Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine
Abstract
:1. Introduction
2. Materials and Methods
2.1. Characteristics of Monitored Engine Components
2.1.1. Camshaft Material
2.1.2. Crankshaft Material
2.2. Characteristics of Meters and Equipment
2.2.1. Roughness Measurement
2.2.2. Microhardness Measurement
2.3. Measurement Characteristics
3. Results
3.1. Camshaft Roughness Measurement Results
3.2. Results of Measurements of Roughness of Connecting Rod Pins
3.3. Results of Microhardness Measurements
3.3.1. Camshaft
- In the course of the microhardness of the cams, in comparison with the values of the new camshaft, the hardened layer on the worn cams is significantly thicker, up to 1.5 mm, which is also evident from the graphical representation shown in Figure 12.
- The smallest measured hardness (556 HV0.5) was found for the exhaust cam from the second cylinder. Given these facts, we can state an undesirable connection of the pitting with the lubricant, where the lubrication failed similarly, as with the crankshaft. Subsequently, due to insufficient lubrication, the surface of the material overheated to the tempering temperature, and, thus, the hardness of the cams decreased.
- From the graph in Figure 12, it is possible to see the zone of the heat-treated layer with the transition to the hardness of the base material of the individual cams. Deviations in the position of the residual microhardness are affected by the degree of wear of the individual cams.
- It can also be stated that the technology of production of the old and the new cams was not identical, as the new cam has a significantly thinner hardened layer, which ultimately leads to faster wear in the engine friction nodes. These facts are also apparent from Figure 12.
- Using regression analysis, we experimentally demonstrated from a mathematical point of view that the hardness can also be expressed by polynomial function 3 of a row with a high value of the coefficient of determination R2, which is shown in Figure 13, Figure 14, Figure 15, Figure 16 and Figure 17, where the regression equations for the individual cylinders are also given, for the exhaust and intake cams. These statements show that the polynomial regressions used indicate a decrease in the microhardness of the monitored objects, and a more pronounced forest is observed on the new camshaft.
3.3.2. Crankshaft
3.4. Results of Microscopic Analysis
4. Conclusions
- The monitored components of the camshaft, on which we measured microhardness values of less than 550 HV on the surface, were clearly heated above the tempering temperatures of the materials. Based on the above facts, due to the heating of the material to a high temperature, there was a subsequent gradual cooling and tempering of the material. The tempering caused the material structure to soften to lower microhardness values, which is unacceptable mainly due to the service life of the monitored friction nodes. A lower value of microhardness in the zone of the heat-treated layer, with the transition to the base material, is one of the possible causes of wear, which we observed on the surfaces of the friction nodes. The wear of rotating parts results in complex mechanisms and various other factors that must be taken into account.
- From the measured values of microhardness according to Vickers, it can be observed that the exhaust cam from the second cylinder was so thermally affected that the material was tempered by the effect of which the hardness decreased to a value of up to 556 HV. Compared to the new cam, whose hardness reached a value of about 700 HV, the hardness drop in the new cam was rapid and incompatible with the prescribed values of the hardened layer, where the heat-treated layer was up to 1.5 mm thinner than that of the original camshaft from primary production.
- Material loosening also occurred on the connecting rod pins of the crankshafts at cylinders 1 and 4. Here, the values of microhardness decreased due to the tempering of the material to values of about 350 HV. Compared to cylinders 2 and 3, which achieved microhardness values in the range of 550–640 HV, this is an extraordinary decrease of almost 50%. The roughness analysis of the connecting rod pins confirmed the greatest wear, which was found on the cylinders with the lowest hardness, i.e., the first and fourth cylinders.
- When comparing the microhardness of the worn cams on the used camshaft and the new camshaft, it can be observed that the hardened layer of the new cam from the secondary production has a significantly thinner thickness compared to worn cams. From this finding, it can be stated that spare parts from secondary production are not produced in the same quality or with the same technology as the original parts from primary production.
- We also found support for the difference between the production technology in the production of the used and the new camshafts by carrying out a microscopic analysis of the materials of the examined objects. The new cam has a significantly thinner hardened layer, which ultimately leads to faster wear in the engine’s friction nodes.
- We also supported our findings with a mathematical expression of the measurements of individual cams and connecting rod pins. From the mathematical aspect, we experimentally proved the suitability of using regression analysis; thus, the hardness can be expressed by a polynomial function of the third row, where the results have a high value of the coefficient of determination R2. These statements show that the polynomial regressions used indicate a decrease in the microhardness of the monitored objects, and a more significant decrease was observed on the new camshaft.
- Based on all the results from the experiments, it is possible to expect more comprehensive information, especially in terms of roughness and microhardness of the materials used for functional pairs of friction nodes, which can help in the study of suitable materials for the production of monitored components used in automotive industry.
- One aspect of our conclusion points to the fact that, in the production process, it is necessary to follow the production procedure, which, in this case, is the chemical/thermal treatment of functional parts in order to avoid different properties of surface layers. The production of spare parts (either of base materials or of surface-reinforced layers) from secondary production should have the same qualitative features. Another aspect of our conclusion is the recommendation to shorten the oil change intervals to a maximum of 10,000–15,000 km in heavy traffic (urban cycle) or to apply oil additives enabling the solubility of combustion contaminants already in new vehicles, thus reducing the possible contamination of the oil by abrasive flue gas particles. These main aspects would significantly reduce the wear of functional pairs and prolong the technical lifespan of engines.
Author Contributions
Funding
Institutional Review Board Statement
Informed Consent Statement
Data Availability Statement
Conflicts of Interest
References
- Dayanç, A.; Karacaa, B.; Kumruoglu, L.C. Improvement of Tribological Properties of Steel Camshaft by Plasma Nitriding. Acta Phys. Pol. A 2019, 135, 786–792. [Google Scholar] [CrossRef]
- Stephens, R.I.; Fatemi, A.; Stephens, R.R.; Fuchs, H.O. Metal Fatigue in Engineering, 2nd ed.; Wiley-IEEE: Hoboken, NJ, USA, 2000; p. 496. [Google Scholar]
- Zhou, R.S.; Cheng, H.S.; Mura, T. Micropitting in Rolling and Sliding Contact Under Mixed Lubrication. J. Tribol. 1989, 111, 605–613. [Google Scholar] [CrossRef]
- Shiozawa, Y.; Morii, S.; Nishino, S.; Lu, L. Subsurface crack initiation and propagation mechanism in high-strength steel in a very high cycle fatigue regime. Int. J. Fatigue 2006, 28, 1521–1532. [Google Scholar] [CrossRef]
- Bai, L.; Sun, J.; Zhang, P.; Khan, Z.A. Friction Behavior of a Textured Surface against Several Materials under Dry and Lubricated Conditions. Materials 2021, 14, 5228. [Google Scholar] [CrossRef]
- Wong, V.W.; Tung, S.C. Overview of automotive engine friction and reduction trends–Effects of surface, material, and lubricant-additive technologies. Friction 2016, 4, 1–28. [Google Scholar] [CrossRef] [Green Version]
- Dayanç, A.; Karacaa, B.; Kumruoglu, L.C. Plasma Nitriding Process of Cast Camshaft to Improve Wear Resistance. Acta Phys. Pol. A 2019, 135, 793–799. [Google Scholar] [CrossRef]
- Chen, J.; Zuo, Z.; Zhou, S.; Wang, X.; Chen, Y.; Ling, G. Study on the Compressive Stress Retention in Quenched Cam of 100Cr6 Steel Based on Coupled Thermomechanical and Metallurgical Modeling. Materials 2021, 14, 5912. [Google Scholar] [CrossRef] [PubMed]
- Dobrenizki, L.; Tremmel, S.; Wartzack, S.; Hoffmann, D.C.; Brögelmann, T.; Bobzin, K.; Bagcivan, N.; Musayev, Y.; Hosenfeldt, T. Efficiency improvement in automobile bucket tappet/camshaft contacts by DLC coatings—Influence of engine oil, temperature and camshaft speed. Surf. Coat. Technol. 2016, 308, 360–373. [Google Scholar] [CrossRef]
- Yamaguchi, E.S.; Tanaka, G.A.; Matsumoto, K. Problems and Opportunities Regarding the Lubrication of Modern Automotive Engines. In Automotive Lubricants and Testing; Tung, S., Totten, G., Eds.; ASTM International: West Conshohocken, PA, USA, 2012; pp. 191–213. [Google Scholar] [CrossRef]
- Timofeeva, L.A.; Timofeev, S.S.; Fedchenko, I.I.; Dyomin, A.Y. Increasing the Wear Resistance of Reworked Parts of Transport Engines. J. Frict. Wear 2017, 38, 13–16. [Google Scholar] [CrossRef]
- Geels, K.; Fowler, D.B.; Kopp, W.U.; Michael, R. Metallographic and Materialographic Specimen Preparation, Light Microscopy, Image Analysis and Hardness Testing; ASTM International: Lancaster, PA, USA, 2007; p. 743. [Google Scholar]
- Mourelatos, Z.; Li, J.; Pandey, V.; Singh, A.; Castanier, M.; Lamb, D.A. A Simulation and Optimization Methodology for Reliability of Vehicle Fleets. SAE Int. USA 2011, 4, 883–895. [Google Scholar] [CrossRef]
- Cyriac, F.; Xin Yi, T.; Poornachary, S.K.; Chow, P.S. Effect of temperature on tribological performance of organic friction modifier and anti-wear additive: Insights from friction, surface (ToF-SIMS and EDX) and wear analysis. Tribol. Int. 2021, 157, 106896. [Google Scholar] [CrossRef]
- Blanchard, P.; Nigarura, S.; Trasorras, J.R.L.; Wordsworth, R. Assembled Camshaft with Sintered Cam Lobes: Torsional Fatigue Strength and Wear Performance; SAE International: Warrendale, PA, USA, 2000. [Google Scholar] [CrossRef]
- Kuş, A. Implementation of 3D Optical Scanning Technology for Automotive Applications. Sensors 2009, 9, 1967–1979. [Google Scholar] [CrossRef]
- Saridemir, S. The effect of dwell angle on vibration characteristics of camshaft bearing housings. J. Mech. Sci. Technol. 2013, 27, 3571–3577. [Google Scholar] [CrossRef]
- Scott, R. Basic Wear Modes in Lubricated Systems. Mach. Lubr. 2008, 7. Available online: https://www.machinerylubrication.com/Read/1375/wear-modes-lubricated (accessed on 18 November 2021).
- Umar, M.; Mufti, R.A.; Khurram, M. Effect of flash temperature on engine valve train friction. Tribol. Int. 2018, 118, 170–179. [Google Scholar] [CrossRef]
- Götze, A.; Makowski, S.; Kunze, T.; Hübner, M.; Zellbeck, H.; Weihnacht, V.; Leson, A.; Beyer, E.; Joswig, J.-O.; Seifert, G.; et al. Tetrahedral Amorphous Carbon Coatings for Friction Reduction of the Valve Train in Internal Combustion Engines. Adv. Eng. Mater. 2014, 16, 1226–1233. [Google Scholar] [CrossRef]
- Burdzik, R.; Konieczny, Ł.; Stanik, Z.; Folęga, P.; Smalcerz, A.; Lisiecki, A. Analysis of impact of chosen parameters on the wear of camshaft. Arch. Metall. Mater. 2014, 59, 957–963. [Google Scholar] [CrossRef] [Green Version]
- Akhmetzyanov, I.R.; Nikishin, V.N.; Barylnikova, E.P.; Kulakov, O.A. Investigation of the Thermal Tension of the Bearings of the Crankshaft of an Internal Combustion Engine. HELIX-Sci. Explor. 2019, 9, 5296–5302. [Google Scholar] [CrossRef]
- Tominaga, Y.; Kim, J.; Pyun, Y.; Kayumov, R.; Kim, J.; Woo, J. A study on the restoration method of friction, wear and fatigue performance of remanufactured crankshaft. J. Mech. Sci. Technol. 2013, 27, 3047–3051. [Google Scholar] [CrossRef]
Parameters | Values |
---|---|
Stroke volume | 1397 cm3 |
Power | 50 kW at 5000 min−1 |
Torque | 120 Nm at 2500 min−1 |
Fuel type | Natural 95 (E10) |
Mixture preparation | Multi Point Injection |
Number of cylinders | 4 |
Number of valves | 8 |
Engine timing | OHV |
Engine type | I |
Engine mounting | front across |
C | Mn | Si | P | S | Cr | Ni | Cu |
---|---|---|---|---|---|---|---|
0.52–0.6 | 0.5–0.8 | 0.15–0.4 | ≤0.04 | ≤0.04 | ≤0.25 | ≤0.3 | ≤0.3 |
Yield Strength (MPa) | Ultimate Strength (MPa) |
---|---|
480 | 750–900 |
C | Mn | Si | P | S | Cr |
---|---|---|---|---|---|
0.35–0.42 | 0.5–0.8 | 0.17–0.37 | ≤0.04 | ≤0.04 | 0.8–1.1 |
Yield Strength (MPa) | Ultimate Strength (MPa) |
---|---|
785 | 981–1177 |
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Bernát, R.; Žarnovský, J.; Kováč, I.; Mikuš, R.; Fries, J.; Csintalan, R. Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine. Materials 2022, 15, 158. https://doi.org/10.3390/ma15010158
Bernát R, Žarnovský J, Kováč I, Mikuš R, Fries J, Csintalan R. Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine. Materials. 2022; 15(1):158. https://doi.org/10.3390/ma15010158
Chicago/Turabian StyleBernát, Rastislav, Jozef Žarnovský, Ivan Kováč, Rastislav Mikuš, Jiří Fries, and Radoslav Csintalan. 2022. "Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine" Materials 15, no. 1: 158. https://doi.org/10.3390/ma15010158