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This study aims to examine the effect of the antiwear resistance of plain zinc-dialkyldithiophosphate (ZDDP) oil in the presence of Titanium-fluoride/iron-fluoride/polytetrafluoroethylene (TiF₃/FeF₃/PTFE) in the time to tribofilm breakdown and extent of wear under extreme boundary lubrication using a contact load of 317 Newton and a rotational speed of 700 rpm to simulate the cold start of a car engine. The mechanism of tribofilm formation and breakdown was followed carefully by monitoring the friction coefficient for different surface roughnesses over the duration of several reproducible tests that were performed in a ball on cylinder tribometer.

The heating time of the cylinder dipped in the specified lubricant blend then set for one minute before testing and the break in period of 2 minutes to cool the contacting metal to metal surfaces during tribological testing played important roles in minimizing friction and wear, and are directly proportional to the durability and time for breakdown of the tribofilm. This article addresses the improvement of water drop contact angles for different surfaces during heat treatment and the tribological enhancement of antiwear additives when optimum concentration of fluorinated catalysts and PTFE is used in connection with reduced surface roughness and break in period.

Design of Experiment software, scanning electron microscopy, energy dispersive spectroscopy and nanoindentation were used in this study to evaluate the antiwear resistance films when using 0.05 per cent phosphorus ZDDP plain oil with 0.5 weight per cent TiF3 + 0.5 weight per cent FeF3 + 2 weight per cent PTFE and when applying 2 minutes break in time to cool down the contacting bodies when temperature rises. Results indicated that the coated film on the thermally treated surfaces that is reflected as white patches on the SEM images is a function of the antiwear additives contribution; it is also shown to have positive influence on the friction and wear performances during tribological testing.

This research involved the study of lubricant and surface interactions with antiwear additives under boundary lubrication and extreme pressure loading. Several researchers studied these effects and submitted articles to the journal. This is the first time that a break in period was used with surface conditions to simulate car stops in heavy traffic conditions.

The purpose of variable loading conditions (392 N-785N-392N-785N) with break-in period were used to study interactions between zinc dialkyl dithiophosphate (ZDDP) 0.1 P% (phosphorus) and fine-grade molybdenum disulfide (MoS₂) 3%, in different mixtures of NLGI 2 lithium stearate grease. Four-ball wear tests were used to evaluate the tribological properties of different grease mixtures such as coefficient of friction and wear. ASTM 2266 as reported by earlier studies is useful, but it is not representative of real-life applications where variable loads and speeds and different break-in periods play a role and could change the results and the nature of tribofilms.

In this study, chemical and mechanical properties of tribofilms were examined. Moreover, design of experiment was used to examine the data and shorten experimentation time. Research described here is investigating variable loading conditions for real-life applications by using a break-in period of 2 min at the start to minimize asperities and establish a clean surface. Design expert (DOE) analyzes responses to reveal those variables that are single factor and those that are multifactor whether synergistically or antagonistically.

The results indicated that spectrum loading with break-in period showed reduction in wear when tested in greases with ZDDP/MoS₂ combinations. Ramping up or down the load every 7.5 min for a rotational speed of 1,200 rpm and a total of 36,000 revolutions or 30-min time slowed the wear properties of lithium-based grease under different MoS₂ and ZDDP concentrations. Experiments indicated that wear was largely dependent on the loading condition and ZDDP additives during specific break-in period at 1,200 rotational speed. It is believed that MoS₂ greases perform better under spectrum loading and under constant loading when mixed with ZDDP phosphorus.

This research indicates that there is a synergistic interaction between ZDDP, MoS₂ and variable loading especially when a break-in period is applied. The results indicated that wear was largely dependent on the specific speed used with spectrum loading as presented in the energy dispersive spectroscopy and the Auger electron spectroscopy analysis, and thus a 3% MoS₂ grease with ZDDP (phosphorus: 0.1 Wt.%) are needed to improve the wear resistance and improve the friction characteristics.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2024-0016/

The purpose of this paper is to formulate heavy-duty lithium complex grease using low molecular weight poly tetra fluoro ethylene (PTFE) micro-particles as extreme pressure (EP) additive manufactured by E-beam scissoring and ultra-high speed grinding process of pre-sintered PTFE scrap.

Lithium complex grease is formulated with PTFE micro-particles, and optimum treat rate was studied by standard bench tests by ASTM D 2266 and IP-239 for tribological properties and compared with commercially available Molybdenum Di sulphide (Moly)-based lithium complex grease. The performance of the grease was further evaluated by a cyclic load test at varying speeds and loads to simulate the operational field conditions.

The lithium complex PTFE grease was manufactured using PTFE micro-particles as EP additive. The PTFE micro-particles dispersed in the lithium complex grease significantly improve the anti-wear performance and load bearing properties. Further, when the product was tested under a cyclic load conditions on standard tribological bench test against commercially available Moly lithium complex grease, shows stable anti-wear properties and reduced coefficient of friction.

The low molecular weight PTFE micro-particles, manufactured in the in-house electron beam (E-beam) and ultra-high speed micronizer facility from a pre-sintered PTFE scrap has been used as EP additive for grease applications for the first time. The results on the cyclic load tests indicate significant performance improvement in retaining the anti-wear and friction properties. Thus, value addition is done in formulating superior performance grease and evaluating under cyclic load conditions similar to field operating conditions and also in creating value added additives by converting the pre-sintered PTFE scarp which is environmental hazard due to poor biodegradability, creating a cyclic economy and a sustainable concept.

The aim of this paper is to explore the relationship between terrorist activities in Pakistan and the stock market development.

Using Terrorism Impact Factor (TIF), a unique score developed for this paper, an insight is provided into the causal relationship that exists between terrorism and Karachi Stock Exchange (KSE) index. Quantitative significance of the impact of terrorist activities on stock index is also discussed in the paper.

Through the empirics of the study, it is analyzed that terrorism negatively impacts stock market returns in the long run; whereas no significant relationship between stock market returns and terrorism is estimated in the short run.

A potential limitation of the study was the constraint related to the available yearly economic growth and other economic variables' data. The TIF created for the study was based on the terrorist activities from 2001 to mid‐2011 on an incident‐to‐incident basis. A yearly measure would have provided 11 data points for the study, which are considered insufficient for econometric analysis.

It is recommended that governments pay particular attention to economic recovery in the aftermath of terrorist attacks. Policies aimed at combating terrorism must be the priority of the government, so that its harm can be reduced, if not exterminated.

Terrorism, with its all kinds of impacts, affects the society and its activities and therefore must be eliminated if an economy needs to prosper.

This study envisions the overall impact of terrorist activities, not just a single activity, on the health of the economy. For studying this impact, a Terrorism Impact Factor (TIF) scale has been developed for this study, based on the impact of each terrorist activity in the country.