载荷对PTFE/AlSi10Mg复合材料摩擦磨损行为的影响

采用选区激光熔化(SLM)、浸渗和真空烧结工艺制备了以AlSi10Mg为基体的多孔骨架填充聚四氟乙烯(PTFE)的自润滑复合材料。采用往复式Bruker UMT-3摩擦试验机研究了速度为5mm/s、不同载荷下复合材料的摩擦磨损性能,并采用SEM、EDS等对其成分、结构以及摩擦学行为进行了研究。结果表明,复合材料的平均摩擦因数和磨损率随着载荷的增加呈现先增大后减小的趋势;复合材料的摩擦稳定性主要由存储在骨架中的PTFE决定。其摩擦机制主要是在载荷的作用下,当磨擦表面发生磨损时,骨架中的PTFE将磨屑捕获,形成完整的PTFE润滑层,并且发生膜的转移,从而增加了复合材料的摩擦学稳定性。     

两步法制备TiO2/(PTFE+石墨)微弧氧化复合膜层及其摩擦磨损行为

目的 提高钛合金钻杆的耐磨性能。方法 先对钛合金钻杆表面进行微弧氧化处理,然后再对微弧氧化层进行（PTFE+石墨）复合处理,得到（PTFE+石墨）复合膜层。利用扫描电镜（SEM）观察TiO2/(PTFE+石墨)复合膜层的表面形貌,通过能谱（EDS）分析膜层元素的含量,用X射线衍射（XRD）分析复合膜层的相组成,用多功能摩擦磨损试验机测试膜层的摩擦磨损性能,并利用三维显微镜（白光干涉仪）观察微弧氧化层磨损后磨痕的三维形貌。结果 PTFE和石墨进入钛合金微弧氧化层的微孔中,并在表面形成薄薄的一层PTFE+石墨复合涂层。膜层中主要含有Ti、O、Si、Al、P、V、C、F等元素,其中碳和氟质量分数分别达到9.96%和25.53%。XRD分析结果表明,TiO2/(PTFE+石墨)复合膜层中除了锐钛矿型TiO2和金红石型TiO2外,还含有PTFE和石墨。TiO2/(PTFE+石墨)复合膜层的摩擦系数为0.19,磨痕宽度和深度分别为210 μm和1.5 μm,相对耐磨性达到18.73。复合膜层的磨痕没有明显的铧犁沟,磨痕比较平整。与TC4钛合金基体相比,TiO2/(PTFE+石墨)复合膜层的耐磨性得到了明显提高。TiO2/(PTFE+石墨)复合膜层的磨损以磨粒磨损为主,伴有粘着磨损。结论 采用两步法对钛合金进行TiO2/(PTFE+石墨)复合处理后,可有效提高钛合金的耐磨性能。     

硬质薄膜与自润滑织物衬垫对磨的摩擦磨损性能研究

目的 提高钛合金与自润滑织物衬垫对磨的耐磨性.方法 采用多弧离子镀在TC4钛合金表面制备TiN和CrAlN硬质薄膜,利用扫描电镜、X射线衍射仪、纳米压痕仪、销-盘摩擦磨损试验机、白光干涉扫描轮廓仪测试分析薄膜的形貌、结构、硬度、弹性模量、摩擦磨损性能和磨痕形貌.结果 在相同的测试条件下,TC4钛合金与自润滑织物衬垫对磨时,能更快地进入稳定摩擦阶段,且平均摩擦系数最低,仅为0.12;TiN薄膜进入稳定摩擦阶段所用时间和摩擦系数较TC4钛合金稍有增加;而CrAlN薄膜进入稳定摩擦阶段的用时最长且平均摩擦系数最大.测量摩擦磨损后自润滑织物衬垫磨痕的二维轮廓发现,当与CrAlN薄膜对磨时,自润滑织物衬垫的磨痕深度最大,但磨损率最低,这主要是软质织物衬垫的不均匀磨损引起的.进一步分析发现,所有的试验销表面均形成了转移膜,但CrAlN薄膜表面形成的转移膜最薄,从而导致其摩擦系数最大,磨损率最低.深入分析自润滑织物衬垫磨痕形貌发现,与TC4钛合金对磨的自润滑织物衬垫的磨痕表现为磨粒磨损和纤维束的破损;与TiN薄膜对磨的自润滑织物衬垫的磨痕表现为区域损失和表面不规则的凹痕;与CrAlN薄膜对磨的自润滑织物衬垫的磨痕中纤维束破损严重.结论 与自润滑织物衬垫对磨后,钛合金以及硬质薄膜表面均形成转移膜,CrAlN薄膜表面转移膜最薄,与之对磨的自润滑织物衬垫的磨损率最低.     

自润滑纤维织物复合材料摩擦学性能研究

目的研究MoS_2和石墨填充对自润滑纤维织物复合材料摩擦学性能的影响。方法采用玄武三号栓-盘式摩擦磨损实验机,研究了石墨和MoS_2填充PTFE/棉纤纤维织物在不同载荷条件下的摩擦磨损性能,并采用扫描电镜观察了纤维织物复合材料的磨损表面和微观结构。结果在较低载荷下,填充5%MoS_2可以更有效地降低PTFE/棉纤纤维织物复合材料的磨损率;在较高载荷下,填充10%石墨可以更有效地降低PTFE/棉纤纤维织物复合材料的磨损率。载荷为219.52 N时,5%MoS_2填充PTFE/棉纤纤维织物复合材料的磨损率由未填充的1.28×10~(-14) m~3/(N·m)降低到0.61×10~(-14) m~3/(N·m),降低了50%;10%石墨填充PTFE/棉纤纤维织物复合材料的磨损率由1.28×10~(-14) m~3/(N·m)降低到0.91×10~(-14) m~3/(N·m),降低了28%。结论石墨和MoS_2填充在摩擦过程中减轻了磨粒的嵌入和切削作用,阻碍了复合材料的磨损,提高了PTFE/棉纤纤维织物复合材料的耐磨性能。     

Ni-P/Ti/DLC多层膜的摩擦磨损性能

目的研究摩擦速度、载荷及加热温度对Ni-P/Ti/DLC多层膜摩擦磨损性能的影响。方法用化学镀镍磷工艺在模具钢基体表面镀上Ni-P层作切削层,采用过滤阴极真空电弧(FCVA)技术分别沉积Ti过渡层和DLC保护层。通过摩擦磨损实验,评价该多层膜的摩擦磨损性能。利用纳米压痕测试和拉曼光谱检测,研究该多层膜在不同加热温度下的硬度、弹性模量和结构成分。利用扫描电镜及表面轮廓仪分别对该多层膜的磨痕形貌和横截面轮廓进行分析。结果随着摩擦速度的增大,Ni-P/Ti/DLC多层膜的摩擦系数呈下降趋势,磨损率和磨损体积呈先减后增的趋势。不同载荷下的摩擦系数变化幅度较小,磨损率和磨损体积随着载荷的增大呈增加的趋势。随着加热温度的升高,摩擦系数呈下降趋势,磨损率和磨损体积呈先增后减的趋势。此外,随着加热温度的升高,多层膜表层DLC膜中石墨相逐渐增多,硬度和弹性模量随之呈先增后减的趋势。结论较高摩擦速度下,多层膜表层DLC膜石墨化趋势增强,摩擦系数变化幅度较大,且表面磨痕宽度和深度显著增加,磨损加剧。多层膜中软质的Ti金属层和硬质的DLC层,能有效提高多层膜在高载荷下的摩擦磨损性能。随着加热温度的升高,多层膜表层DLC膜中石墨相逐渐增多,摩擦过程更易生成转移膜。     

金属和陶瓷配副件条件下TiN薄膜的摩擦学特性

多弧离子镀TiN薄膜具有广泛的应用.采用多弧离子镀技术在不锈钢衬底表面沉积了TiN薄膜.用显微硬度计测试了TiN薄膜的硬度,用往复球-盘式摩擦磨损试验机评价了在GCr15和Si3N4两种不同配副件及空气中干摩擦条件下TiN薄膜的摩擦学性能,用表面轮廓仪测试了磨痕处的磨痕轮廓,用配有能谱仪(EDS)的扫描电镜(SEM)和X射线光电子能谱(XPS)观察和测试了磨痕形貌和磨痕处主要化学元素组成,用金相显微镜观察了配副件磨损表面形貌.结果表明:在不同配副件条件下,TiN薄膜的摩擦因数随速度和载荷的增加均出现了降低的趋势.而在相同速度和载荷下,以GCr15为配副件时TiN薄膜的摩擦因数小于以Si3N4为配副件时的摩擦因数.以Si3N4为配副件时TiN薄膜主要表现为磨粒磨损.以GCr15为配副件时TiN薄膜几乎没有磨损,而配副件GCr15主要表现为磨粒与粘着磨损.     

A356铝合金微弧氧化膜微动磨损行为的研究

采用微弧氧化（MAO）在A356铝合金表面制备MAO膜,利用球-平面接触在SRV-V微动摩擦磨损机上探究变载荷和位移下微弧氧化对A356微动磨损机理的影响。结果表明：MAO膜由疏松层和致密层构成,其均匀性、致密性和结合力良好。MAO膜的摩擦系数、磨损率均低于A356,MAO膜减摩耐磨性较好。随位移增加MAO膜的摩擦耗散能系数低于A356,MAO膜能提升A356微动磨损过程的稳定性。载荷增加时A356磨损机制为磨粒磨损-粘着磨损,伴随犁削和疲劳剥层; MAO膜磨损机制为磨粒磨损-粘着磨损和疲劳剥落。位移增加时A356磨损机制为粘着磨损和疲劳剥落,伴随微犁削;MAO膜磨损机制为粘着磨损和疲劳剥层-粘着磨损和磨粒磨损。A356的磨痕内聚集Fe、O元素,存在材料转移和氧化磨损;MAO膜磨痕内聚集Fe元素,存在材料转移。     

耐指纹表面处理产品微摩擦性能及机制研究

为了研究耐指纹产品的微摩擦机理,提高其耐磨性能,以传统的纯锌镀层和新兴的锌铝镁镀层耐指纹产品为研究对象,采用微摩擦线性往复试验、激光共聚焦显微镜观察等手段,模拟耐指纹产品真实的摩擦环境,观察磨痕的三维形貌,研究了载荷条件和循环次数对摩擦磨损规律的影响,探究了两种产品的磨损机制。结果表明,锌铝镁镀层耐指纹产品表现出比纯锌镀层产品更好的微摩擦性能;载荷的增加通过产生更多的塑性变形和摩擦热加速了耐指纹膜层的破坏,但对摩擦因数影响不大,而随循环次数的增加,两种耐指纹产品经历了塑性流动、磨粒磨损和剥层磨损等主要磨损机制,其中耐指纹膜层被破坏时的剥层磨损导致了磨痕的迅速扩大;膜层未被磨穿时,锌铝镁镀层耐指纹产品摩擦因数曲线出现的周期性锯齿形源于涂镀时的铺展方向,而曲线中出现的针状凸起应与镀层表面的毛刺有关。     

刀具表面磁控溅射CrN涂层及其耐磨性能研究

目的 提高刀具耐磨性能,延长刀具材料的使用寿命,减小刀具在加工过程中的磨损。方法 采用射频磁控溅射法在高速钢刀具表面沉积CrN涂层,用XRD、FESEM等分析涂层的组织结构与微观形貌,用X射线谱仪（EDS）测量涂层成分含量及其分布,用划痕仪测定膜基结合力,用球-盘磨损仪进行磨损实验。探讨不同摩擦条件下涂层的耐磨性能,探究不同摩擦条件对未镀膜刀具与镀膜刀具摩擦学性能的影响,对比分析摩擦系数、磨痕深度、磨痕宽度随参数变化的规律。结果 磁控溅射制备出结构致密、轮廓清晰、表面平整度趋于光滑的CrN涂层,涂层呈现三角锥形貌,具有明显的CrN(111)择优取向,膜基结合力为31.6 N。磨损试验表明,高载荷条件下（载荷5 N）,未镀膜刀具磨损较严重,磨痕颜色较深,磨痕深度与宽度分别为27.6、980.2 μm,摩擦系数为0.498。镀膜刀具磨痕两侧只有轻微的犁沟和较少的磨屑堆积,表面磨痕颜色较浅,磨损轻微,磨痕深度与宽度分别为2.25、570.8 μm,摩擦系数为0.314。结论 在高速钢刀具表面沉积CrN涂层能显著提高刀具的耐磨性能,刀具在磨损试验中磨痕深度、磨痕宽度和摩擦系数均较小。     

不同基体炭结构的C/C复合材料摩擦表面特性和摩擦磨损机理

与表面镀Cr的40Cr钢配副进行滑动摩擦实验后,在JSM 6360LV扫描电镜上观察6种具有不同基体炭结构的C/C复合材料的磨损表面形貌。结果表明:完全光滑层(SL)炭结构的C/C复合材料摩擦表面在任何载荷下均难以形成完整的磨屑膜;完全粗糙层(RL)炭结构、粗糙层/树脂炭(RL/RC)的材料摩擦表面在低载荷时能形成较厚的磨屑膜,在高载荷时表面摩擦膜均很薄;完全RC结构试样摩擦表面在低载荷时完整、致密,在高载荷时有显著的磨屑膜剥落;RL/SL/RC、SL/RC结构试样在低载荷时的表面摩擦膜薄,而高载荷时,RL/SL/RC材料的基体炭磨损比SL/RC的严重;RL/SL或SL炭在摩擦中的损伤呈现阶梯状磨损形貌,RL炭在摩擦后难以分辨出原始形貌,RC炭在部分摩擦表面则为条纹状磨损形貌;RL/SL/RC、SL/RC结构的C/C复合材料摩擦形貌的稳定性高,材料耐磨性好,在一定载荷范围内有利于降低材料的摩擦因数和体积磨损。     

一种船用低温钢板在干态室温下的往复摩擦特性研究

目的研究新型船用低温钢板的摩擦磨损性能。方法采用UMT-2型多功能摩擦磨损实验机,测试了船用低温钢板在室温干态环境、不同载荷(10、20、30 N)、不同频率(2、5 Hz)下的往复摩擦试验行为。采用光学显微镜(OM)、扫描电子显微镜(SEM)分析了船用低温钢板的磨痕表面形貌,用光学轮廓仪分析了磨损表面轮廓,用EDS对试样磨损表面进行了成分分析。结果随着试验法向载荷从10 N增加到30 N时,船用低温钢板的摩擦系数从0.51逐渐增加到0.63,磨损率先增加后降低,再逐渐增加。在相同载荷下,摩擦系数随着往复频率的提高而降低。载荷为30 N时,往复频率为5 Hz,摩擦2 h后,磨损断面轮廓宽度和深度分别为750μm和3871 nm。接触面从磨粒磨损转向疲劳磨损,接触面出现氧化层、表面硬化层和转移层。结论载荷较低时,船用低温钢磨损主要为氧化磨损和疲劳磨损;载荷增大时,接触面磨损出现疲劳磨损。同等载荷下,摩擦系数会随着移动速度的提高有所下降,接触面在摩擦热作用下形成的金属膜有助于降低表面粗糙度,减小摩擦系数。     

Structure and micro-tribologicai properties of PTFE/Al2O3 micro-assembling film

In order to improve the wear resistance of elastic metallic-plastic thrust bearing pad,micro-assembling PTFE/Al2O3 multi-layer film was developed by alternating radio frequency(RF)magnetron sputtering PTFE and Al2O3 targets.For enhancing the adhesion of the interfaces between PTFE and Al2O3 film,N+ implantation was employed.The structure,mechanical and micro-tribological properties were studied by XPS,X-ray photoelectron spectrometer and atomic force and friction force microscope(AFM/FFM).The results show that the multi-layer consists of Al2O3 component and crystalline PTFE.The hardness of the multi-layer modified by ion implantation is less than that of Al2O3,but its toughness is greatly improved.The friction coefficient of PTFE/ Al2 O3 multi-layer modified by ion implantation is much lower than that of Al2 O3 film,and its resistance to wear is much greater than that of PTFE film.Therefore the wear resistance of elastic metallic-plastic thrust bearing pad is greatly improved.     

Effect of mating surface on the high temperature wear of 253 MA alloy

The wear behaviour of metallic material is influenced by the friction force, which in turn, is governed by the hardness and oxidation kinetics of the mating surface. In view of this, present investigation is undertaken to find the influence of mating surface on the high temperature wear of 253 MA alloy. This alloy is developed for high temperature application. In this work 253 MA alloy is made to slide against two different types of counter face material, namely 100Cr6 steel and PM 1000 alloy, at five different temperatures. 100Cr6 steel gets soften with increase of temperature whereas PM 1000 alloy retains its strength even at high temperature. The friction coefficient and the thickness loss of 253 MA alloy is measured and compared against both variety of mating surfaces as function of temperatures. The morphology of the worn surfaces and the transverse section of the worn surfaces are examined under scanning electron microscope (SEM) to identify the material removal mechanisms. The results showed that the friction coefficient of test material against PM 1000 alloy is around 40% higher than the friction coefficient against 100Cr6 steel. The transverse section of the worn surface showed presence of a transfer layer, mechanically mixed layer and composite layer, which govern the wear behaviour particularly at elevated temperature. The chemical characteristics of these layers are dependent on the test temperature and the counter face material.     

乙烯基酯树脂粘结固体润滑涂层的制备及摩擦学性能

以双酚A型环氧树脂E-51和丙烯酸(AA)为原料合成了乙烯基酯树脂(VER),用红外光谱(FTIR)表征了不同反应时间反应体系中基团的变化情况.用过氧化苯甲酰(BPO)为催化剂,N,N-二甲基苯胺(DMA)为促进剂实现了该树脂的室温固化,并制备了以该乙烯基酯树脂为粘结剂,聚四氟乙烯(PTFE)为固体润滑剂的粘结固体润滑涂层.在CSM栓-盘摩擦试验机上考察了不同聚四氟乙烯添加量对涂层摩擦学性能的影响,分别采用扫描电子显微镜(SEM)和光学电子显微镜分析了润滑涂层和对偶钢球的磨损表面形貌.结果表明:以乙烯基酯树脂为粘结剂的聚四氟乙烯固体润滑涂层具有优异的减摩抗磨性能.     

Structure and micro-tribological properties of PTFE/Al_2O_3 micro-assembling film

1　INTRODUCTIONComparedwithBabbittpadsofthrustbearing ,theelasticmetallic plasticpadspossessthecombina tionofreliablerunning ,excellentperformance ,flexi bleoperation ,convenientinstallationandlongservicelife.Thereforetheelasticmetallic plasticpadsarewidelyemployedinverticalelectricmachinesofhy dropower plants .Polytetrafluoroethylene (PTFE )hasbeenusedasthesurfacematerialoftheelasticmetallic plasticpadsbecauseofitslowfrictioncoeffi cientandelectricalinsulation[1] ;butitsstrengthandwearr…     

Friction and wear characteristics of polymer-matrix friction materials reinforced by brass fibers

This study is an investigation of friction materials reinforced by brass fibers, and the influence of the organic adhesion agent, cast-iron debris, brass fiber, and graphite powder on the friction-wear characteristics. Friction and wear testing was performed on a block-on-ring tribometer (MM200). The friction pair consisted of the friction materials and gray cast iron (HT200). The worn surface layers formed by sliding dry friction were examined using scanning electron microscopy (SEM), x-ray energy-dispersive analysis (EDX), and differential thermal analysis-thermogravimetric analysis (DTA-TAG). The experimental results showed that the friction coefficient and the wear loss of the friction materials increased with the increase of cast-iron debris, but decreased with the increase of graphite powder content. The friction coefficient and wear loss also increased slightly when the mass fraction of brass fibers was over 19%. When the mass fraction of organic adhesion agent was about 10–11%, the friction materials had excellent friction-wear performance. Surface heating from friction pyrolyzes the organic ingredient in the worn surface layer of the friction materials, with the pyrolysis depth being about 0.5 mm. The surface layers were rich in iron but poor in copper, and they were formed on the worn surface of the friction material. When the mass fraction of brass fibers was about 16–20%, the friction materials possessed better wear resistance and a copper transfer film formed on the friction surface of counterpart. Fatigue cracks were also found in the worn surface of the gray cast-iron counterpart, with fatigue wear being the prevailing wear mechanism.     

Tribological property and wear mechanism of undercooled Ni-Pb monotectic alloys

1　INTRODUCTIONMonotecticalloyshaveperfectphysicalandchemicalpropertiesandcanbeusedasself lubricatingmaterials ,electricalcontactmaterials ,superconductingmaterialsetc[13] .However ,itisverydifficulttofabricatemono tecticalloyswithhomogeneousstructuresbyemployingconventionalcasting ,becausetheparentliquiddecompos esquicklyintotwodistinctimmiscibleliquidsintheim miscibilitygap[4 6 ] .Theproblemhasdelayedtheutiliza tionofmonotecticalloysasindustrialmaterialsandsys tematicresearchonthesolidif…     

树脂基摩擦材料耦合机理研究

目的提高树脂基摩擦材料的机械性能和摩擦磨损性能。方法利用纤维的协同耦合效应制备混杂纤维增强材料,通过正交实验法设计配方,探究混杂纤维对摩擦材料性能的影响。借助扫描电镜对磨损表面和磨屑的微观形貌进行分析,使用能谱分析其元素组成,以探究摩擦材料的耦合机理。结果混杂纤维含量从8%增加到10.5%,摩擦材料的洛氏硬度和剪切强度分别维持在50～75 HRB、11.5～16.5 MPa适宜范围内,其中S3试样的洛氏硬度最大,为71 HRB,S4试样的剪切强度最大,为16.1 MPa。混杂纤维的交叉耦合效应决定了摩擦材料的机械性能。碳纤维在接触表面形成一层转移膜,发挥着润滑降温的作用,对摩擦材料的摩擦系数及磨损率均影响最大。结论转移膜的形成可有效缓解热衰退现象。适宜含量的混杂纤维可使摩擦表面形成连续的转移膜,且粒径细小的磨屑可提高转移膜的自洁性,从而降低摩擦材料的磨损率。磨损机理也由磨粒磨损和粘着磨损转变为多种机理综合的磨损形式。