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The aim of this study is to experimentally analyze the friction and wear responses of different steels to different surface films generated in oil-lubricated tribological contacts.

Tribological experiments were conducted using a 100Cr6 bearing ball sliding against a V155 carbon steel disk and 316L stainless steel disk, respectively. Lubricants with additives known to form zinc dialkyl-dithiophosphate (ZDDP) or Ca tribofilms were used.

Both of the ZDDP and Ca tribofilms helped stabilize the friction coefficient of the carbon steel and stainless steel. The ZDDP tribofilm could effectively protect the carbon steel from wear, in contrast to the stainless steel, whereas the wear of both carbon steel and stainless steel could be significantly reduced by the Ca tribofilm. In the case of neither ZDDP nor Ca tribofilms formation, the 100Cr6 ball was worn by the V155 disk and generated a special surface topography. A polishing wear mechanism was proposed to explain the wear of the 100Cr6 ball.

This study clearly shows the different friction and wear responses of steels to the different surface films and the response is dependent on the tested steel.

This study aims to clarify the influence mechanism of polishing solution type on the glazing evolution of fixed abrasive pad under different interfacial pressure conditions.

The tribological experiments were carried out on the friction and wear machinery with W3-5 diamond fixed abrasive pad and quartz glass workpiece under three polishing solution types of five pressure conditions. The changes of surface morphology, porosity and hardness of fixed abrasive pad were detected by white light interferometer, optical microscope and shore hardness tester.

The results showed that the glazed phenomenon of fixed abrasive pad is occurred after a certain time, which is more obvious with the increasing of interfacial pressures. The polishing solution type has a significant effect on the glazing time, although the glazed phenomenon is inevitable. The mechanism of it is that the micro-convex peaks on the surface of the fixed abrasive pad are easily wear, and the pores are blocked by the accumulation of waste debris generated during the experiment process. Thus, a smooth and high-density hard layer is formed on the surface of the fixed abrasive pad which induces the decreasing of the friction coefficient and surface roughness value. For selected polishing solution types, the wear rate of micro-convex peaks is different due to the corrosion action difference with polishing pad surface.

The main contribution of this work is to provide a new investigating method for further understanding the glazing evolution mechanism of fixed abrasive pad.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2023-0257/

The purpose of this paper is to use a wear test to determine the effect of sand on the wear rates of materials typically used in aerospace applications. Once a repeatable wear test has been established, it can be used to test any combination of materials or coatings. The effectiveness of several different test methods will also be evaluated, including the sample height, surface roughness and mass difference. In addition, the current work will observe the differences between applying sand before the samples are brought into contact or after. The wear rates obtained from these tests could also be used to predict the wear of other components in similar abrasive particulate environments.

A modified block-on-flat wear test of anodized aluminum on hard coat anodized aluminum was used to study this. The experiments were performed with and without sand to study the effects of the sand. Two methods of adding sand were also evaluated. Weighing and profilometry were used to study the differences between the tests.

Wear rates have been calculated based on both the change in the masses of the samples and the change in the height between the upper and lower samples over the course of each test. The wear rates from the change in the masses are repeatable with and without sand, but the results for the change in height show no repeatability without sand. In addition, only in the presence of sand do the trends for the two methods agree. The wear rate was found to be non-linear as a function of load and therefore not in agreement with Archard’s Wear Law. The wear rate also increased significantly when sand was present in the contact for the duration of the test. The sand appears to change the wear mechanism from an adhesive to an abrasive mechanism. Black wear particles formed both when there was sand and when there was not sand. The source of these particles has been investigated but not determined.

This work has not been previously published and is the original work of the authors.

This paper aims to study the tribological characteristics of the electrical contact system under different displacement amplitudes.

First, the risk frequency of real nuclear safety distributed control system (DCS) equipment is evaluated. Subsequently, a reciprocating friction test device which is characterized by a ball-on-flat configuration is established, and a series of current-carrying tribological tests are carried out at this risk frequency.

At risk frequency and larger displacement amplitude, the friction coefficient visibly rises. The reliability of the electrical contact system declines as amplitude increases. The wear morphology analysis shows that the wear rate increases significantly and the degree of interface wear intensifies at a larger amplitude. The wear area occupied by the third body layer increases sharply, and the appearance of plateaus on the surface leads to the increase of friction coefficient and contact resistance. EDS analysis suggests that oxygen elements progressively arise in the third layer as a result of increased air exposure brought on by larger displacement amplitude.

Results are significant for recognizing the tribological properties of electrical connectors in nuclear power control systems.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-03-2024-0098/

The purpose of this study is to develop understanding of the extended self-theory by focusing on the influence of other people in identity constructions as experienced in collectivist Eastern contexts. It specifically addresses the impact of being treated as an extended self on Arab-Muslim women’s identity constructions.

This study uses a qualitative research approach consisting of 23 in-depth semi-structured interviews. Nonprobability, purposive sampling is followed as the study targets Kuwaiti women who identify as former hijab/veil wearers. Sample diversity is attained in terms of Kuwaiti women’s demographical characteristics, including their age range, marital status and social class.

The findings of this study reveal paradoxes of experiencing the collective extended self through familial pressure to (un)veil and the strategies used by women to reject engaging with the collective extended self, including contextualizing, substituting and sexualizing the veil.

Existing studies related to the notion of the extended self are primarily conducted in Western contexts, and as such, are oriented toward personal accountability related to identity constructions. To complement this perspective and address the call for research on the extended self in collectivist societies, this study highlights the importance of recognizing the role of other people in influencing identity constructions in Eastern contexts.

This paper aims to research the tribological and dynamic characteristics of aeroengine hybrid ceramic bearings through wear experiments and simulation analysis.

First, the authors carried out wear experiments on Si₃N₄–GCr15 and GCr15–GCr15 friction pairs through the ball-disc wear test rig to explore the tribological properties of their materials. Second, using ANSYS/LS-DYNA simulation software, the dynamic simulation analysis of hybrid bearings was carried out under certain working conditions, and the dynamic contact stress of all-steel bearings of the same size was simulated and compared. Finally, the change of the maximum contact stress of the main bearing under the change of load and rotation speed was studied.

The results show that the Si₃N₄–GCr15 pair has better tribological performance. At the same time, under the conditions of high speed and heavy load, the simulation analysis shows that the contact stress between the ceramic ball and the raceway of the ring is smaller than the steel ball. That is, hybrid bearings have better transient mechanical properties than all-steel bearings. With the speed increasing to 12,000 r/min, the maximum stress point will shift in the inner and outer rings.

In this study, the tribological and transient mechanical properties of Si₃N₄ material were comprehensively analyzed through wear experiments and dynamic simulation analysis, which provided a reference for the design of hybrid bearings for next-generation aeroengines.

The purpose of this review is to comprehensively consider the material properties and processing of additive titanium alloy and provide a new perspective for the robotic grinding and polishing of additive titanium alloy blades to ensure the surface integrity and machining accuracy of the blades.

At present, robot grinding and polishing are mainstream processing methods in blade automatic processing. This review systematically summarizes the processing characteristics and processing methods of additive manufacturing (AM) titanium alloy blades. On the one hand, the unique manufacturing process and thermal effect of AM have created the unique processing characteristics of additive titanium alloy blades. On the other hand, the robot grinding and polishing process needs to incorporate the material removal model into the traditional processing flow according to the processing characteristics of the additive titanium alloy.

Robot belt grinding can solve the processing problem of additive titanium alloy blades. The complex surface of the blade generates a robot grinding trajectory through trajectory planning. The trajectory planning of the robot profoundly affects the machining accuracy and surface quality of the blade. Subsequent research is needed to solve the problems of high machining accuracy of blade profiles, complex surface material removal models and uneven distribution of blade machining allowance. In the process parameters of the robot, the grinding parameters, trajectory planning and error compensation affect the surface quality of the blade through the material removal method, grinding force and grinding temperature. The machining accuracy of the blade surface is affected by robot vibration and stiffness.

This review systematically summarizes the processing characteristics and processing methods of aviation titanium alloy blades manufactured by AM. Combined with the material properties of additive titanium alloy, it provides a new idea for robot grinding and polishing of aviation titanium alloy blades manufactured by AM.

Tantalum is a kind of metal material with moderate hardness, high ductility, small thermal expansion coefficient, excellent corrosion resistance and outstanding biocompatibility. The purpose of this study is that its tribological performance could be tested and analyzed so as to use it in different fields.

The friction resistance of a-Ta under dry friction conditions was tested at different roads. The relationships between load and friction coefficient, wear rate and two-dimensional shape of wear scars were studied.

The stable Ta₂O₅ film with lubrication effect was generated in the process of friction. And, the larger the test load, the more Ta₂O₅ would be generated.

This work lays a theoretical foundation for tantalum as an excellent wear-resistant material.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2023-0047/

FeNi36 (Invar-36) alloy is widely used in the fabrication of molding tools in aerospace industries but there remains a need to improve its wear and friction performance due to its relatively low hardness. The formation of a heat affected zone (HAZ) on the surface of Invar-36 cut by wire electric discharge machining (WEDM) is promising to enhance its tribological properties. This study aims to investigate the tribological performance of WEDM-treated Invar-36 via a ball-on-disk tribometer in dry-sliding conditions.

The untreated and WEDM-treated Invar-36 surfaces were reciprocated against an alumina ball at a sliding velocity of 40 mm/s, a stroke length of 10 mm and a sliding duration of 125 min under loads of 5, 10 and 20 N. The worn surfaces were characterized using a 2D profilometry and a scanning electron microscope equipped with energy-dispersive spectroscopy.

The results showed that the WEDM-treated surface had a superior friction coefficient and wear resistance in comparison to the untreated surface, due to the grown HAZ. There was found to be a 9.3%–11.4% decrease in the friction coefficient and a 47%–57% reduction in the wear volume after the WEDM treatment. Both the untreated and WEDM-treated Invar-36 surfaces found abrasion and plastic deformation as the dominant wear mechanisms.

Previous works have not focused on the tribological performance of the WEDM-treated Invar-36 extensively used for molding tools in aerospace industries. Our findings provide compelling evidence that the WEDM treatment improved the wear and friction performance of Invar-36 alloy because of the grown HAZ.

The purpose of this paper is to investigate the friction and wear mechanisms in lubricated sliding conditions of additively manufactured SS316L parts. The different viscous oils 5W30, 15W40, 20W50 and SAE140 are used. These investigations provide a theoretical basis for the high performance of printed and postheattreated SS316L.

Tribological tests were carried out on selective laser melting-made SS316L printed specimens and heat-treated specimens. The parameters in 15 min of test duration are 20 N of load, 200 rpm, 8 mm of pin diameter, 25 mm length, 80 mm of track diameter and EN31 counter disc body. This work presented the phenomena of lubrication regimes and their characterization, as identified by the Stribeck curve, and these regimes affect the tribological properties of additively manufactured SS316L under the influence of industrial viscous lubricants. The results are observed using Scanning electron microscope (SEM), X-ray diffraction (XRD) and wear tests.

The observations indicate that additively manufactured SS316L shows a reduced coefficient of friction (COF) and specific wear rate (SWR). This is credited to the utilization of different viscous lubricants.

This exclusive research demonstrates how various viscous lubricants affect the COF and SWR of printed and post-heat-treated SS316L parts. Lambda (λ), lubricant film thickness (h₀), surface roughness and wear mechanisms are studied and reported.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-04-2024-0110/