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。     

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.     

溶胀对干摩擦下丁腈橡胶滑动磨损行为的影响

对制备的不同丙烯腈含量的丁腈橡胶试样进行静态浸泡试验,并对溶胀前后的丁腈橡胶试样进行干摩擦条件下的单向滑动磨损试验,分析试样磨损后的表面形貌,揭示溶胀对干摩擦磨损的影响机制。结果表明:溶胀后丁腈橡胶的磨损量增加,受溶胀的影响程度随溶胀时间的增加而增加,随丙烯腈含量的增加而降低;溶胀试验后丁腈橡胶样品在摩擦热的作用下软化现象加剧;随着溶胀时间的增加,磨损形式由剪切撕裂向黏着磨损转变,易切削效应时间和黏着程度随丙烯腈含量的增加而降低;溶胀后丁腈橡胶试样磨损表面可见大量孔洞,而对磨副摩擦轮表面可见转移的橡胶组织,且与溶胀后橡胶样品对磨时摩擦轮表面橡胶组织黏着面积增加。     

电流对黄铜/Al2O3弥散强化铜合金摩擦副摩擦磨损性能的影响

根据列车受电弓系统的实际工况条件,在自制的销-盘式载流摩擦磨损试验机上研究了Al2O3弥散强化铜合金销试样和黄铜（H62）盘试样摩擦副在载流条件下的滑动摩擦磨损性能,试验条件为速度20m/s、载荷0.63MPa、电流25-75A。试验结果表明,电流对黄铜/Al2O3弥散强化铜合金摩擦副的滑动干摩擦行为具有显著影响。随电流的增加,销试样的磨损率增加,摩擦因数增大,试样表层发生了磨粒磨损和粘着磨损。     

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。     

直流磁场条件下GCr15/W18Cr4V摩擦磨损特性研究

大气条件下,在改进的MPV-1500型摩擦试验机上研究不同磁场强度下的GCr15/W18Cr4V配副干滑动摩擦磨损性能,采用扫描电镜(SEM)观察试样磨损后的表面形貌和组织,采用能量分散谱仪(EDS)测定磨损后的表面成分。结果表明:与无磁场条件下相比,有磁场时GCr15钢销的摩擦因数较小,磨损量较低;随磁场强度的增加,摩擦因数有减少的趋势,而磨损量则先急剧降低,至较低值后呈现缓慢下降的趋势;直流磁场吸附磨屑形成三体磨损,是直流磁场减摩耐磨的主要原因。EDS分析表明:在磁场条件下磨损后GCr15钢的磨损表面会生成更多的氧,氧化磨损比例增加。     

载流条件下黄铜/Al2O3/Cu复合材料摩擦副的摩擦磨损性能

采用内氧化法制备了Al2O3/Cu复合材料,以该复合材料为销试样,黄铜(H62)为盘试样进行载流条件下的干滑动摩擦磨损试验,并对销试样摩擦表面进行微观形貌分析.结果表明:磨损率随着电流、速度和载荷的增大而增加,摩擦因数随着电流的增大而增加,随着速度和载荷的增大而减小;电流较小时摩擦表面具有磨粒磨损和粘着磨损的共同特征,电流较大时以粘着磨损为主;在试验条件下,Al2O3/Cu复合材料的抗摩擦磨损性能显著优越于紫铜.     

弹性金属塑料复合材料的摩擦磨损特性研究

在MPX-2000摩擦磨损试验机上，用环盘摩擦副，结合扫描电镜分别评价了弹性金属塑料（EMP）复合材料与钢在油润滑和干摩擦条件下的摩擦磨损特性。结果表明：两种试验条件下，相同滑动速度的摩擦系数随载荷的升高而减小，当载荷为2000N，滑动速度小于3.52m/s时，摩擦系数基于趋于稳定，EMP磨损率随滑动速度和载荷的升高耐增加，但不同试验条件的增幅不高，油润滑下滑动速度小于3.52m/s和干摩擦条件下滑动速度小于1.96m/s时，EMP以微切削，塑性变形和梨沟磨损为主，并在摩擦副两表面形成转移物。     

有无电流工况下钢铝复合轨/受电靴的摩擦磨损特性

利用改进设计的销盘摩擦磨损试验机,研究了用于地铁供电的钢铝复合轨与受电靴在有无电工况下的滑动摩擦磨损性能,对比了磨损量与摩擦因数的变化,观察和分析了微观磨损形貌,分析了其摩擦磨损机制。试验表明:电流对摩擦副的干摩擦滑动行为具有显著的影响,随着电流的增加,钢铝复合轨和受电靴的磨损质量增加,摩擦因数减小,摩擦表面出现粘着磨损、电弧烧蚀、磨粒磨损、疲劳剥落特性。     

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。     

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。     

离子渗硫模具钢的摩擦磨损机理研究

对模具钢5CrNiMo进行低温离子渗硫处理，表现得到了厚约10μm的渗硫层。在MM－200型摩擦磨损试验机上进行了渗硫层干摩擦条件下的摩擦学试验。利用原子力显微镜（AFM）和扫描电镜（SEM）观察了渗硫层的表面、截面与磨痕形貌；利用X射线衍射仪（XRD）分析了渗硫层的相结构；利用扫描俄歇微探针（SAM）分析了表面元素沿深度的分布。渗硫层表面多孔且不平，由纳米尺度的微粒随机叠嵌而成。渗硫层的纳米结构有利于改善其减摩耐磨性能。摩擦磨损结果表明，模具钢渗硫层的摩擦学性能明显优于未渗表面。     

Substrate Effects on the Micro/Nanomechanical Properties of TiN Coatings

Nanoindentation and nanoscratch tests were performed for titanium nitride (TiN) coatings on different tool steel substrates to investigate the indentation/scratch induced deformation behavior of the coatings and the adhesion of the coating–substrate interfaces and their tribological property. In this work, TiN coatings with a thickness of about 500 nm were grown on GT35, 9Cr18 and 40CrNiMo steels using vacuum magnetic-filtering arc plasma deposition. In the nanoindentation tests, the hardness and modulus curves for TiN/GT35 reduced the slowest around the film thickness 500 nm with the increase of indentation depth, followed by TiN/9Cr18 and TiN/40CrNiMo. Improving adhesion properties of coating and substrate can decrease the differences of internal stress field. The scratch tests showed that the scratch response was controlled by plastic deformation in the substrate. The substrate plays an important role in determining the mechanical properties and wear resistance of such coatings. TiN/GT35 exhibited the best load-carrying capacity and scratch/wear resistance. As a consequence, GT35 is the best substrate for TiN coatings of the substrate materials tested.     

高温氧气条件下CrNiMo钢的摩擦磨损特性研究

以CrNiMo钢和H96黄铜组成配副,利用QG-700型高温气氛摩擦磨损试验机,研究了高温氧气气氛环境中滑动速度、接触压力等对CrNiMo钢摩擦学特性的影响.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:在高温氧气气氛中,随着滑动速度和接触压力的增大,摩擦因数逐渐减小,磨损率逐渐增大.在滑动速度和接触压力逐渐增大的过程中,CrNiMo钢的主要磨损机制由粘着磨损转变为氧化磨损.     

Tribological behaviour of carbon and low alloy steels: effect of mechanical properties and test conditions

Abstract

In this paper, the effects of mechanical properties and test conditions on the tribological behaviour of ISO C45 carbon steel and ISO 42CrMo4 low alloy steel were studied. The tribological tests were carried out, without lubrication, on a reciprocating friction tester. Cylinder on flat contact configuration was adopted. The results showed that there is no obvious relationship between the mechanical properties and the friction ones. However, the variation in the coefficient of friction depends on the test conditions. In contrary to normal load, the effect of sliding speed on the coefficient of friction is not the same for the two steel nuances. The tribological properties are dependent, however, on the nature of wear debris.     

Wear behaviour of hydrogenated DLC in a pin-on-disc model test under lubrication with different diesel fuel types

The wear behaviour of hydrogenated diamond like-carbon (DLC) coating in DLC/steel tribological contact in a pin-on-disc model test under lubrication with two diesel fuels is presented in this work. The first diesel fuel was standard EN590 that contained ester-based antiwear additives. In contrast to EN590, the second diesel fuel, called GDK650, did not contain antiwear additives. It was experimentally observed that the antiwear additives are detrimental to the DLC. The effects of load, speed and temperature on the DLC and steel counterbody wear were investigated. Steel counterbody wear volume was found to be not affected by pressure, temperature, speed and lubricant, whereas the DLC-coating revealed correlation between the parameters and wear rate. Regarding the results of the tribological tests under both diesel lubrications, new mathematical wear laws were developed.     

The Effect of FeS Solid Lubricant on the Tribological Properties of Bearing Steel under Grease Lubrication

In order to improve the tribological properties of 52100 steel under grease lubrication, FeS solid lubricant was used in two ways. Low-temperature ion-sulfurization technology was utilized to prepare solid lubricant iron sulfide (FeS) films on the surface of 52100 steel, and FeS particles were mixed into the lithium grease as additive. The friction and wear properties were examined systematically on a “ball-on-disc” testing machine. The results showed that the tribological properties of bearing steel under grease lubrication can be improved either by using ion-sulfurization technique or by adding FeS microparticles into the grease. The tribological performance of sulfurized surface lubricated by grease is better than that of a plain surface lubricated by grease containing FeS microparticles at lower load and speed. The plain surface lubricated by the grease containing FeS micropaticles possesses better antiwear property under harsher conditions. The mechanism of the experimental results is discussed in detail.     

Tribological behaviour and wear mechanism of MoS2–Cr coatings sliding against various counterbody

MoS₂–Cr coatings with different Cr contents have been deposited on high speed steel substrates by closed field unbalanced magnetron (CFUBM) sputtering. The tribological properties of the coatings have been tested against different counterbodies under dry conditions using an oscillating friction and wear tester. The coating microstructures, mechanical properties and wear resistance vary according to the Cr metal-content. MoS₂ tribological properties are improved with a Cr metal dopant in the MoS₂ matrix. The optimum Cr content varies with different counterbodies. Showing especially good tribological properties were MoS₂–Cr8% coating sliding against either AISI 1045 steel or AA 6061 aluminum alloy, and MoS₂–Cr5% coating sliding against bronze. Enhanced tribological behavior included low wear depth on coating, low wear width on counterbody, low friction coefficients and long durability.     

Tribological Behaviors of Self-lubricating Coating Prepared by Electrospark Deposition

Cu/h-BN self-lubricating coating was prepared on AISI1045 steel by electrospark deposition. The friction coefficient and wear rates were measured using the ball-on-disk method, and the tribological behaviors were discussed. Results showed that the friction coefficient decreased with an increase in sliding speed and load. The wear rate decreased with an increase in sliding speed and increased with an increase in load. The self-lubricating coating exhibited much lower friction coefficient and wear rate than the uncoated mild steel under the test condition. SEM micrographs show that the main wear mechanisms of the self-lubricating coating are abrasive wear and fatigue wear.     

常用典型齿轮钢渗碳层的组织与性能

通过对3种齿轮钢20CrNi2Mo、17CrNiMo6、20CrMnMo进行渗碳及热处理,研究了不同渗碳时间后3种钢的表面碳含量及热处理前后的渗层硬度和组织。结果表明:3种钢的合金系数从高到低依次为20CrMnMo钢、17CrNiMo6钢、20CrNi2Mo钢,合金系数越大,相同渗碳条件下表面碳含量越高;高温回火前3种渗碳层的表面硬度均在45HRC以上,回火后均有所降低;高温回火前渗碳层的组织为马氏体、残余奥氏体等非平衡态混合组织。