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The purpose of this paper is to present the results of research into using an additive to SAE 15W/40 engine oil during operation and its influence on lubricating properties (normalised tests) on weld point Pz, non-seizure load Pn, load wear index Ih and on seizure load Pt. The friction pair consisted of a group of four balls and the tested lubricant. Moreover, the author tested the influence of an additive to engine oil (non-normalised tests) on tribological properties, including friction force, wear and the temperature of friction area for the C45 steel/210Cr12 steel friction joint. She also determined the influence of an additive to engine oil on the formation of the operating surface layer. The research results helped to build the model of the boundary layer that was formed as a result of adding an additive to engine oil.

The lubricant properties of engine oil and engine oil to which an additive was added during operation were determined according to PN-76/C-04147. The following are the indexes of lubricant properties: weld point Pz, load wear index Ih, non-seizure load Pn, seizure load and average scar diameter. The Pz, Pn and Ih indexes were determined at abruptly increasing load to the moment of welding of the friction pair. The Pt index was determined at the increasing load of the friction pair from 0 to 800 daN at the speed of 408.8 N/s. The tests of tribological properties (friction force, wear and the temperature of friction area) were conducted for the C45/210 Cr12 friction pair in the presence of a lubricant and a lubricant with an additive.

The modification of SAE 15W/40 engine oil with the additive added during operation resulted in improved indexes of lubricant properties Pz, Pn, Ih and Pt and average scar diameter. The boundary layer for the modified oil breaks after a longer time and at lesser friction force. The modification of the engine oil reduced the wear of the friction pair. After the friction process, element composition in the surface layer of the wear trace and its distribution were determined in relation to applied lubricants. A significant amount of sulphur, phosphorus and oxygen, as well as an insignificant amount of copper, was observed in the wear trace after the friction process in the presence of the lubricant medium. The distribution of elements in the wear trace when the engine oil with the additive was used is steady in the wear trace and outside it. Some sulphur, phosphorus and chlorine were found in the wear trace.

The results of tests on tribological properties (non-normalised tests) confirmed the positive affect of the additive to engine oil on lubricant properties (normalised tests). The modification of the engine oil caused reduced friction force and the reduced wear of the friction pair. The reduction of friction force and wear was the result of the formation of the surface of a greater amplitude density of unevenness tops in the friction process. Moreover, the operating surface layer, created in the friction process when the additive was added to the engine oil, had greater load participation at 50 per cent C. This operational surface layer improved tribological properties, i.e. it reduced value of friction force and wear. The test results were used to build a model of the boundary layer created as a result of the additive added to engine oil.

The purpose of this paper is to develop novel ashless additives and to meet the need for formulating ashless anti‐wear (AW) hydraulic fluid or other industrial lubricating oils. This paper also aims to investigate the tribological behaviours and mechanism of an acrylate of dialkyl dithiophosphoric acid (ADDP), as an additive in some group I/II base oils compared with some traditional s‐p containing AW additives.

ADDP is synthesized in the laboratory. The chemical composition and structure of the lubricating additive are analyzed by means of infrared spectroscopy. Its extreme pressure (EP), AW and friction reduction properties as additive in base oils, compared with some traditional s‐p containing AW additives, are investigated using a four‐ball machine according to relative testing standards. The tribological mechanism is discussed according to the scanning electron microscope (SEM) analytical data.

The results indicate that the four‐ball PB value of the prepared ADDP in HVIWH650 is better than that of the IRGLUBE 353; the thermal stability of ADDP is equivalent to the zinc dialkyl dithiophosphate (ZDDP) and the SEM data show that the prepared ADDP additive could form a layer of uniform film on the worn surface serving as lubricant and protective film. This may be the chief reason why the prepared ADDP possesses better AW property than ZDDP.

However, more experimental studies such as the synergic effect with other additives should be performed, from which it could be learned whether the novel AW additive would be applicable in industrial oils.

The results may be useful for the researchers to formulate some ashless industrial oils.

A novel additive was synthesized in the laboratory; it would find a promising industrial application as an ashless AW additive.

In this study, an attempt is made to show the linkage between the oil additive and journal bearing the running conditions such as temperature, load, speed, etc. in effecting lubricating. It is well known that öne of the roles of additives is to form protective layer to reduce friction coeffıcient in lubricated contacts.

The tests were performed at three different loads, and eight speeds. The tests were carried out for three different commercial additives that are concentration ratio of 3 per cent.

The test results of the experimental coeffıcient of friction were graphically presented. The highest reduction in the friction coeffıcient was obtained at high temperature (100°C) in the tests than room temperature (25°C) tests.

In this study, effects of commercial oil additives on the friction coefficîent in the journal bearing under statically loaded have been studied experimentally at 25 and 100°C temperatures.

Lubricating oils find applications in engines, industrial uses, greases and automotive transmissions. The majör uses of these oils are in engines (55 per cent), industry (27 per cent), processes (9 per cent), greases (5 per cent) and automotive transmissions (4 per cent). Lubricants perform a variety of functions in automotive application. One of the important functions is to reduce friction and wear in movîng machinery.

Generally, by adding additives to engine oil the lower friction coeffıcient were observed comparison engine oil both at 25 and 100°C temperatures. But, the smallest friction coefficient was obtained in the tests at 100°C comparison with the tests at 25°C in the additive addition to engine oil tests.

The purpose of this paper is to study tribological properties of two novel additives in the diester and provide adequate information on the relationship between the diester and the additives.

The two 2‐mercaptobenzothiazole derivatives, referred to as BZIA, BZOA, are synthesized with one pot; their tribological performances are evaluated using a four‐ball friction and wear tester, and the worn surface was analysed with scanning electron microscope and X‐ray photoelectron spectroscopy (XPS).

The two compounds as the additives in the diester possess excellent load‐carrying capacities, rather good anti‐wear (AW) and friction reduction properties. According to the XPS results, both the additives reacted with counter‐face metal and generated a sulphur‐containing inorganic film and a complex adsorption film. The inorganic film obtained with the additive BZOA consisted of FeS₂, FeSO₄ and Fe₂(SO₄)₃, whereas the inorganic film obtained with the additive BZIA consisted of FeS₂ or FeS. The adsorption layer for the two additives contained N‐containing compounds.

The interaction of the two additives with the diester needs to be further explored.

Two useful, environmentally friendly, AW lubricating oil additives are synthesized with one pot.

The paper provides a study of some N, S‐containing heterocyclic compounds as environmentally friendly lubricating oil additives.

This study aims to examine factors that determine the adoption of additive manufacturing by small- and medium-sized industries. It provides insights with regard to benefits, challenges and business factors that influence small- and medium-sized industries when adopting this technology. The study also aims to expand the domain of additive manufacturing by including a broader range of challenges and benefits of additive manufacturing in literature.

Using data collected from 175 small- and medium-sized industries, the study has examined through Mann–Whitney test to understand the difference between owners and design engineers on additive manufacturing technology adoption in small- and medium-sized companies.

This study suggests contribution to academic discussion by providing associated factors that have significant impact on the adoption of additive manufacturing technology. Related advantages of additive manufacturing are reduction in inventory cost, lowering the wastage in production and customization of products. The study also indicates that factors such as cost of machinery, higher level of cost in integrating metal components have a negative impact on the adoption of this technology in small- and medium-sized industries.

Because of the chosen research approach, the research results may lack generalizability. Therefore, researchers are encouraged to test the proposed propositions further in the field of challenges and growth in other areas of application of additive manufacturing, for instance, medical sciences, fabric and aerospace.

The study provides important implications that are of interest for both research and practitioners, related to technology management in small- and medium-sized industries, e.g. foundry and machining industries.

This work/study fulfills an identified need of the small- and medium-sized companies in adopting new technologies and contribute to their growth by understanding the need to accept and implement technology.

This paper fulfills an identified need to study how small- and medium-scale companies accept new technologies and factors associated with implementation in the manufacturing process of the organization.

Understanding consumers’ food safety practices are helpful in reducing foodborne illnesses. The purpose of this study is to evaluate the influence of education on knowledge, attitude and practices toward food additives.

This interventional study was performed by random sampling of 826 employees in Isfahan University of Medical Sciences from January 2018 to March 2019. The knowledge, attitude and practices of the employees toward food additives were assessed by a self-administered and structured questionnaire. Two-month education was conducted visually by using pamphlets, posters and leaflets. Descriptive statistics and paired t-test were done by SPSS24 at significant levels of p < 0.05.

The results showed that the respondents were very concerned about preservatives, colorants, and artificial sweeteners in foods. Before the education, the percentages collected for the knowledge, attitude and practice were 79.0, 48.9 and 46.7, respectively. Overall, knowledge scores were improved from 79.0 to 88.9 per cent when the education was offered. Safety attitude scores significantly increased, with a 50 per cent difference between the pre and post values. A significant difference was observed in the percentage of knowledge, attitude and practice of the employers before and after education (p < 0.05). Almost half of the respondents chose leaflets and pamphlets as a preferable tool for learning.

Education may be needed for improving knowledge and attitude about food additives. It also helped the respondents to select healthier food. This study suggests more communication programs regarding food safety issues.

This paper aims to propose a new scuffing model caused by the depletion of additives in boundary lubrication condition.

The differential equation governing the distribution of additive content in the fluid film was used. This formula was derived from the principle of mass conservation of additives considering the consumption due to surface adsorption of wear particles. The occurrence of scuffing was determined by comparing the wear rate of the oxide layer with the oxidation rate.

If the additive becomes depleted while sliding, the scuffing failure occurs even at a low-temperature condition below the critical temperature. The critical sliding distance at which scuffing failure occurred was suggested. The experimental data of the existing literature and the theoretical prediction using the proposed model are shown to be in good agreement.

It is expected to be used in the design of oil supply grooves for sliding bearings operating under extreme conditions or in selecting the minimum initial additive concentration required to avoid scuffing failure under given contact conditions.

Additive manufacturing (AM) methods such as material extrusion (ME) are becoming widely used by engineers, designers and hobbyists alike for a wide variety of applications. Successfully manufacturing objects using ME three-dimensional printers can often require numerous iterations to attain predictable performance because the exact mechanical behavior of parts fabricated via additive processes are difficult to predict. One of that factors that contributes to this difficulty is the wide variety of ME feed stock materials currently available in the marketplace. These build materials are often sold based on their base polymer material such as acrylonitrile butadiene styrene or polylactic acid (PLA), but are produced by numerous different commercial suppliers in a wide variety of colors using typically undisclosed additive feed stocks and base polymer formulations. This paper aims to present the results from an experimental study concerned with quantifying how these sources of polymer variability can affect the mechanical behavior of three-dimensional printed objects. Specifically, the set of experiments conducted in this study focused on following: several different colors of PLA filament from a single commercial supplier to explore the effect of color additives and three filaments of the same color but produced by three different suppliers to account for potential variations in polymer formulation.

A set of five common mechanical and material characterization tests were performed on 11 commercially available PLA filaments in an effort to gain insight into the variations in mechanical response that stem from variances in filament manufacturer, feed stock polymer, additives and processing. Three black PLA filaments were purchased from three different commercial suppliers to consider the variations introduced by use of different feed stock polymers and filament processing by different manufacturers. An additional eight PLA filaments in varying colors were purchased from one of the three suppliers to focus on how color additives lead to property variations. Some tests were performed on unprocessed filament samples, while others were performed on objects three-dimensional printed from the various filaments. This study looked specifically at four mechanical properties (Young’s modulus, storage modulus, yield strength and toughness) as a function of numerous material properties (e.g. additive loading, molecular weight, molecular weight dispersity, enthalpy of melting and crystallinity).

For the 11 filaments tested the following mean values and standard deviations were observed for the material properties considered: p_a = 1.3 ± 0.9% (percent additives), M_w = 98.6 ± 16.4 kDa (molecular weight), Ð = 1.33 ± 0.1 (molecular weight dispersity), H_m = 37.4 ± 7.2 J/g (enthalpy of melting) and = 19.6 ± 2.1% (crystallinity). The corresponding mean values and standard deviations for the resulting mechanical behaviors were: E = 2,790 ± 145 MPa (Young’s modulus), E’ = 1,050 ± 125 MPa (storage modulus), S_y = 49.6 ± 4.93 MPa (yield strength) and U_t = 1.87 ± 0.354 MJ/m^³ (toughness). These variations were observed in filaments that were all manufactured from the same base polymer (e.g. PLA) and are only different in terms of the additives used by the manufacturers to produce different colors or different three-dimensional printing performance. Unfortunately, while the observed variations were significant, no definitive strong correlations were found between these observed variations in the mechanical behavior of the filaments studied and the considered material properties.

These variations in mechanical behavior and material properties could not be ascribed to any specific factor, but rather show that the mechanical of three-dimensional printed parts are potentially affected by variations in base polymer properties, additive usage and filament processing choices in complex ways that can be difficult to predict.

These results emphasize the need to take processing and thereby even filament color, into account when using ME printers, they emphasize the need for designers to use AM with caution when the mechanical behavior of a printed part is critical and they highlight the need for continued research in this important area. While all filaments used were marked as PLA, the feedstock materials, additives and processing conditions created significant differences in the mechanical behavior of the printed objects evaluated, but these differences could not be accurately and reliably predicted as function of the observed material properties that were the focus of this study.

The testing methods used in the study can be used by engineers and creators alike to better analyze the material properties of their filament printed objects, to increase success in print and mechanical design. Furthermore, the results clearly show that as AM continues to evolve and grow as a manufacturing method, standardization of feedstock processing conditions and additives would enable more reliable and repeatable printed objects and would better assist designers in effectively implementing AM methods.

The purpose of this study is to reduce the use of Zinc dialkyl dithiophosphates (ZDDP) and improve the frictional properties and thermal oxidation stability of Perfluoropolyether (PFPE) grease by adding antioxidant additives. The addition of antioxidants can reduce the consumption of ZDDP as an antioxidant, thus improving the anti-wear efficiency of ZDDP and reducing the excess phosphorus element in the grease.

In this study, an antioxidant with good comprehensive performance was selected from several antioxidants by tribological tests and high-temperature tests. Then, the effect of its combination additive with ZDDP on PFPE grease was investigated. The anti-wear property, anti-friction property, thermal oxidation stability and extreme pressure property of greases containing different proportions of ZDDP and antioxidant were tested by four-ball tester and synchronous thermal analyzer (STA). The effects of additives on properties of grease were analyzed by SEM, EDS, LSCM, XPS and FT-IR.

The research shows that 2,6-Di-tert-butyl-4-methylphenol (BHT) can be used as an antioxidant in combined additives to reduce the antioxidant reactions of ZDDP, thus improving the anti-wear efficiency of ZDDP and further enhancing the anti-wear performance of the grease. Moreover, BHT and ZDDP have a synergistic effect on the high temperature performance of the PFPE grease due to their different antioxidant mechanisms.

In this paper, the problems related to PFPE grease are studied, which has a certain guiding effect on the industrial application of fluorine grease and the related formulation design.

In this paper, the properties of PFPE grease under different lubricating condition were studied. The synergistic lubrication effect of antioxidant and ZDDP are discussed. It provides experimental and theoretical support for reducing the content of ZDDP and improving the performance of additives.

The purpose of this paper is to present the tribological, anticorrosion and antirust properties of three 2,5-dimercapto-1,3,4-thiadiazole (DMTD) derivatives as water-soluble additives in water–glycol hydraulic fluid.

DMTD derivatives possessing excellent corrosion inhibiting and extreme-pressure (EP) properties have long been used as metal passivators and load-carrying additives in lubricating oils and grease. However, there are seldom literatures about DMTD derivatives as water-soluble lubricant additives as yet. In this work, three DMTD derivatives were synthesized and investigated as water-soluble additives in the water–glycol hydraulic fluid. Their tribological properties were evaluated in detail by four-ball wear test machine and Optimol SRV-IV oscillating friction and wear tester. Meanwhile, their anticorrosion and antirust properties were also investigated by copper strip corrosive tests and antirust tests, respectively. The worn surfaces were analyzed by scanning electron microscope and X-ray photonelectron spectroscope, and the EP, antiwear and friction-reducing mechanisms were primarily proposed.

The synthesized three DMTD derivatives (coded as A, B and C) have excellent solubility in the base liquid of the water–glycol hydraulic fluid. The experimental results demonstrated that all these compounds, especially A, could remarkably improve the EP, antiwear and friction-reducing properties of the base liquid. Furthermore, they all have perfect copper corrosion inhibiting and antirust properties with low adding concentration (< 3 weight per cent) in the base liquid and hence could be used as multifunctional additives in the water–glycol hydraulic fluid.

This research only focused on the synthesized DMTD derivatives. If possible, some other thiadiazole derivatives also should be investigated.

The synthesized DMTD derivatives, especially compound A, can be used as multifunctional water-soluble additives in the water–glycol hydraulic fluid.

In this paper, three DMTD derivatives were synthesized and their tribological behaviors as water-soluble lubricant additives were investigated for the first time. In addition, the EP, antiwear and friction-reducing mechanisms were also put forward.