Rolling Contact Fatigue Behavior of Thermal-Sprayed Coating: A Review (original) (raw)
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Rolling contact fatigue of surface coatings—a review
Wear, 2002
The aim of this review is to survey the state of the art relating to the rolling contact fatigue (RCF) investigation of various overlay coatings and also, to ascertain the influence of design parameters such as the type of deposition process, coating material and thickness on the ...
Metal ..., 2022
Dynamic impact wear, i.e. contact between two components in the presence of high cyclic local loads, is a challenging failure mode that occurs in many mechanical applications. Many previous studies have confirmed that dynamic impact testing is suitable for evaluating the contact fatigue of thermal sprayed coatings. However, the effect of the test parameters on the resulting lifetime is unclear. The aim of this study describes the effect of the ball material used in the dynamic impact test on the resulting fatigue life of the HVOF thermal sprayed coating. Three test balls made of WC/Co alloy, Si3N4 silicon nitride and 440 C steel were chosen for this study. Dynamic impaction testing was carried out on the Cr3C2-NiCr coating, which was sprayed by HVOF on a 1.2376 high-speed steel substrate. The impact lifetime was described by the number of critical impacts, i.e. the number of impacts before coating fatigue occurs. Furthermore, the depth and volume of impact craters were measured. Using scanning electron microscopy (SEM), the surface of the impacts as well as the microstructure of the coating on the cross-section in the region of the impacts were observed. Furthermore, the mechanism of crack propagation in the coating and the microstructure of the indentor were investigated.
WIT transactions on engineering sciences, 2007
Impact testing is an efficient experimental procedure that enables the determination of the fatigue resistance of mono-and multilayer coatings deposited on various substrates, which is not possible with the common testing methods previously available. In this paper an advanced impact tester, capable of assessing the fatigue failure resistance of coatings working under cyclic loading conditions, is presented. The fatigue failure of the tested coating was determined by means of scanning electron and optical microscopy. The test results were recorded in diagrams containing the impact load versus the number of successive impacts that the tested coating can withstand.
Sādhanā, 2020
The application of coating gets exceptional importance since it improves the tribological properties of the contacting surfaces. Different input parameters like coating deposition processes, coating material properties and its thickness, use of lubricant and its additives, surface roughness and temperature affect the tribological properties and the rolling contact fatigue (RCF) life of coated rolling and sliding contact elements. In this paper, an attempt has been made to review for the clear understanding of the effect of these input parameters on the RCF life and tribological performance of coated rolling and sliding contact elements. It has been observed that coating deposition process must be chosen based on technical and economic aspects. Among the different techniques, thermal spraying technique is cost effective, and it also provides better bonding strength, which improves the RCF life in comparison with other techniques. Similarly, the effect of other input parameters has been reviewed and possible combination of the input parameters that help improve the performance of coated contacting elements summarized. Furthermore, the current status of research and the scope of future work to be carried out, in this area, have been outlined.
Journal of ASTM International
Dynamic impact-wear and coating fatigue at cyclic loading conditions demonstrates a very demanding failure mode, which occurs in a number of mechanical applications and it becomes very critical when the application concerns aggressive working environments. The coating impact testing is a novel experimental technique developed to investigate the fatigue behavior of coating-substrate compounds, which was not possible with the common testing methods previously available. The objective of this study is to investigate the influence of the impact load on the fatigue strength of thermal spray high velocity oxy-fuel ͑HVOF͒ coatings. Furthermore, the overall aim of the current research is to prove the reliability of the impact testing method to assess the coating lifetime against fatigue, to interpret the coating failure modes, and thereby to explore its capability, whether this nonstandard test can be used in industrial scale as a reliable technique in the development and optimization of fatigue resistant coatings. Based on the above method the current research provides experimental results concerning the coating fracture in terms of cohesive and adhesive failure modes. The fatigue strength of the tested coatings is determined in terms of fatigue-like diagrams by means of scanning electron and white light interference microscopy, as well as by electron dispersive x-ray analysis ͑EDX͒ at discrete loads and number of loading cycles. From the conducted experiments, it was shown that the optimum HVOF coating against fatigue is the WC-CoCr.
Fatigue Crack Growth in Bodies with Thermally Sprayed Coating
Journal of Thermal Spray Technology, 2015
Many applications of thermally sprayed coatings call for increased fatigue resistance of coated parts. Despite the intensive research in this area, the influence of coating on fatigue is still not completely understood. In this paper, the localization of crack initiation sites and the dynamics of crack propagation are studied. The resonance bending fatigue test was employed to test flat specimens with both sides coated. Hastelloy-X substrates coated with classical thermal barrier coating consisting of yttria stabilized zirconia and NiCoCrAlY layers. The strain distribution on the coating surface was evaluated by the Digital Image Correlation method through the whole duration of the fatigue test. Localization of crack initiation sites and the mode of crack propagation in the coated specimen are related to the observed resonance frequency. The individual phases of specimen degradation, i.e., the changes of material properties, crack initiation, and crack propagation, were identified. The tested coatings strongly influenced the first two phases, and the influence on the crack propagation was less significant. In general, the presented crack detection method can be used as a sensitive nondestructive testing method well suited for coated parts.
Effect of Burnishing on the Contact Fatigue of Regenerative Thermally Sprayed Coatings
Journal of KONES. Powertrain and Transport
This study of the resistance to contact fatigue of Ni-5%Al alloy coatings and Ni-5%Al-15%Al 2 O 3 composite coatings were evaluated. The coatings were prepared by flame spraying (Casto-Dyn DS 8000 torch) and plasma spraying (PN 120 plasma jet). The coatings were subjected to a finishing treatment: turning, burnishing and grinding. Depending on coatings phase composition and finishing treatment, the parameter mean values of surface roughness (Ra) were in the wide range of 0.28 to 2.61 m. The coatings after burnishing characterized by smallest of surface roughness. The largest value of the parameter Ra was observed in the case of coatings after turning. The presence of the reinforcing phase in the coating increases the surface roughness of thermally sprayed composite coatings. The hardness of coatings also depends on the finishing methods. The minimum hardness equal to 192 HV2 was found in the case of coatings of Ni-5%Al obtained by using a Casto-Dyn DS 8000 gas torch. Burnished Ni-5%Al-15%Al 2 O 3 coatings obtained by plasma spraying characterized by hardness 291 HV2. Resistance of fatigue surface of thermally sprayed coatings on a SCF (standing contact fatigue) test stand was assessed. The test was designed based on the guidelines of the PN-80/H-04324 Polish standard. During the fatigue tests were provided constant contact of co-acting parts, without slipping. Based on the survey it was found that the plasma sprayed coatings (PN120 plasma-jet) have a greater resistance to fatigue then the coatings obtained by flame spraying Casto-Dyn DS 8000 torch. Composite coatings of Ni-5%Al-15%Al2O3 are more resistant to contact fatigue, compared to the alloy coatings of Ni-5%Al. Burnishing increases the fatigue resistance of coatings when compared to turning. Burnished and polished surfaces are characterized by a similar contact fatigue resistance.
Investigating Effect of Industrial Coatings on Fatigue Damage
2011
Investigating Fatigue is one the most important factors in designing most mechanical structure. The reason is that, in many cases, the specimens of the structure break down without any warning or signal. Nano and micron's Coatings are finding more and more applications in industry such as aerospace, automotive, and naval industries. The present article has a purpose. Firstly, it intends to explore the influence of four industrial coatings, namely, hardened chromium, embellished chromium, hardened nickel, and warm galvanizing, all of which have the thickness value at micron levels on fatigue specimens. Moreover, it aims to find the most convenient coating. To achieve these purposes, the abovementioned coatings with the thickness of 13 & 19 were coated on standard specimens who were made of CK45 steel under the same conditions. Then, the S-N curve of each sample was attained empirically according to the standard fatigue testing. Specimens are simulated in the finite element analysis according to experimental conditions and then S-N curve of each sample was attained. Finally, comparing the S-N curves, the most appropriate coating is introduced for the delineated conditions and based fatigue results may be predicted damage of coating.
Tribologia, 2020
Fatigue cracking of thin hard anti-wear coatings occurs, among others, in the tribological contact of sliding friction pairs, in the top layers of cutting tools coatings, as well as in the surface of elements subjected to erosion processes. Coating fatigue wear is initiated as a result of cyclic interactions with micro-roughness of counterpart or other elements or particles that repeatedly impact the surface. The selection of appropriate coatings can increase the durability of machine components that are subjected to fatigue impact loads. The paper presents the results of tests on micro-impact fatigue wear of elements covered with single TiN and DLC coatings, as well as multi-layer (Ti/TiN)×8 type. Fatigue tests were carried out using the micro-impact method by cyclic impact of the surface of the coating with a diamond ball. The experiments were performed using a special laboratory stand. The correlation between fatigue life of coatings and their micromechanical properties such as Y...
FATIGUE PERFORMANCE OF THERMAL SPRAY COATINGS ON CARBON STEEL: A REVIEW
IAEME, 2019
This paper contributes to a review of the research of the fatigue behaviour of thermal spray coatings on carbon steel. Previous studies provide the experimental characterization of the fatigue resistance of coated carbon steel. Different coating powders were deposited to a different type of carbon steels. Also, S-N curves were drawn from axial- and rotating bending fatigue test to determine the fatigue strength or fatigue limit of the samples. Thermal spray coatings showed great improvement to the work hardening effect but worsen the fatigue life due to the inclusion of oxide and pores, the presence of stress concentrators, and high microcrack density. Moreover, the effects of the surrounding environment have also resulted in pros and cons towards the fatigue strength. An improvement, however, can be done with the shot peening treatment, which significantly increases the compressive residual stress at interfaces of coating/substrate. The high compressive residual stress could delay the crack nucleation, thus increasing the fatigue life of the coated part.