High Temperature Tribological Behavior Research Articles

Comparative analysis on high temperature tribological behaviour of additive manufactured and cast AlSi10Mg alloy

Abstract In recent years, additive manufacturing (AM) of AlSi10Mg, a material widely used in the aerospace and automotive sectors, has gained considerable interest for its ability to produce intricate shapes with improved mechanical properties. This proposed study aims to experimentally assess the high-temperature tribological performance of as-printed AlSi10Mg and compare it with traditionally cast AlSi10Mg to determine its suitability for high-temperature tribological applications. Samples of AlSi10Mg were manufactured via powder bed fusion, followed by tribological testing at elevated temperatures (30 °C, 100 °C, 200 °C, and 300 °C). The performance of both printed and cast AlSi10Mg pins was compared against an EN31 disc. The microstructure, worn surface, and wear debris of both printed and cast AlSi10Mg were examined using XRD and SEM with EDX analyses. As the load and temperature increase, both printed and cast AlSi10Mg materials demonstrate an increase in wear rate and friction coefficient. The wear rate of printed AlSi10Mg decreased by 60 % compared to cast AlSi10Mg at higher temperatures. There is a consistent trend in the coefficient of friction between printed and cast AlSi10Mg samples at low temperatures and loads. Abrasive wear predominantly occurs in both printed and cast AlSi10Mg samples at 30 °C within a load range of 10 to 20 N, while adhesive wear predominates in the same samples at temperatures ranging from 100°C to 300 °C with an applied load of 30 N. At low temperatures, smaller wear debris is observed, whereas at high temperatures and under a load of 30 N, larger wear debris is observed for both cast and printed AlSi10Mg samples.

Microstructure and high temperature tribological behavior of nickel-based superalloy with addition of revert

The recycling of revert plays a crucial role in cost-efficiency and green manufacturing of superalloy. In this study, optical microscopy, scanning electron microscopy coupled with energy dispersive spectroscopy, tensile test, and tribological analysis were employed to investigate the microstructure, mechanical properties, and tribological behaviors of vacuum induction melted superalloys of 100% original material (Sample 1) and 40% original material + 60% revert (Sample 2). Dry sliding tests were conducted at 300 and 730 °C. The addition of revert promotes microstructure refinement, hardness increase, and carbide formation, at the cost of 18.5% ductility loss. During the high-temperature dry sliding process, abrasive, adhesive, and oxidative wear mechanisms were observed on the contact surfaces. Sample 2 exhibited a lower wear rate and coefficient of friction at both 300 and 730 °C. Additionally, a more continuous and wear-resistant tribolayer was formed on the wear track of Sample 2, effectively mitigating matrix oxidation compared to Sample 1. At 730 °C, a thick tribolayer developed on the wear surface of Sample 2, characterized by a hard and wear-resistant glaze layer on the outermost surface. The continuous sliding induced matrix heating, which facilitates recrystallization in the subsurface of Sample 2, induced by increased inclusions and carbides from the revert. The analysis of wear debris further illustrated the variations of wear mechanism at different temperatures. These findings are meaningful for understanding the high-temperature behavior of superalloys and optimizing alloy recycling process.

Elevated Temperature Tribological Behavior of Duplex Layer CrN/DLC and Nano Multilayer DLC-W Coatings Deposited on Carburized and Hardened 16MnCr5 Steel

This study investigates the impact of temperature on the tribological performance of duplex layer CrN/DLC and nano-multilayers DLC-W coatings deposited using hybrid PVD-PECVD techniques on carburized and hardened 16MnCr5 discs cut from internal combustion engines valve tappets. Reciprocating dry sliding experiments were conducted at 25 °C, 150 °C, 200 °C, and 250 °C to analyze the high-temperature tribological behavior of the coatings. The wear mechanisms were characterized using SEM, EDS mapping, Raman spectroscopy, and nanoindentation. The lowest coefficient of friction was obtained for CrN/DLC at 25 °C. The CrN/DLC coefficients of friction (COF) increase with temperatures due to increasing adhesive wear. Similarly, DLC-W exhibited a comparable trend with increasing temperature from 25 °C to 250 °C. Both coatings’ wear resistance decreased with higher temperatures due to the transformation of sp3 C bonds to sp2 C bonds, facilitating the plastic deformation of the coatings and afterward of the substrate. The CrN/DLC displayed superior wear resistance to the DLC-W coating across all temperatures. The DLC-W multilayer coating showed poor wear resistance above 150 °C, being completely removed during the testing. Compared to both coatings, the uncoated 16MnCr5 discs exhibited higher coefficients of friction and wear rates at all temperatures. Predominant wear mechanisms observed in the coated discs were adhesive and abrasive. The study revealed a decrease in the coatings’ structural and mechanical properties with rising temperatures. Hard abrasive WC particles were identified as contributing to increased wear rates in the multilayer DLC-W coatings.

High-temperature tribological behavior of plasma sprayed GNPs-reinforced YSZ coating over 316L stainless steel

Despite numerous studies focusing on the use of stainless steel (SS316L) in high-temperature tribological applications, there remains a significant research gap regarding the improvement of its sustainability and lifetime in these harsh conditions. Herein, the plasma-sprayed graphene nanoplatelets (GNPs) reinforced yttria stabilized zirconia (YSZ) coating was deposited over SS316L to enhance its viability for high-temperature tribological applications. The coatings have been deposited using fused and crushed powder to improve the sintering resistance of the coatings. The structural and mechanical properties of coatings were observed using XRD, Raman, FE-SEM, and Vickers microhardness, respectively. The composite coating offered a significant improvement in the reduction of wear rate (∼45 % compared to YSZ coating) at 873 K and coefficient of friction by ∼51 % from 300 K to 873 K. Further, the findings were investigated by Raman spectroscopy, High-resolution transmission electron microscopy, and X-ray photoelectron spectroscopy analysis to understand the effect of GNPs reinforcement. This study provides a pathway to improve the applicability of SS316L for high-temperature (up to 873 K) tribological applications.

Tribological behavior of h-BN/Al2O3 self-lubricating composites in extreme environments–Part Ⅰ: Lubricating behavior and ultra-low friction coefficient mechanism in air environments from room temperature to 1200 °C

The high-temperature tribological behavior of the h-BN/Al2O3 self-lubricating composite ceramics demonstrated a temperature-dependent variation, with an ultra-low friction coefficient about 0.09 being achieved at 1000 °C in an air environment when countered with Si3N4 pins. The molten B2O3 phase can effectively accumulate and mix the free h-BN phase at the friction interface to form a high-temperature adaptive similar solid-liquid tribo-film, thus providing ultra-low friction coefficients for composites in high-temperatures air environments. Meanwhile, the in-situ generated Al5BO9 phase can efficaciously enhance the strength and wear resistance of the friction interface, furnish mechanical support for the solid lubrication layer and preserve its structural integrity and stability during high-temperature friction.

Effect of friction block thickness on the high-temperature tribological behavior of the braking interface of high-speed train

Tests on a high-speed train braking platform with friction blocks of different thicknesses revealed data on friction heat, wear, and friction-induced vibration and noise (FIVN). A finite element model (FEM) was developed using a finite element software, and then a thermal-mechanical-wear coupling simulation method was proposed to simulate the high-temperature wear of friction blocks. The results show that thicker friction blocks led to higher temperatures, eccentric wear, and increased wear debris, forming a stiff third body layer causing high-intensity FIVN. Thinner blocks showed better tribological properties and reduced FIVN. Although block thickness affects FIVN, the main frequency differences are minor. Therefore, friction block thickness should be considered as an important factor in brake pad design to manage high-temperature tribological behavior.

High-temperature tribological behavior of the Al/Mg/Cu multilayered composite produced by the severe plastic deformation

In the current research, the microstructure and wear behavior of Al/Mg/Cu multilayered composite at high temperatures were investigated. For this purpose, the Al/Mg/Cu composite was produced by the accumulative roll bonding (ARB) process and continued until the sixth pass at ambient temperature. The hot wear tests were performed at loads of 10, 20, and 40 N at 100, 150, and 250 °C for different passes. The findings demonstrated that with the increase of ARB passes, the wear rate decreased. So under 40 N at 100, 150, and 250 °C, the wear rate in the sixth pass decreased by 53 %, 65 %, and 76 %, respectively, compared to the first pass. The examination of the worn surfaces showed at 100 °C under high loads, fatigue wear was dominant. At 150 °C, oxidation was the main wear mechanism. The presence of oxidized grooves on the surface showed that the abrasive wear encouraged oxidation. At 250 °C under 40 N, inhomogeneous oxidation was the main wear mechanism of the samples. So that aluminum and magnesium regions were oxidized and copper areas remained un-oxidized like isolated islands.

High-temperature tribological behavior of high-entropy sublattice oxide, nitride, and diboride coatings

The tribological performance of sputtered (Al,Cr,Nb,Ta,Ti)N, ▪ , and ▪ coatings on steel substrates was compared against TiN in dry ball-on-disk and scratch tests in ambient air at 20°C, 400°C and 700°C. The (Al,Cr,Nb,Ta,Ti)N and TiN perform similar in all tests, with (Al,Cr,Nb,Ta,Ti)N showing higher oxidation and abrasion resistance. The adhesion of (Al,Cr,Nb,Ta,Ti)N is superior to TiN at 20°C, but worse at elevated temperature due to an earlier onset of recovery processes that increase the mismatch in coefficient of thermal expansion with the substrate. The ▪ is the most abrasion resistant coating at room temperature owing to its high hardness, but suffers from oxidation in hot air. Scratch tests yield a similar adhesion strength to TiN at 20°C, but the anisotropic lattice expansion and shrinkage of the hexagonal structure at elevated temperatures lead to early delamination in the scratch test. The ▪ also adheres poorly on the steel, resulting in quick delamination during all tests.

High-temperature tribological behaviour and machining performance of self-lubricant CrAlNAg coatings for dry milling operations

Tribological and machining performance of CrAlNAg coatings having different Ag content tested against AISI 1045 medium carbon steel were assessed. Wear track was evaluated by scanning electron microscopy and energy dispersive spectroscopy. 3D topography of wear track and ball counterpart was determined by non-contact type profilometer. The formation of different oxide phases on track was confirmed using Raman spectroscopy. CrAlNAg9 and CrAlNAg12 coatings were found beneficial in reducing material adhesion from counterpart thus providing protective layers to counterpart, whereas small addition of Ag did not provide any improvement on CrAlN coating performance. CrAlNAg9 coated milling inserts demonstrated best results in terms of reduction in chip temperature (∼17.5 %), cutting forces, surface roughness (∼47 %) and chip thickness (∼12.7 %) compared to uncoated inserts.

Mechanical, materials, and physicochemical effects on the high-temperature tribological behaviour of laser additive manufacturing AlCoCrFeNi2.1 eutectic high-entropy alloys

ABSTRACT The AlCoCrFeNi2.1 eutectic high-entropy alloys (EHEAs) were prepared using selective laser melting (SLM) to study the tribological properties at high temperatures, focusing on the complex mechanism of the friction process. The density of the SLM EHEAs is 99.70%. The lamellar and cellular structures are unevenly distributed at different locations. In situ XRD demonstrated the transition from BCC to FCC with increasing temperature. A large number of B2 particles are distributed in the BCC matrix. The fluctuation of the friction coefficient is closely related to the shape and size of the wear debris. The hardness of the alloy is ∼105 HV at 1000 °C. The wear rate first increases and then decreases with increasing temperature. The maximum thickness of the oxide film is 13.52 μm at 1000 °C and exhibits delamination. The combination of mechanical, materials and physicochemical effects during friction contributes to the excellent high temperature wear resistance.

High temperature tribological properties of the high-hardness wear-resistant Cu-Ni-Al-Sn coatings produced by laser cladding

The high-hardness wear-resistant Cu-Ni-Al-Sn coatings were fabricated by laser cladding, and the effect of Sn content on the microstructure, hardness and high temperature tribological behaviors of the coatings was investigated. The results revealed that the hardness of the coatings increased from 177.6 to 674.0 HV0.3 due to the strengthening of Cu9NiSn3, FeNi and NiSn precipitations. In addition, Sn plays an important role in improving the high temperature tribological properties of the coatings. At 25–200 ℃, Sn can form a low shear-stress film to reduce the friction coefficient and wear rate. When the temperature exceeds 300 ℃, a tribo-oxides layer containing SnO2, CuO and Fe2O3 forms on worn surfaces, which play a role in improving the tribological properties.

Study on High-Temperature, Ultra-Low Wear Behaviors of Ti6Al4V Alloy with Thermal Oxidation Treatment

Thermal oxidation (TO) is a simple and economical way to enhance the wear resistance of the Ti6Al4V alloy. The TO temperature has a very important effect on the tribological properties of the TiO2 layer formed. However, the impact of the oxidation temperature on the high-temperature tribological behavior of a TO-treated Ti6Al4V alloy is not clear. Therefore, the Ti6Al4V alloy was oxidized at 400 °C, 600 °C, and 700 °C for 36 h, and the sliding friction experiments were conducted at room temperature (RT) and 400 °C with a Si3N4 ball as the counter body to comparatively study the effect of the oxidation temperature on the high-temperature friction behavior of the TO-treated Ti6Al4V alloy. The results show that the TO treatment can effectively improve the wear resistance of the samples at both room and high temperatures. Among them, the oxidation-treated samples at 700 °C show the best wear resistance, with a reduction of 92.6% at high temperatures; the amount of wear loss at room temperature was so small that it was almost incalculable. At room temperature, the friction surface formed uneven agglomerate formations, resulting in an elevated coefficient of friction (CoF) compared to the untreated samples. At a high temperature, however, the CoF is reduced compared to the untreated samples due to the formation of a homogeneous transfer film in the wear area that is caused by the interaction of Si3N4 and oxygen.

Effect of the elevated temperature on the wear behavior of Laser Metal Deposition IN718 repairs

IN718, a nickel-based superalloy popular in aerospace, has good high-temperature mechanics/corrosion resistance. Laser Metal Deposition (LMD) repairs using IN718 are extensively explored, yet few studies delve into their tribological aspects. This research examines post-treated IN718 coatings, mimicking rapid repairs, investigating their high-temperature tribological behavior. Samples underwent tribological tests at diverse loads and temperatures. Results show the scanning strategy does not impact the wear behavior. At elevated temperatures, a glaze layer forms in the contact zone, impacting lubrication and surface protection based on its uniformity. Despite its advantageous lubricating ability, at 400°C and 50 N force, the oxidized debris layer lacks mechanical stability. IN718 LMD repairs manifest enhanced high-temperature wear resistance compared to ambient conditions, attributed to the glaze layer.

Experimental investigation of mechanical and tribological properties of AA7065- B4C nano-composite

The present study used the stir casting technique to create hybrid composites employing aluminium AA 7065 alloy for the matrix and boron carbide reinforcements. In order to study the high-temperature tribological behaviour of aluminium boron carbide composites, the pin-on-disc method with pin heating setup was adopted. As a supplemental reinforcing material, fly ash particles were used due to their exceptional mechanical, metallurgical, and tribological properties. Microhardness testing, microstructure analysis, and tensile testing were all carried out. The wear rate of hybrid composites was studied on load, sliding velocity, and temperature. Mechanical properties and particle distribution were vastly improved during the testing phase. Although the ductility of hybrid composites was down, their tensile and compression strengths increased dramatically. The surface morphology of the pin was analyzed using a high-resolution scanning electron microscope. The impact of wear parameters on wear rate was analyzed using analysis of variance.

High-temperature tribological behavior of nanolayered TiAlN/TiSiN coating deposited on WC-Co cemented carbide

In this study, high-temperature tribological behavior of nanolayered TiAlN/TiSiN coating was evaluated against the Al2O3 counter-body using a pin-on-disk tribometer. The coating was deposited on the WC-Co substrate, in an industrial unbalanced magnetron sputtering system. Tribological tests were conducted at room temperature, 500, 600, 700, and 760 °C, in air and nitrogen atmospheres. After the tests, the coating was examined using confocal microscopy, tactile profilometry, scanning electron microscopy, focused ion beam, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and secondary ion mass spectrometry. The coating retained its microstructure and mechanical properties after exposure to high temperatures. At lower temperatures coating exhibited abrasive and adhesive wear mechanisms, while at higher temperatures abrasive and oxidative wear mechanisms were observed. In high-temperature tests, AlO, TiO and SiO were detected inside of wear tracks, in both atmospheres. However, the oxide thickness was significantly lower in tests with nitrogen atmosphere. Additionally, the top of the oxide layer was enriched in AlO with respect to TiO and SiO. The enrichment of AlO was more pronounced in nitrogen atmosphere. The coating tested in air exhibited slightly higher and more unstable coefficient of friction (COF) values, than in nitrogen atmosphere. This is attributed to the increased oxidation in air atmosphere. At room temperature tests in nitrogen, the wear rate was approximately 3 times lower than in air. At higher temperatures the wear rate was lower than at room temperature, in both atmospheres, due to formation of protective oxides. However, with the increase in testing temperature the wear rate increased. The reason for such behavior is the loss of substrate's and coating's hardness at high temperatures, and thickening of the oxide layer which accelerated its removal. The latter effect is not so pronounced in nitrogen atmosphere due to thinner oxide layer, which agrees with the lower wear rate in nitrogen atmosphere at high temperatures than in air.

Effect of V doping on the high temperature tribological properties of (Ti1−xVx)3AlC2 solid solutions sliding against different counterparts

The effects of Al content and the counterface material on the high temperature tribological behavior and wear mechanism of (Ti,V)3AlC2 solid solutions were investigated. The friction coefficient of (Ti0.6V0.4)3AlC2 is reduced by 36.25% and 47.76% compared to Ti3AlC2 at room temperature and 800 °C respectively. When coupled with Al2O3 and ZrO2 balls at 800 °C, continuous smooth lubricating films composed of oxides formed by the tribochemical reaction lead to the lower friction coefficients. When coupled with Si3N4 and SiC balls, the wear rates are relatively low due to the formation of friction films containing SiOx.

Tribological behavior and wear mechanism of nanomultilayer AlCrN/AlTiSiN coatings at elevated temperatures

Wear resistance is a critical property of tool coatings for high-speed machining, which depends on mechanical properties and oxidation resistance of the coatings. Many works have demonstrated that AlTiSiN coating has good mechanical properties. Additionally, AlCrN coating exhibits excellent oxidation resistance. The multilayered structure has proved to improve comprehensive properties of the coatings. Therefore, AlCrN/AlTiSiN multilayer coating has a high potential to be used in machining applications. This paper focuses on the high-temperature tribological behavior of AlCrN/AlTiSiN multilayer coating. The results show that AlCrN/AlTiSiN coating exhibits good to acceptable wear resistance up to 800 °C. Meanwhile, AlCrN/AlTiSiN coating also displays the lowest friction coefficient of ∼0.5 and a wear rate of 1.8 × 10−6 mm3/N m at 800 °C, which is about 58.13% and 64.0% lower than that of AlCrN and AlTiSiN coatings, respectively. The imaging and composition analysis of the high-temperature wear tracks allowed for explaining the differences in wear mechanisms. At 800 °C, a dense thin tribofilm is formed on the surface of AlCrN/AlTiSiN coating, which acts as a glaze layer to impede wear. It provides a strategy for enhancing the wear resistance of monolayer coating in high temperatures, which combines the advantages of both high oxidation resistance of one layer and high hardness of the other layer.

Effect of interstitial carbides on tribological properties of Co21Cr21Fe21Ni21V14.5C1.5 high entropy alloy at elevated temperature

High-entropy alloys (HEAs) with high wear resistance at elevated temperatures are desired for applications like turbine engine blades and internal combustion engines. By reducing the proportion of transition metal elements, the interstitial carbide in the form of doped non-metallic element C can reduce the preparation cost of HEA and improve its mechanical properties. The effect of 1.5 at% carbon doping at different sintering temperatures on microstructure, mechanical properties, and high-temperature tribological behavior was systematically investigated. The compressive strength and strain rate of C-doped HEAs sintered at 1200 °C were 969 ± 21 MPa, 8.43 ± 0.36%, which was improved by solution strengthening and carbide pegging dislocations. The wear mechanisms of C0 alloy at high-temperature are mainly oxidation wear, adhesion wear and delamination wear, while the wear mechanism of C10 alloy is mainly abrasive wear, adhesion wear, fatigue wear and oxidation wear. The combined effect of VC, M23C6 and M7C3 carbides and σ phase plays the role of anti-wear lubrication at RT∼800 °C, and the tribo-chemical reaction generates Cr2O3, NiCr2O4, NiO, and other compounds with high-temperature stability and oxidation resistance to form a thin dense oxide glaze layer, resulting in better anti-wear and friction reduction performance of C-doped alloy than undoped alloy.

Effect of boriding on high temperature tribological behavior of CoCrMo alloy

In the present work, CoCrMo alloy surfaces were subjected to powder-pack boriding at 950 ℃ for 5-hour and 7-hour treatment periods. The obtained boride layers were characterized with scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, nanoindentation and high temperature wear tests. Characterization results show that boride layers are composed of CoB, Co2B, CrB and Co2MoB2 phases. Up to 4-fold increase is achieved in nanohardness values due to the boride layers in addition to increased elastic moduli. Increased surface hardness coupled with the high temperature stability of boride layers led to nearly 12, 7 and 10-fold increase in the wear resistance of CoCrMo alloys, worn at room temperature, 250 ℃ and 500 ℃, respectively.

Influence of boron contents on mechanical properties and high-temperature tribological behavior in (AlCrNbTiB)N coatings

Various boron contents of AlCrNbTiBN coatings were prepared by radiofrequency reactive magnetron cosputtering on both 304 stainless steel and 100 silicon substrates. Boron-doped AlCrNbTiN coatings resulted in a dense structure and a decrease in the grain size. As compared to boron-free coatings, the hardness of AlCrNbTiBN coatings increased from 25.8 to 31.1 GPa at a boron content of 3.3 at. %. The AlCrNbTiBN coatings exhibited favorable hardness due to the increased dense structure, defect density, grain refinement, and solid solution strengthening. The wear test at 700 °C showed that coatings without boron reveal three times the wear rate than those coatings doped with boron. In this study, the multicomponent (AlCrNbTiBN) coating demonstrated favorable mechanical and tribological properties. This implies that AlCrNbTiBN coatings might provide promising applicability in the wear-resistant field at high temperatures. Furthermore, boron-doped multicomponent nitride coating appears to enhance coating’s mechanical properties and wear resistance, indicating potential development in the near future.