and experimental results showed 4–9% error. The abrasive wear resistance of coatings increases with the addition of CeO₂. This is due to increase in hardness with the addition of CeO₂ in Ni–WC coatings.