CrNiMo钢在不同氧气含量气氛中的高温摩擦磨损性能

利用QG-700型摩擦磨损试验机,研究与H96黄铜配副的CrNiMo在不同氧气含量环境中的高温摩擦磨损性能,并利用扫面电镜对磨损表面进行表征。结果显示,在较低速度和载荷条件下,气氛环境中氧气含量的增加对与黄铜配副的CrNiMo钢摩擦磨损性能影响较小;在较高速度和载荷条件下,CrNiMo钢摩擦因数与磨损率随气氛环境中氧气含量的增加而减小。随气氛中氧气含量的增加,在摩擦接触表面形成不同的表面膜,使CrNiMo钢的磨损机制发生变化,由黏着磨损为主转变为黏着磨损和氧化磨损共同作用然后到氧化磨损。     

氮/氧混合气氛环境下钢/铜摩擦副摩擦学性能研究

应用QG-700型高温气氛摩擦磨损试验机,研究了常温下CrNiMo钢/黄铜配副在不同氮/氧混合气氛比例条件下的干滑动摩擦磨损性能,利用扫描电子显微镜(SEM)、EDAX能谱仪(EDS)和X射线光电子能谱仪(XPS)分析其磨损机制。试验结果表明:随着氮/氧混合气氛中氧气气氛比例的增加,销试样磨损率和配副的摩擦因数整体均呈现降低趋势;磨损机制逐渐由黏着磨损和磨粒磨损向氧化磨损、磨粒磨损和黏着磨损共同作用机制转变;摩擦表面生成铁和铜的氧化物,且氧化物的成分随着氧气含量不同而有所不同。     

CrNiMo钢腐蚀环境中的摩擦学性能研究

以CrNiMo钢和H96黄铜配副,研究了CrNiMo钢在室温蒸馏水润滑环境和H2SO3溶液性环境中的摩擦学性能.采用扫描电子显微镜(SEM)和能谱仪(EDS)对磨损表面进行表征.结果表明:在常温蒸馏水润滑条件和H2SO3溶液腐蚀条件下,摩擦因数均随滑动速度的增加而逐渐减小,而随接触压力的变化较小;H2SO3溶液腐蚀条件下的腐蚀质量损失随腐蚀时间的增加而增大,但其远小于试样的磨损质量损失;H2SO3溶液腐蚀条件下试样的磨损质量损失远大于蒸馏水润滑条件下的磨损质量损失.     

二氧化碳气氛下钢铜摩擦副摩擦磨损特性研究

应用MMS-1G销盘式高温高速摩擦磨损试验机,研究了二氧化碳气氛条件下CrNiMo钢/H96黄铜配副的干滑动摩擦磨损特性。结果表明:摩擦因数随着载荷和速度的增加而减小;磨损率随着载荷和速度的增加而增加,在逐步增加速度与载荷的过程中,存在着摩擦磨损机制的转变,CrNiMo钢的磨损机制主要表现为粘着磨损和磨粒磨损。     

不同环境气氛对高速干滑动钢/铜摩擦副磨损机制的影响

利用MMS-1G型高温高速销-盘摩擦磨损试验机,以钢/铜摩擦副为研究对象,研究了不同环境气氛对高速干滑动钢/铜摩擦副磨损机制的影响,应用扫描电子显微镜(SEM)、能谱分析仪(EDS)对销试样磨损表面进行分析。结果表明:随着pv值的增加,氧气条件下的磨损机制由粘着磨损转变为氧化磨损;氮气条件下的磨损机制由粘着磨损转变为金属流变和磨粒磨损。氮气气氛条件下的摩擦因数和磨损率均高于氧气气氛条件下的摩擦因数和磨损率。     

不同湿度环境中钢/铜配副摩擦磨损性能研究

应用QG-700型高温气氛摩擦磨损试验机研究了CrNiMo钢/黄铜配副在不同环境湿度条件下的滑动摩擦磨损性能,利用三维形貌轮廓仪、EDAX能谱分析仪(EDS)分析了其磨损机制。结果表明:随着环境气氛湿度的增加,配副的摩擦因数、销/盘试样磨损率和摩擦温度均呈降低趋势,摩擦学性能得到改善。销试样的磨损机制主要为黏着磨损,环境湿度的增大弱化了配副材料的黏着磨损。     

高温不同气氛环境中的CrNiMo钢磨损表面SEM和XPS分析

在200 ℃温度条件下,分别在氧气和氮气气氛环境中,以 CrNiMo 钢销试样和 H96 黄铜盘配副,在QG-700型销盘摩擦试验机上进行了摩擦磨损试验.利用 SEM 和 XPS 对 CrNiMo 钢磨损表面进行了表征.结果表明,在2种气氛环境中,都发生了粘着磨损;在氧气气氛环境和较低载荷条件下,粘着较氮气气氛环境中的严重,且磨损表面有 CuO存在,而在氮气气氛环境中,表面粘着物主要为单质铜.     

接触压力对碳滑板/铜接触线载流摩擦磨损性能的影响

控制电流为250 A,滑动速度为160 km/h,在接触压力50,70,90,110,130 N下,在环-块式载流摩擦磨损试验设备上进行接触压力对碳滑板/铜接触线载流摩擦磨损性能的影响试验,用光学显微镜对滑块的磨损形貌进行观察.结果表明:随着接触压力的减小,滑块的磨损形貌由以较光滑磨损面为主过渡到以受电弧飞溅影响磨损面和多麻坑磨损面为主,主要磨损形式由磨粒磨损过渡到电弧烧蚀磨损,摩擦因数的过渡阶段逐渐明显,稳定阶段的摩擦因数逐渐增大;碳滑板的磨损率随着试验的进行进入稳定期,稳定期磨损率随着接触压力的增加先减小后增加,呈“U”形分布;接触压力的增加可以降低电弧功率和离线率;从碳滑板的磨损率和载流稳定性综合考虑,90 N为最佳接触压力.     

氧气气氛条件下钢铜摩擦副摩擦磨损特性研究

利用MMS-1G销盘式高温高速摩擦磨损试验机,研究了氧气气氛条件下CrN iMo钢/H96黄铜配副的干滑动摩擦磨损特性,并分析了磨损机制,结果表明:纯氧气气氛条件下,摩擦因数随着载荷和速度的增加而减小;磨损率随着载荷和速度的增加而增加。在逐步增加速度与载荷的过程中,存在着摩擦磨损机制的改变。CrN iMo钢磨损失效机制主要表现为氧化磨损、剥落磨损、粘着磨损和磨粒磨损。     

摩擦条件对磁轨制动器极靴材料与钢轨材料间摩擦因数的影响

将磁轨制动器极靴用铸造Q235B钢和油淬硬化45钢组成销-盘摩擦副进行摩擦试验,研究了滑动速度(10～100 km·h-1)、法向载荷(10～80 N)和润滑条件(干摩擦、水润滑)对摩擦因数和磨损机制的影响.结果表明:随着滑动速度的增大,摩擦副的摩擦因数均在3s内达到稳定;稳定摩擦因数随滑动速度的增大先增大后减小,但变...     

PCrNiMo材料摩擦磨损特性研究

采用自制的销盘式干滑动摩擦磨损试验机，研究了不同硬度炮钢材料PCrNiMo自配副时的摩擦磨损特性。研究结果表明：材料的磨损率随着速度、载荷的增加而增大，摩擦因数随着速度、载荷的增加而减小；低速低载条件下，接触表面以磨粒磨损为主，而在高速、高载条件下，接触表面以粘着磨损形式为主。     

柱塞泵配流副滑摩界面摩擦磨损及热力耦合分析

针对轴向柱塞泵配流副滑摩过程中由摩擦温升所引起的摩擦磨损问题,建立配流副轴对称非稳态热传导方程,利用ABAQUS有限元软件进行配流副摩擦磨损及热力耦合特性分析,并利用端面摩擦磨损试验机进行试验验证。结果表明:在滑摩初期,相比于中低压力,高压力工况更易发生磨粒磨损;随着滑摩进行,材料表面粗糙峰被磨平,加之温度上升,材料强度下降,高转速取代高压力成为接触面温度和摩擦系数增大的主要影响因素,此时的磨损机制主要为黏着磨损;在滑摩过程中,外径出现了应力集中现象,且接触压力高于内径;转速及压力对配流副摩擦温升及磨损特性的影响是非线性的,在相同PV值下,转速比压力的影响更为显著。     

Dry sliding wear behaviour of cast high strength aluminium alloy (Al–Zn–Mg) and hard particle composites

This paper describes the results of dry sliding wear tests of aluminium alloy (Al–Zn–Mg) and aluminium (Al–Zn–Mg)–10, 15 and 25 wt.% SiCp composite was examined under varying applied pressure (0.2 to 2.0 MPa) at a fixed sliding speed of 3.35 m/s. The sliding wear behaviour was studied using pin-on-disc apparatus against EN32 steel counter surface, giving emphasis on the parameters such as coefficient of friction, rise in temperature, wear and seizure resistance as a function of sliding distance and applied pressure. It was observed that the wear rate of the alloy was noted to be significantly higher than that of the composite and is suppressed further due to addition of silicon carbide particles. The temperature rise near the contacting surfaces and the coefficient of friction followed reversed trend. Detailed studies of wear surfaces and subsurface deformation have been carried out. The wear mechanism was studied through worn surfaces and microscopic examination of the developed wear tracks. The wear mechanism strongly dictated by the formation and stability of oxide layer, mechanically mixed layer (MML) and subsurface deformation and cracking. The overall results indicate that the aluminium alloy–silicon carbide particle composite could be considered as an excellent material where high strength and wear resistance are of prime importance.     

Ti6Al4V/WC-Co干摩擦性能研究

利用Optimal SRV高温摩擦磨损试验机,研究干摩擦条件下钛合金(Ti6Al4V)对硬质合金(WC-Co)的摩擦学性能.研究了载荷、温度与滑动速度对摩擦过程的影响,通过磨损区微观形貌表征分析了磨损机理.结果表明:Ti6Al4V与WC-Co的摩擦系数波动剧烈,产生了严重的黏滑摩擦,且随着载荷、温度与滑动速度的增加,黏...     

M35与GCr15干摩擦磨损性能的研究

在HT-1000型高温摩擦磨损试验机上,对M35高速钢进行干滑动摩擦磨损试验,利用SEM(扫描电镜)观察并分析摩擦面磨损形貌及磨损机理。结果表明,M35高速钢在与GCr15滚动轴承合金钢配副干摩擦条件下,随着速度的增加,摩擦因数先降低后升高,然后再降低。当摩擦热累积达到一定值后,摩擦表面产生严重塑性变形和化学变化,摩擦副表面产生氧化磨损、粘着磨损、磨粒磨损和犁沟磨损,形成转移润滑膜,此时摩擦因数较低,磨损率也相对较低。     

Transitions in the Friction and Wear of Carbons and Graphites Sliding Against Themselves

The friction and wear properties of various carbons and graphites have been measured during sliding against themselves in air. Many materials exhibit sudden and large increases in both friction and wear at a critical combination of load, speed, and temperature, and the effects are most pronounced for electrographites and natural graphites. The sliding conditions at the transition are associated with a critical temperature of the contacting asperities, and the magnitude of this temperature, approximately 150–185 C for graphitic materials, has been estimated both directly and by application of flash-temperature theory. The phenomena accompanying the transitions are very similar to those occurring during dusting of carbon brushes at high altitudes, and a similar explanation is invoked in terms of the adsorption of water vapor and oxygen. The critical combinations of loads and speeds required to initiate the transition are much more severe than those normally encountered during the operation of carbon brushes and bearings.     

Effects of Contact Pressure and Sliding Speed on the Unlubricated Friction and Wear Properties of Zn-15Al-3Cu-1Si Alloy

The unlubricated friction and wear properties of Zn-15Al-3Cu-1Si alloy were studied over a range of contact pressure (1–5 MPa) and sliding speed (0.5–2.5 ms^?1) for a sliding distance of 2,500 m using a block-on-disc type test machine. It was observed that as the contact pressure increased, the friction coefficient of the alloy decreased but its working temperature, surface roughness, and wear volume increased. Sliding speed had no significant effect on the friction coefficient of the alloy but increased its working temperature, surface roughness, and wear volume. It was also observed that the formation of a hard and brittle surface layer had a great influence on the wear behavior of the experimental alloy. The hardness and thickness of this layer increased with increasing contact pressure and sliding speed. However, contact pressure was found to be much more effective on the hardness of the surface layer of this alloy. Both adhesion and abrasion were observed to be the dominant wear mechanisms for the alloy under the given sliding conditions. The results obtained from the friction and wear tests are discussed in terms of the test conditions and microstructural changes that take place during sliding.     

45钢的摩擦磨损特性实验研究

采用自制的销盘式干滑动摩擦磨损试验机,研究了45钢配副的摩擦磨损特性.结果表明:材料的磨损率随着速度、载荷的增加而增大;摩擦系数随着速度、载荷的增加而减小.磨损机理主要为磨粒磨损和粘着磨损.     

Effect of temperature on friction and wear of prehardened tool steel during sliding against 22MnB5 steel

Abstract

Mechanical components in tribological systems exposed to elevated temperatures are gaining increased attention since more and more systems are designed to operate under extreme conditions. In hot metal forming, the effect of temperature on friction and wear is especially important since it is directly related to process economy (tool wear) and quality of the produced parts (friction between tool and workpiece). This study is therefore focused on fundamental understanding pertaining to the tribological characteristics of prehardened hot work tool steel during sliding against 22MnB5 boron steel. The tribological tests were carried out using a high temperature reciprocating sliding friction and wear tester under a normal load of 31 N (corresponding to a contact pressure of 10 MPa), a sliding speed of 0·2 m s^?1 and temperatures ranging from 40°C to 800°C. It was found that friction coefficient and specific wear rate decreased at elevated temperature because of formation of compacted wear debris layers on the surfaces.     

Tribological behavior of Cu20%Nb and Cu15%Cr in situ composites under dry sliding conditions

The tribological behavior of Cu20%Nb and Cu15%Cr in situ composites was studied on a pin-on-disk tester. Composite pins were slid against a hardened AISI 52100 steel disk under dry ambient conditions. Comparison of coefficient of friction, wear rate and bulk temperature was made between the two composites in terms of effects of normal pressure and sliding speed. Microstructural changes in the composites due to sliding were studied and correlated with the change of tribological behavior. The wear rate increased with increasing normal pressure and decreased with increasing sliding speed in the studied range of normal pressure (0.06–0.56 MPa) and sliding speed (2.50–5.83 m s⁻¹) for both composites. Cu20%Nb showed a much better wear resistance and a lower coefficient of friction than Cu15%Cr. The coefficient of friction slightly increased for Cu20%Nb and slightly decreased for Cu15%Cr with increasing normal pressure. The coefficient of friction for both composites decreased with increasing sliding speed. The bulk temperature was higher and subsurface deformation layer thickness was larger for Cu15%Cr than for Cu20%Nb. Both of them increased with increasing normal pressure and sliding speed. Scanning electron microscopy analysis showed plastic deformation flow on the wear surface at an early stage for both composites. However, the formation of a surface film led Cu20%Nb composite to reach a steady state much sooner and therefore to have a lower wear rate than Cu15%Cr.