Copyright © 2021 O.O. Mikosianchyk, О.Ye. Yakobchuk, R. H. Mnatsakanov, A.M. Khimko. This is an open access article 
distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any 

medium, provided the original work is properly cited. 
 

 

 

Problems of Tribology, V. 26, No 1/99-2021,43-50 
 

Problems of Tribology 
Website: http://tribology.khnu.km.ua/index.php/ProbTrib 

E-mail: tribosenator@gmail.com 
 

DOI:  https://doi.org/10.31891/2079-1372-2021-99-1-43-50 

 

 

Evaluation of operational properties of aviation oils by tribological 
parameters 

 
O.O. Mikosianchyk, О.Ye. Yakobchuk, R. H. Mnatsakanov, A.M. Khimko 

 
National Aviation University, Ukraine 
E-mail: oksana.mikos@ukr.net 

 

 

Abstract 

 

The quality of aviation oils was evaluated online on the basis of  their lubricating, antifriction, 

rheological and antiwear properties in the friction contact. The use of the software and hardware complex for 

evaluation of operational characteristics of triboelements is offered. Approbation of the proposed methodology 

was performed on aviation oils SM-9. The increase in antifriction properties of  the ―Bora B‖ SM-9 oil was 

established to be due to the formation of limiting adsorption layers of lubricant on friction-activated contact 

surfaces, which are characterized by low shear stresses of the lubricant, and their structuring provides high 

effective viscosity in the contact at a level of 5142 Pa.s. It was revealed that at start-up the lubricant temperature 

is 20 
0
С and the mixed lubrication mode prevails, but with increasing the lubricant temperature to 100 

0
С the 

elastic-hydrodynamic (contact-hydrodynamic) lubrication mode dominates, then at maximum rotation speed of 

friction pairs the hydrodynamic lubrication mode dominates, regardless of oil temperature, which indicates the 

effective separation of the contact surfaces due to the formation of a lubricating layer between them. Analysis of 

the specific work of friction in the friction contact showed that the instability of this parameter evidences to 

intensification of destructive processes in the near-surface layers of metal and reduction in its wear resistance. 

The decrease in wear resistance of the lagging surface in the conditions of rolling with sliding for all types of 

investigated oils is due to the different directions of the friction force vector in the contact. In the course of 

operation of friction pairs in nonstationary conditions, the softening of the surface metal layers occurs, which has 

a positive effect on the tribological processes in the contact. 

The practical significance of the work consists in developing a methodology of analysis of lubricants, 

which makes it possible to more accurately evaluate their performance and provide recommendations for the 

choice of lubricant for specific friction units. 
 

Key words: aviation oils, lubricating layer, antifriction properties, lubrication mode, wear, 

microhardness. 

 

Introduction 

 

The reliability of mechanical systems is laid at the design stage, provided during the manufacture and 

confirmed during the operation of machines and mechanisms. Lubricants significantly affect the reliability. The 

current requirements for the reliability of tribological systems are associated with the qualitative improvement of 

lubricants and their components, as a rule, on the basis of in-depth analysis of the lubricating medium and the 

contact metal surface under friction. Nowadays the technology for production of lubricants and their components 
is intensively developing and improving. New lubricants on mineral and synthetic base are created, serious 

developments on optimization of component composition of oils and lubricants are conducted and their physical, 

chemical and operational properties are improved. 

First of all, yet at the design stage, the designer should be provided with a methodological base for not 

only selecting materials of machine parts according to strength criteria, but also for selecting lubricants, 

including assessment of temperature range of their operation, compatibility with friction pair materials, wear 

properties, bearing capacity of lubricating layer, tendency to form protective layers on the friction surfaces, etc. 

Lubricants, when optimally selected for a specific technical problem, can exert a marked effect at the 

expense of  saving energy, reducing wear and  expenses for maintaining, increasing the service life of machinery 

http://tribology.khnu.km.ua/index.php/ProbTrib
https://doi.org/10.31891/2079-1372-2021-99-1-43-39
file://rotation


44 Problems of Tribology 

 

and equipment, and finally, they can be a rational means of solving urgent ecological problems and environment 

protection [1]. 

Thus, the development of tools and methods for monitoring the behavior of lubricants and processes 

occurring in the friction contact, as well as substantiation of the criteria for their evaluation is an urgent task. 

 

Literature review 

 

The improvement of controlling and measuring devices and the rapid development of computer 

technology provide a real opportunity to study for the first time the tribological processes of formation of 
dissipative structures during friction at the atomic and molecular levels. For example, the SFA complex made it 

possible to measure film thickness to 0.1 nm and to record extremely small surface forces, which gives it 

significant advantages over other devices and thus allows one to use it as the main tool in the study of 

rheological, lubricating and antifriction properties of tribocontact at the nanolevel [2]. 

Modes and conditions of accelerated tests of motor oils in the engine have been proposed [3], which 

allow decreasing  the time for evaluation of operational properties of oils by 8 times, in line with providing high 

reliability of the results of determination of washing-dispersing and antiсarbon properties through selection and 

qualification tests of motor oils to be used  in forced transport diesels.  

Laboratory evaluation of physicochemical parameters, antiwear and antifriction properties of oils can 

confirm or refute the level of operational parameters declared by the manufacturer. In [4], based on analysis of 

data of industrial tests of G-Profi MSI Plus engine oil, it is shown that the oil has a sufficient resource of 

performance thanks to the balance of acid and alkali numbers along with effective viscosity, and this offers the 
possibility of prolongation  of the service break time while replacing motor oils in line with  the corresponding 

control of operational indicators. 

Thus, one of the current topical trends in the area of introducig new lubricants in production is the 

development of an algorithm for qualification tests concerning determination of the level of oil operational 

properties. The scope of methods for evaluating the qualitative characteristics of oils should include both 

laboratory studies and model stands or installations. 

In Ukraine, new technical specifications are being developed for a number of aviation lubricants. One of 

the most promising ones for production and introduction in practice is the mixture SM-9 [5] designed for use in 

gearboxes of helicopters in  winter.  It is composed of aviation oils AMG-10 and TSGip with a ratio of 1/3 to 

2/3. The AMG-10 oil is produced on the basis of deeply dearomatized waxy fraction obtained from products of 

the hydrocracking of mixture of paraffinic oils and consisting of naphthenic and isoparaffinic hydrocarbons. It 
contains thickening and antioxidant additives, as well as a special organic dye. Oil for hypoid transfers TSGip 

belongs to the group of universal oils with antiscoring additives of high efficiency and multipurpose action. It 

ensures the normal operation of hypoid gears under shock loads at contact stresses above 3000 MPa and oil 

temperatures in the volume up to 150 °C. 

As for aviation lubricants of domestic manufacturers, it is necessary to develop measures for the 

introduction of them in practice (stand, flight tests, operation under supervision, etc.), aimed at evaluating the 

operability of aircrafts using a new oil, establishing resource and application restrictions. Upon receiving 

positive test results at all stages, a new brand of oil can be included in the related operation instructions. 

 

Purpose  
 
The aim of the work is to evaluate online the quality of aviation oils taking into account their lubricating, 

antifriction, rheological and antiwear properties in the friction contact. 

 

Methodology for evaluating the operational properties of oils  

 

The study of lubricants was carried out with using a software and hardware complex (PAC) designed to 

evaluate the tribotechnical characteristics of triboelements [6]. PAC is a complex, which includes a friction unit, 

electronic unit and software "Friction", installed on a personal computer of  the IBM PC type. The software unit 

of mathematical data processing performs calculations according to a given calculation algorithm. The created 

program has a separate channel for visual assessment of the kinetics of changes in the main tribological 

indicators of the tribocontact in the online mode. 
Methods for determining the tribological characteristics of the friction unit with using PAC are as 

follows: 

‒ Lubricating properties (of hydrodynamic and non-hydrodynamic components of the lubricating film 
thickness) are determined by the method of voltage drop in the mode of normal glow discharge. According to 

this technique, the voltage drop across the lubricating layer is measured at a current of 2 and 4 A, then the 

thickness of the lubricating layer is determined from the calibration tables. 

‒ Antifriction properties of the contact are determined on the basis of data on the kinetics of changes in 
friction torque and subsequent calculation of the friction coefficient in the contact. 



Problems of Tribology 45 

 

‒ Rheological characteristics of lubricants (shear rate gradient, shear stress of lubricating layers, effective 
viscosity in the contact) are determined from the kinetics of changes in the thickness of the lubricating layer, the 

rolling speed of the leading and lagging surfaces and the lubricating layer temperature [7]. 

‒ Determination of the specific work of friction in the contact (through integrating the area outlined by 
the friction moment curve and choosing an arbitrary range of integration along on the x-axis at a certain selected 

time of operation, taking into account the kinetic energy of rotating parts). 

‒ Strength characteristics of the contact metal surfaces are determined according to GOST 22162-76 
(Method for determining the microhardness). 

Antiwear properties of lubricants are determined by measuring the indentation made by pressing the 
indenter of the device PMT-3 (GOST 27860-88. Parts of friction unit. Methods for measuring wear). 

 

Objects of research and experimental conditions 
 

Objects. Lubricants: sample 1 - oil "Bora B" SM-9 (TU U 19.2-38474081-017: 2018 with change 1 

"Transmission oils" Bora B ") and sample 2 – Kvalitet-Avia aviation oil mixture SM-9 (TU 0253-001-

49878493-2005 with changes 1-13). 

Material of friction pairs: rollers from steel 40ChN (analog of steel 3130H (USA), 1.5710 (Germany), 

40CrNi (China)), HRC 38, Ra 0.34 µm. Lubrication of the contact surfaces was provided through  immersing the 

lower roller in the lubricant bath. 

Experimental conditions. Friction mode: nonstationary conditions – cyclic operation in the start-up mode 

– stationary operation – braking – stop (Fig. 1). 
 

 
 

Fig. 1. Schematic representation  of tribosystem operation in nonstationary conditions of friction. 

Areas: І - start; ІІ - stationary work; III - braking; IV - stop. 

 

 Maximum rotation speed: 700 rpm for the leading surface and  500 rpm for the lagging surface.  Sliding 

30%. Friction path for one cycle: 91.845 m for the leading surface and 62.8 m for the lagging surface. Total 
friction path: 9184.5 m for the leading surface and 6280 m for the lagging surface. The maximum contact load 

by Hertz: 200 MPa.s . Number of cycles: 100 cycles. Oil temperature: 20 
0
C from the 1st to the 45th cycle; 

heating in the 20-100 
0
C range from the 46th to the 50th cycle; 100 

0
C from the 51st  to the 100th cycle. The 

duration of the cycle: 80 s. 

 

Results 

 

Let us analyze the kinetics of changes in the tribotechnical parameters of aviation oils in the course of 

operation in nonstationary friction conditions. 

Samples 1 and 2 are characterized by high antifriction properties in the investigated temperature range 

(Fig. 2). For sample 1, the average friction coefficient is 0.0183, regardless of the lubricant temperature, the 

friction coefficient is stable, the range of its oscillations is within 0.015…0.026. The increase in the friction 
coefficient through 58 - 60 cycles is due to the change in the nature of boundary layers with increasing lubricant 

temperature. For sample 2, the average friction coefficient is 0.0147, regardless of the lubricant temperature; the 

friction coefficient is unstable, the range of its oscillations is within 0.009…0.034. The established periodic 

increase/decrease in the friction coefficient during operation indicates the instability of tribotechnical processes 

in the friction contact. 

Let us compare the kinetics of changes in the lubricating properties of aviation oils in the tribological 

contact. 

The investigated oil "Bora B" SM-9 (sample 1) is characterized by effective lubricating properties both at 

start-up and at the maximum revolutions studied (Fig. 3). With increasing temperature in the tribological contact, 

the adsorption layer thickness decreases due to changes in their nature: the boundary layers of mostly physical 

nature are replaced by boundary layers of chemical nature, which are characterized by more effective antiwear 
properties. No failure of the lubricating layer during start-up and direct metal contact of the friction surfaces was 



46 Problems of Tribology 

 

fixed. At start-up, the lubricant temperature  was 20 
0
С and the mixed lubrication mode prevailed. With 

increasing the lubricant temperature to 100 
0
С the elastohydrodynamic (contact-hydrodynamic) lubrication mode 

dominated, which testifies to the effective starting properties of ―Bora B‖ SM-9 oil. At maximum speeds of the 

samples, the hydrodynamic mode of lubrication dominated, regardless of the oil temperature, which indicates the 

evident separation of the contact surfaces due to the formation of a lubricating layer. 

 

 
 

Fig. 2. The kinetics of change in the friction coefficient 

 

Kvalitet-Avia oil mixture SM-9 (sample 2) is characterized by effective lubricating properties at the 

maximum studied speeds, providing a hydrodynamic mode of lubrication. The total thickness of the lubricating 

layer for sample 2, on average, is 1.32 times less than that of sample 1 (Fig. 3). At start-up, instability of 

lubrication is revealed, 20% of cycles demonstrate a dry-semidry mode of lubrication, related to the long period 
of formation and adaptation of the lubricant boundary layers to nonstationary friction conditions. 

 

 
 
Fig. 3. Kinetics of change in the thickness of the boundary adsorption layers (hb) and the total thickness of the 

lubricating layer (ht)  in the course of operation. 

 

Since oils are used in helicopter transmission reducers, characterized by large contact loads and shear rate 

gradients, it is reasonable to analyze the rheological parameters of lubricants. 

The oil ―Bora B‖ SM-9 (sample 1) is characterized by efficient rheological properties. With it, the 
hydrodynamic mode of lubrication at maximum speeds of the cycle in the conditions of rolling with 30% sliding 

is provided owing to the high bearing capacity of the lubricant and the formation of hydro- and non-

hydrodynamic components of the lubricating layer thickness, which are characterized by low shear stresses equal 

to  13.89 MPa with a range of divergences within 10.91…18.85 MPa. 



Problems of Tribology 47 

 

Despite high rotation speed gradients in the contact, from 1.99.10
3
 to 2.26.10

5
 s

-1
, which arise at a 

maximum sliding velocity of 0.71 m/s in the conditions of rolling with sliding, the lubricant is characterized by 

high effective viscosity, on average 5142 Pa·s (Fig. 4). This indicates a high resistance of the oil components to 

destruction due to increasing shear rate gradient. The greatest decrease in the effective viscosity in the contact 

down to 378...914 Pa·s occurs at the beginning of increasing oil temperature, i.e., during 45 - 50 test cycles. This  

is caused by change in the nature of the boundary adsorption levels,  characterized by effective adaptation in a 

wide range of temperatures. 

Different changes in the rheological parameters in nonstationary lubrication conditions were established 

for the Kvalitet-Avia oil mixture of SM-9 (sample 2). First, the average shear stress of the lubricating layer is 
1.27 times less than in sample 1 and  equals 10.98 MPa. However, a wide range of discrepancies were revealed 

in the range of 5.19… .29.38 MPa for this lubricant, which is due to the long-term adaptation of the lubricant 

boundary layers to high shear rate gradients in the conditions of rolling with 30% sliding, which reach 1.17 · 10
3
 

to 7.2 · 10
5
 s

-1
. There is observed periodic destruction of the boundary layers in the friction contact during 

operation, which indicates a decrease in their antiwear properties. 

Second, the low tendency to structurization of the lubricant components on the friction-activated metal 

surface leads to a less pronounced dependence of the effective viscosity of the oil on the shear rate gradient: the 

average is at the level of 500 Pa·s. When the oil temperature increases to 100 
0
С, the effective viscosity first 

decreases to 80 Pa·s, but with further operation  of friction pairs increases to 600 - 800 Pa·s (Fig. 4). 

 

 
 

Fig. 4. The kinetics of change in the effective viscosity of oil (η) n the contact 
 

An important operational parameter of the tribosystem is the energy load on the friction contact, which 

can be evaluated from  the kinetics of changes in the specific work of friction, Afr. It depends on the type of 

lubricant, contact surface material and operation conditions of the tribosystem. 
The obtained experimental values of Afr for sample 1 in the range 1186…6328 J/mm

2
 indicate the normal 

operation conditions of the tribosystem (Fig. 5). With increasing oil temperature from 20 to 100 
0
C, the specific 

work of friction increases, on average, by 1.6 times, which indicates transition of the tribosystem to more 

complex conditions of friction. However, the investigated lubricant in such conditions provides realization of the 

hydrodynamic mode of lubrication in the contact and  high wear resistance for the metal. 

For sample 2, more intense energetic processes in the friction contact were established. The specific work 

of friction is unstable and characterized by a wide range of oscillations in the range of 1300…33430 J/mm
2
, 

regardless of the lubricant temperature. The failure to achieve a metastable state of the tribosystem in terms of 

energy can lead to intensification of destructive processes in the surface layers of the metal  and reduction in its 

wear resistance. 

 

 
 

Fig. 5. Kinetics of changes in the specific work of friction in the course of  operation 



48 Problems of Tribology 

 

 

One of the most important characteristics of oils during operation is their antiwear properties, so the 

establishment of regularities of  friction pair wear will make it possible to predict its durability and reliability. 

The total linear wear of the 40ChN steel rollers upon lubricating the friction pairs with oil is 4.9 μm and 

5.74 μm for samples 1 and 2, respectively (Fig. 6). The wear of the lagging surface is 2.38 (sample 1) and 1.9 

(sample 2) times greater than that of the leading surface, which is due, by the K.T. Trubina theory [8], to 

reducing the endurance limit of the lagging surface because of  the increase in the rate of fatigue destruction  in 

conditions of different directions of friction forces in the contact on the leading and lagging surfaces. 

 

 
 

Fig. 6. Wear of contact surfaces in the course of operation 

 

The wear intensity of  both the leading and lagging surfaces is characterized by low values, which 

indicates high wear resistance of the contact surfaces and effective antiwear characteristics of the oils studied 
(Table 1). In the case of  lubrication of friction pairs with sample 2, the wear intensity of the leading and lagging 

surfaces increases by 1.36 and 1.09 times, respectively, compared with sample 1. 

 

Таble 1 

 

Antiwear characteristics of aviation oils  

 

 

 

Indicator 

Lubricant material  

Sample 1  

Oil  «Bоrа B» SМ-9  

Sample 2  

Kvalitet-Avia oil mixture SM-9 

Wear of contact surfaces (steel 40ChN) after  100 cycles  

Total linear wear of the 

samples studied, µm  

4.9 5.74 

 

Wear, µm 

Leading surface  Lagging surface  Leading surface  Lagging surface  

1.45 3.45 1.97 3.77 

Wear intensity 1.57875·10
-10

  5.49363·10
-10

  2.14492·10
-10

  6.00318·10
-10

 

Wear resistance   6.33·10
9
  1.82·10

9
  4.66·10

9
 1.67·10

9
 

 Microhardness of the samples (steel 40ChN) 

Microhardness of surface 

before experiment , МPа  

 

4377 

 

4590 

 

4310 

 

4658 

Microhardness of surface 

after 100 cycles, МPа 

 

2764 
 

 

2758 
 

 

3118 
 

 

2914 
 

 

Since the lubricant components affect the near-surface layers of the metal by modifying them during 

friction, the strength characteristics of contact surfaces were evaluated. The reduction of microhardness of steel 

40ChN after 100 cycles was determined to be by 1.58 and 1.66 times for the leading and lagging surfaces, 

respectively, in the case of  lubricating with sample 1; and by 1.38 and 1.6 times for the leading and lagging 

surfaces, respectively, in the case of lubricating with sample 2. The hardening of metal surface layers  is due to 

the manifestation of the Rebinder effect, i.e., adsorption plasticization of solids under the action of oil 

surfactants. The thickness of the plasticized layer can be up to 0.1 μm. This phenomenon exerts a positive effect 

on tribological processes in the contact as it reduces the surface energy due to adsorption of the active 

components of the oil additive and  formation of boundary adsorption layers of both physical and chemical 

nature. This leads to increased wear resistance of the contact surfaces at the expense of reducing the resistance of 
the surface layer of the solid body to plastic deformation, facilitating plastic shear in the grains and the 

emergence of dislocations as well as forming finer granular structure. 



Problems of Tribology 49 

 

 

Conclusions  
 

A methodology for evaluating the operational properties of aviation oils taking into account their 

lubricating, antifriction, rheological and antiwear properties in the friction contact in the online mode has been 

developed. Based on studies of tribological characteristics of aviation oils, it was found that the oil "Bora B" 

SM-9 is characterized by more effective lubricating, antifriction, antiwear and rheological characteristics in 

nonstationary conditions of friction in the mode of rolling with 30% sliding compared with the aviation oil 

mixture SM -9. In particular, a comprehensive evaluation of tribological parameters of oil "Bora B" SM-9 
showed the stability of the friction coefficient in the start-stop mode, formation of boundary adsorption layers of 

lubricant on friction-activated contact surfaces, dominance of hydrodynamic lubrication at maximum speed, high 

effective viscosity in the  contact at low shear stresses of the oil layer and low wear intensity of friction pairs, 

which allows one to more accurately evaluate its operational characteristics. This, in turn, makes it possible to 

more accurately evaluate the quality of the oil and provide recommendations for the choice of lubricant for 

specific friction units. 

 

References 

 

1 Singh Y., Singh P., Sharma A., Choudhary P., Singla A., Singh N. (2018) Optimization of wear and 

friction characteristics of Phyllanthus Emblica seed oil based lubricant using response surface methodology. 

Egyptian Journal of Petroleum, 27 (4), 1145-1155.  
2. Israelachvili J. N. (2011) Intermolecular and surface forces, 3-rd ed., USA: Academic Press, 674. 

3. Bychkov V.Z., Hrytsiuk A.V., Zaitsev A.V., Klimenko N.V., Shcherbanenko G.V. (2005) Metod 

uskorennoy otsenki moyushchikh i antinagarnykh svoystv motornykh masel v dvukhtaktnom forsirovannom 

dizelnom dvigatele [Method for accelerated evaluation of the detergent and antinagar properties of engine oils in 

a two-stroke forced diesel engine]. Dvigateli vnutrennego sgoraniya, 1, 118-121. 
4. Korneev S.V., Pashukevich S.V., Savoskin A.S., Shirlin I.I. (2017) Izmeneniye kharakteristik 

motornogo masla pri ekspluatatsii dvigateley cummins avtobusnogo parka g. Omska [Сhange in the 

characteriistics of the engine oil during operation of the cummins engines of bus fleet in the city of Оmsk]. 

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5. https://bora.in.ua/ukraine_import/aviamasla/tsgip.html 

6. Mikosianchyk O.O. (2013) Patent 88748, Ukraine, IPC G01N 3/56. Prystrii dlia otsinky 

trybotekhnichnykh kharakterystyk triboelementiv [Device for estimating tribological characteristics of 

triboelements], 6, 4. 
7. Mikosianchyk O.O., Mnatsakanov R.G., Kindrachuk M.V. (2013) Patent 89261, Ukraine, IPC G01N 

11/00. Sposib otsinky dynamichnoi efektyvnosti vyazkosti mastylnykh materialiv v trybotekhnichnomu kontakti 

[Method for estimating dynamic efficiency of viscosity of lubricants in tribotechnical contact], 7, 4. 

8. Kurapov P.A., Novikov V.S., Efros D.G., Fedosh D.A. (2016) O mehanizme iznashivanija zubchatyh 

koles reduktornyh sistem gazoturbinnyh dvigatelej [On the wear mechanism of gear wheels of reduction systems 

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50 Problems of Tribology 

 

Мікосянчик О.О., Якобчук О.Є., Мнацаканов Р.Г., Хімко А.М. Оцінка експлуатаційних 

властивостей авіаційних олив за триботехнічними параметрами  

 

Проведена оцінка якості авіаційних олив з урахуванням їх змащувальних, антифрикційних, 

реологічних та протизношувальних властивостей в фрикційному контакті в режимі on-line. 

Запропоновано застосування програмно-апаратного комплексу для оцінки експлуатаційних 

характеристик трибоелементів. Апробація методики проведена на авіаційних оливах СМ-9. Встановлено 

підвищення антифрикційних властивостей оливи «Бора Б» СМ-9 за рахунок формування граничних 
адсорбційних шарів мастильного матеріалу на активованих тертям контактних поверхнях, які 

характеризуються низькими напруженнями зсуву мастильного шару, а їх структуризація забезпечує 

високу ефективну в'язкість в контакті на рівні 5142 Па·с. Проаналізовано, що при пуску, температура 

мастильного матеріалу 20 0С, переважає змішаний режим мащення, при зростанні температури 

мастильного матеріалу до 100 0С домінує еластогідродинамічний (контактно-гідродинамічний) режим 

мащення, при максимальних обертах пар тертя домінує гідродинамічний режим мащення, незалежно від 

температури оливи, що свідчить про ефективне розділення контактних поверхонь внаслідок утворення 

мастильного шару між контактуючими поверхнями. Аналіз питомої роботи тертя в фрикційному 

контакті показав, що нестабільність даного параметру свідчить про інтенсифікацію деструкційних 

процесів в приповерхневих шарах металу та зниження його зносостійкості. Встановлено зниження 

зносостійкості відстаючої поверхні в умовах кочення з проковзуванням для всіх типів досліджуваних 

олив, що обумовлено різновекторною направленістю сил тертя в контакті. При напрацюванні пар тертя в 
нестаціонарних умовах встановлено знеміцнення поверхневих шарів металу, що позитивно впливає на 

триботехнічні процеси в контакті.  

Практичне значення роботи полягає в розробленні методики аналізу мастильних матеріалів, що 

дозволяє більш точно оцінити їх експлуатаційні характеристики та надати рекомендації щодо вибору 

мастильного матеріалу для конкретних вузлів тертя.  

 

Ключові слова: авіаційні оливи, змащувальний шар, антифрикційні властивості, режим мащення, 

знос, мікротвердість