对凸轮轴进行了模拟试验，实现了新材料研发的快速筛选，出厂前成品的抽检等。大大提高了研发及生产效率，为发动机的性能提供了可靠的保证。

实现了新材料研发的快速筛选、出厂前的成品抽检以及众多供应商产品质量的统一，从根本上实现了体系化的质量管理，大大提高了产品合格率。

TE33发动机动力及其传动机构各部件摩擦试验机等设备对气门进行了不同工况的模拟实验，实现了新材料研发的快速筛选、不同工况的磨损研究，以及众多供应商质量的统一，大大提高了气门及发动机的使用寿命。

对产品进行模拟实验，实现了新材料研发的快速筛选，出厂前成品的抽检等。大大提高了研发及生产效率，为发动机的性能提供了可靠的保证。

Abstract The commercialattractivenessof rolls with greaterresistanceto wearandfatiguedamageis substantial.providing reducedrolling mil down times. increasedroll life. reducedproductsurfacedefectsand improvedstockgaugetolerances.Relatively little is known about1&' wearmechanismsof thesematerialswhich limit the usefullife of cold rolling mill work rolls.Two steelsof composition0.8%C/3%Craid 0.8%C/5%Cr. which are representativeof industry standardmaterials.havebeentestedin a rolling-sliding configuration (slippage.8C1t-againsta high speedsteel (M2) counterface.A comparisonhasbeenmadebetweensamplesmanufacturedby conventional processiDl (castingandforging) andby sprayforming. Sprayforming provideda microstructuresimilar to thatof the heavilyforged materialbutwitJt afiner averagecarbidesize (134 nm in thesprayformedand317nm in theforged,bothfor the3%Crsteels)andthesprayformedmaterill did not containthe occasionalcoarsecarbides( - 2 ~m) found in theforgedmaterial.The increasein Cr contentfrom 3% to 5%changed thecarbidefrom (Fe.Cr)3C (3%Cr steel) to (Fe.Cr)7C3(5%Crsteel) in bothsprayformedandforgedmaterials.However.boththe~ sizeandcarbidetype hadlittle effectonwearratewhentestedin thequenchedandtemperedcondition.Temperingof thequenchedsteelwa.s; undertakenin thetemperaturerange200-500 °c. which yieldedhardnessin the range540-890 H. for the 3% Cr steeland470-880 H. fIX" the 5% Cr steel. The wear coefficient decreasedsignificantly for an increase in hardnessfrom to 470 H.(k-l.72X 10-5mm3 N-1 m-l) ~ 750 H. (k-l.35X10-6 mm3N-1 m-l)but only fell slightly for hardnessvaluesabove750 H.. The friction coefficient was0.49-0.6.1': irrespectiveof loador materialtemper.Characterisationof worn surfacesindicatedthatsurfacestrainwaslimited to adepthof - 5-15 ~

new rubber firction tester machine appears to be a perverse property.

In rubbbery materials friction sometimes appears to be a perverse property

Abstract Considered as a plague for numerous industrial assemblies, fretting, associated to slight oscillatory displacement, is encountered in all quasi-static contacts subjected to vibration. Depending on sliding conditions, cracking or wear damage can be observed. During the past three decades there has been a huge development in surface treatments. Thousands of new surface treatments and coatings are now available. The critical challenge is to evaluate such treatments against fretting loadings. To achieve this objective, a fast fretting methodology has been developed. It consists in quantifying the palliative friction, cracking and wear responses through a very small number of fretting tests. By defining quantitative variables, a normalized polar fretting damage chart approach is introduced. Applied to shot peening, chromium coatings and WC-Co coatings, it demonstrates the potential benefit of a thermal sprayed WC-Co coating. © 2005 Elsevier B.V. All rights reserved.

Abstract Laboratory tests to evaluate piston ring and cylinder liner materials for their friction and wear behavior in realistic engine oils are describe to support the development of new standard test methods. A ring segment was tested against a flat specimen of gray cast iron typical o cylinder liners. A wide range of lubricants including Jet A aviation fuel, mineral oil, and a new and engine-aged, fully formulated 15W4 heavy duty oil were used to evaluate the sensitivity of the tests to lubricant condition. Test temperatures ranged from 25 to 100 8C. A steppe load procedure was used to evaluate friction behavior using a run-in ring segment. At 100 8C, all lubricants showed boundary lubricatio behavior, however, differences among the lubricants could be detected. Wear tests were carried out at 240 N for 6 h at 100 8C with new rin segments. The extent of wear was measured by weight loss, wear volume and wear depth using a geometric model that takes into accoun compound curvatures before and after testing. Wear volume by weight loss compared well with profilometry. Laboratory test results ar compared to engine wear rates.

Molybdenum nitride coatings were deposited onto high-speed steel (HSS) substrates by the arcPVD technique. It was possible to producecoatings with MO%N and MoN structure by varying the nitrogen partial pressure between 0.4 and 1.5 Pa. The relationships between hardness, thickness, and crystallographic structure of the coating and the deposition parameten were investigated. Hardness of the coatings increased with the increase of nitrogen content of the coating. Tribological behavior of the coatings was detennined by ball-on-disk wear tests. The wear behavi~ of Mo-N~oated HSS samples against alumina balls was better than that of TIN-coated ~Electrochemical polarization experiments were conducted in 1 N sulfuric acid. The porosity of the samples was detemtined by the copper decoration test The coating with the lowest nitrogen content showed the best com)Sjon protective properties in the electrochemical tests. C 1997 Elsevier Science SA.

The design and development ofa power circulating rollinl Contact disc machine is descn"bed. Each disc is medlaDially coupled to a Iepamely excited d.c. electtical machine whose armatures are CODDected electtially.When the discs develop ttaaiOD. power circulates by one machine acting as a motor and the other as a generator.In this way conuoUed ttactioo with a ltepleas variation of sliding speed can be m.inftifted between the rolling discs.

A linear model of lubricant-related engine friction was developed.Based on lubrication {undamentcils, the technique is comprised of three simple bench tests that respectiuel_v operate under thick fluid-film hy~ynamic lubrication, elastoh)drodynamic lubrication,and boundary lubrication. With adequate configuration and appropriate test conditions, these bench tests are seen to simulate major friction losses in a typical internal combustion engine.

A new test for assessing the friction and wear properties of materials and lubricants is presented. Two elongated test specimens, preferably bars or rods, are used. The orientation of the test specimens and their relative motion (sliding or rolling or a combination of both) during testing is arranged in such a way that the contact spot moves along a contact path on each specimen, and each spot along this path on one specimen will only make contact to one spot on the other specimen, and vice verse, see Fig. 1. By contact spot is here meant the area overwhich the contact load is distributed.

Numerous methods have been used to assess the mechanical durability of paints and other types of surface coating

In rubbery materials friction sometimes appears to be a perverse property.

Abstract Considered as a plague for numerous industrial assemblies, fretting, associated to slight oscillatory displacement, is encountered in all quasi-static contacts subjected to vibration. Depending on sliding conditions, cracking or wear damage can be observed. During the past three decades there has been a huge development in surface treatments. Thousands of new surface treatments and coatings are now available. The critical challenge is to evaluate such treatments against fretting loadings. To achieve this objective, a fast fretting methodology has been developed. It consists in quantifying the palliative friction, cracking and wear responses through a very small number of fretting tests. By defining quantitative variables, a normalized polar fretting damage chart approach is introduced. Applied to shot peening, chromium coatings and WC-Co coatings, it demonstrates the potential benefit of a thermal sprayed WC-Co coating.© 2005 Elsevier B.V. All rights reserved. Keywords: Fretting; Fatigue; Cr; WC-Co; Friction; Cracking; Wea

A novel 12-station hip joint simulator with an anatomic position of the prosthesis was designed and built.

Abstract A robber wheel abrasion tester with some advantages over the design described in ASTM 065 has been designed and characterised. In the new design the specimen was held horizontally. It was therefore possible to determine the actual mass flow rate of abrasive abrading the specimen and consequently the number of particles in the contact zone and the load carried by each particle. The abrasive feed system was designed to improve control over the conditions in the contact region. The performance of the apparatus was evaluated in tests on low carbon(AiSI 1020) steel, with wheels made from cast polyurethane and chlorobutyl rubber. The influences of load, sliding speed and robber hardness were investigated. Temperature rises of wheel, specimen and sand, and the friction force were measured; the main mechanism of heat dissipation was through the continual flow of fresh abrasive past the specimen.

Introduction The Tribology Group in the Department of Materials Technology (formerly the Metallurgy Department) at Brunei University has been active since the late I960s. Most of the early work was on dry wear of both steels and cast irons. It was a logical development when work commenced in the middle 1970s on lubricated wear of materials. particularly those used in the internal combustion engine. This work was supported by SERC and Esso Petroleum Ltd and later Esso Chemical Ltd. During this period. two students obtained PhDs and another has recently submitted a thesis for examination. all concerned with lubricated wear of steel and cast iron engine components. It became quite clear towards the middle 1970s that other materials in both bulk form and as surface coatings would become important as the drive for lighter weight and improved fuel efficiency gathered speed.

The wear characteristics of a nickel-base alloj has hem cOmpare with a cobalt-base alloy. Both have hem investigated under abrasive and also adhesive wear conditiofU. Under abrasive conditions, the cobalt alloy wears at about half the rate of the nickel ailqy rom though they are approximately the same hardness. Under adhesive conditions, sliding against a hardened steel ring, wear of the nickel alloy is vastly superior to the cobalt alloy. The metallography of wear and the characteristics of the worn surfaces and wear debris COTTelate very well. Under abrasive conditions, wear occurs by de- lamination to produce platelike metallic debris. Under adhesive conditimu, the nickel alloy produces a protective oxide film with no evidence of adhesion. The cobalt alloy adheres to the steel disk with transfer from one surface to the other and with the production of lumps of metallic debris.

Summary Pin-on-discexperiments were carried out to produce both oxidative and metallic wear. Measurementof the temperature rise of the aluminium wear pins and calculations basedon these results show that the temperatures are too low to account for the oxide produced during wear. Oxidation during wear occurs by a two-stage processof oxidation of asperitiesfollowed by fracture and compaction into the valleys on tlle metal surface.As the oxide layer increasesin thickness it also becomessmoother and the wear rate remains relatively low.

With the increased pressure being put on matericals used in wear application,it is important to correctly diagnose the reason for excessive wear,and then to improve the design so that the life of engineering systems is extended.As the range of materials and processes used by engineets,more ,rather than less,wear problems are likely to be encounteed,in the next decade,experiment working in the wear field must apply the wide range of techniques currently available to put our knowledge on a more quantitative basis.

Wear is discussed in terms of its damaging affect on changes of topography of the surface. volume of material removed, transitions in behaviour, and the effect of wear debris on performance of engineering systems. Friction and wear are characteristics of the engineering system and improvements may be obtained by changing operating parameters and condition of the wear surface, or by. optimizing the wear counterface combinations. Wear mechanisms are described, largely from the observations obtained from the use of scanning electron microscopy and, of these, wear under abrasive and metal-to-metal sliding conditions is most often encountered in industrial machinery. The study of wear is now becoming both more widespread and more fundamental and considerable efforts are being made to develop improved surfaces. Surface coatings, surface treatments, and the use of powder metallurgy are becoming more widespread to combat the extremely difficult conditions encountered at tribological surfaces. PM/O177exploration, production, and process plants than any other components.

Wear of piston rings and cylinder liners has been examined tLSing a wide rang of techniques and a very good cOTT~lation has been obtained through the use of these, with the w~ar behavior in servic engines, test-bed tngines, and laboratory tests. This should form the basis for further eelopment of mattriaLr, particularly surface coatings, to inCT~as~ both the ~fficienC)' and w~ar lif~ of the componnIts. A clear pictur~ of the wear mechanisms including abrasion,scuffing, and corrosion has emerg~d, but much remains to be done,particularly in inttTT~lating wear and lubrication to produce smooth, etched, long-lif~ surfaces. A wear debris atlas is available which, however, is somewhat limited in its tLSe and information should be collected to establish a "wear atlas," particularly for will establish~d contacting bodies and for specific engin ering applications. Much of this information is already available for piston rings and rylindtr liners, some of which is presented in this investigation.

AkJminum allays containing silicon, copper, iron and nickel have been rubbed against steels of different hardness and al~ a grey cast iron. In all cases both oxidative and metallic wear occurs. The transition load between oxidative and metallic wear is increased as the silicon content increases and the addition of copper al~ brings about significant increases. The presence of copper is beneficial irrespective of its effect on the mechanical properties produced by solution treatment and ageing. In oxidative wear. transfer of iron from the counterface to the aluminum alloy occurs and a very complex surface containing AIFe and a AI203 is produced. Wear in the oxKfative regime occurs by fractUre and spalling of the oxide from the aluminum allay surfure. Metallic wear occurs by plastic defor-ation, fractUre and metal transfer of aluminum to the surface of the steel counterface.Wear behavior of these alloys is not related in any way to their bulk mechanical propenies or microstructure. Considerable further effon is required before our knONledge of surfaceproperties is sufficient to design improved we.resistant alloys for engine components.

Summary The pattern of roughness and wear has been obtained by varying the speed, the number of passes and the pre-roughness of the samples in both dry and lubricated sliding conditions. Three-dimensional graphs of wear HTSUS speed versus sliding time and roughness of the worn surfaces were produced and a linear relation between the variation of the roughness and the amount of wear at a high number of passes has been determined.The Initial dry wear rate is influenced by the prior surface roughness. In the case of lubricated conditions the influence of prior roughness is not pronounced.In dry sliding the smooth surfaces in the running-in stage roughen and the rough surfaces become smoother, while in lubricated conditions both sur- faces become smoother in the first few passes. Sliding perpendicular to the lay produces rougher surfaces and more wear than is the case in the parallel direction.

Wear resistance is not an instrinsic property a metal in the same way as is young'smodulus or thermal conductivity although these and other properties may have an appreciable effect on wear resistance

Boronising is a time/temperature dependent diffusion tre.tment similar to carburising and nitriding which can be carried out in liquid;solid or gaseous media. Using a pack medium. the authors have established time/temperature parameters to produce different coating thicknesses on steels with. range of carbon contents and h.ve determined friction .nd wear char.cteristics of treated Samples under dry conditions. Boronising inhibits adhesive wear during running-in and suppresses the transition from mild to severear. Abrasive we.r resistnce is also improved. compared with on-boronised and carburised steel. and depends upon both substrate materia.and coating thickness.

Summary An attempt is made to indicate how the results from simple unlubricated pin-on-disc type wear tests can be meaningfully interpreted by a designer in his approach to the selection of materials for practical applications.

Wear in low speed diesel cylinder liners can vary over wide limits: generally up to 0.15 mm per thousand hours of operation on diameter is considered acceptable. In some cases wear of 2 or 3 mm per thousand hours may occur and would be considered most unsatisfactory .