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(a) Nanoindentation hardness and Young's modulus, and (b) calculated H/E and H 3 /E* 2 values of TiC/a-C coatings deposited at different substrate bias voltages.
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The paper will present the state-of-art in the process, structure and properties of nanostructured multifunctional tribological coatings used in different industrial applications that require high hardness, toughness, wear resistance and thermal stability. The optimization of these coating systems by means of tailoring the structure (graded, superl...
Citations
... The feeding wire is introduced in the arc which is further passed through the nozzle with the help of highly pressurized gas resulting in the formation of a coating layer on the substrate. [35] Transition metal nitrides-based thin films have been widely used for improving the hardness and wear resistance properties [39][40][41][42][43][44][45]. Moreover, they also provide enhanced corrosion and oxidation resistance properties even at high temperatures [46][47][48]. ...
Ni-based superalloys and thin films have drawn the attention of researchers because of their extraordinary properties. In particular, Nickel Aluminides like Ni3Al thin films show excellent mechanical and tribological properties. They are good candidates for high-temperature applications as they show excellent corrosion and oxidation resistance properties. Several researchers have synthesized Ni3Al thin films via Chemical vapor deposition methods (CVD) and physical vapor deposition methods (PVD). Most of them have synthesized Ni3Al thin film via magnetron sputtering because of microstructural homogeneity and less contamination achieved by this process. To achieve better properties of these films, many alterations in terms of deposition parameters and doping have been experimented by researchers. This work reflects the review of work done in the area of depositing Ni3Al-based thin films via different techniques for high-temperature applications.
... The substrate bias is also a tool to manipulate the energy transfer to the growing film, and its effect on the thin film properties has been largely investigated. The application of a bias voltage can significantly improve the thin film hardness, and has been associated with a grain refinement, improved film density, change in the mean grain separation, and disruption of the growth of the columnar structure [118,119]. Hu et al. [83] reported that the coating prepared at An alternative way to influence the energy and the flux intensity of impinging ions on a surface is by varying the target to substrate distance. The optimal substrate to target distance for the deposition of a good coating quality changes with the applied substrate bias. ...
Titanium carbide (TiC) coatings are widely used in several industrial applications, including tooling and tribological applications. These materials are used due to their mechanical, tribological and wear resistance properties, and chemical inertness. Hard TiC coatings are conventionally deposited using chemical vapor deposition techniques at temperatures, in the range of 1000 °C, which limits its application to temperature sensitive substrate materials. Therefore, plasma enhanced chemical vapor deposition has been utilized as an alternative deposition technique, showing good coating performance at temperatures as low as 500 °C. Recent technology developments have seen the emergence of high-power impulse magnetron sputtering (HiPIMS) as a promising approach to deposit high quality TiC coatings at ambient temperatures, thus making the use of new substrate materials and new applications possible.
The present article introduces magnetron sputtered TiC-based coatings with an emphasis on their structural, mechanical and tribological properties. An overview of the most relevant technological approaches for the development of binary and ternary TiC-based coatings over recent decades is presented. The relationship between the deposition parameters and the final coating properties is highlighted and discussed. Steering towards ternary TiC-based system have shown to improve the coating properties. In this light, several chemical elements have been used resulting in the formation of various coating structures including metastable solid solution, binary and/or ternary phases, or mixtures thereof. The benefit of adding a third element is discussed and its impact on the coating properties is highlighted. Finally, new outlook for potential applications is presented.
... As seen in Fig. 4, the CrTiBN coatings showed a more compact structure with finer nanograins in comparison to CrTiN coatings. According to Hall-Petch effect, crystals refinement could make a contribution to the hardness improvement of coatings [49]. Figure 5 shows a typical acoustic emission-load graph of CrN, CrTiN and CrTiBN coatings, which is closely related to coating fracture. ...
CrN, CrTiN and CrTiBN coatings were deposited on Si(100) and 316L stainless steel substrates by unbalanced magnetron sputtering system, and their microstructures, mechanical and tribological properties were characterized systematically. The results showed that CrN coatings consisted of CrN nanograins. After doping Ti and B elements, there mainly existed as TiN0.3 nanograins and amorphous BN phases for CrTiN coatings and CrTiBN coatings. When sliding against SiC balls in water, CrTiN coatings exhibited the best wear resistance among three kinds of coatings due to the great mechanical properties and the highest adhesion strength to substrates. Although the CrTiBN/SiC tribopair exhibited lower friction coefficient (0.18) than the CrTiN/SiC tribopair (0.26), the corresponding specific wear rate was higher due to the serious delamination. When three kinds of coatings slid against SUS440C balls, the CrTiBN coatings showed the lowest friction coefficient and the lowest specific wear rate simultaneously.
... As can be seen from Fig. 3, the Cr 2p spectra can be decomposed into peaks corresponding to the following energy values: 574.2, 575, 576, 583.5, 584.2, and 585.0 eV. In the XPS spectrum of sample S1, the peak located at 574.2 eV can be attributed to Cr-Cr [24] and Cr-B [25] bonds, while this peak for sample S4 corresponds to Cr-N bonds of CrN [20]. The peaks at 575 and 576 eV correspond to Cr-N bonds of Cr 2 N [20,25]. ...
... In the XPS spectrum of sample S1, the peak located at 574.2 eV can be attributed to Cr-Cr [24] and Cr-B [25] bonds, while this peak for sample S4 corresponds to Cr-N bonds of CrN [20]. The peaks at 575 and 576 eV correspond to Cr-N bonds of Cr 2 N [20,25]. At the same time, the peak at 576 eV can also be a reflection of Cr-O bonds in Cr 2 O 3 [26]. ...
... With addition of nitrogen, the intensity of this peak substantially decreased and an intense peak that most likely corresponds to B-N bonds was formed. The peak at 190.4 eV is due to the presence of B-N and/or B-O bonds [25,33]. The peak at 191.5 eV is attributable to B-N bonds in h-BN [34]. ...
... Boron doping for CFUBMS coatings was investigated mainly for the ternary Ti-B-N and Cr-B-N coatings [40][41][42][43]. Presumably, boron doping of more complex Cr-Al-Ti-N coating might provide considerable improvement in microstructural and mechanical aspects. ...
Boron and oxygen-doped Cr–Al–Ti–N coatings were deposited by closed field unbalanced magnetron sputtering (CFUBMS) of TiB target manufactured by self-propagating high-temperature synthesis, and Ti, Cr, and Al targets. To evaluate the influence of doping elements, as-deposited coatings were studied by glow discharge optical emission spectroscopy (GDOES), SEM, XRD, and optical profilometry. Mechanical properties were measured by nanoindentation and tribological, abrasive and electrochemical testing. The introduction of boron suppresses columnar growth and leads to structural refinement and a decrease of coating’s surface roughness. The addition of 2.3 at.% boron results in the highest mechanical properties: hardness H = 15 GPa, stable friction coefficient f = 0.65, and specific wear Vw = 7.5 × 10−6 mm3N−1m−1. To make the coating more visually appealing, oxygen was introduced in the chamber near the end of the deposition cycle. Upper Cr–Al–Ti–B–O–N layers were studied in terms of their composition and coloration, and the developed two-layer decorative coatings were deposited on cast metallic art pieces.
... 8,9 . The addition of Al to the CrN lattice, building up a substitutional solid solution with Cr and having the general stoichiometry of Cr 1−x Al x N, can improve the mechanical properties, thermal stability, and wear behavior of CrN-based films [10][11][12] . ...
Due to their applicability for manufacturing dense, hard and stable coatings, Physical Vapor Deposition (PVD) techniques, such as High Power Impulse Magnetron Sputtering (HiPIMS), are currently used to deposit transition metal nitrides for tribological applications. Cr-Al-N is one of the most promising ceramic coating systems owing to its remarkable mechanical and tribological properties along with excellent corrosion resistance and high-temperature stability. This work explores the possibility of further improving Cr-Al-N coatings by modulation of its microstructure. Multilayer-like Cr1−xAlxN single films were manufactured using the angular oscillation of the substrate surface during HiPIMS. The sputtering process was accomplished using pulse frequencies ranging from 200 to 500 Hz and the resulting films were evaluated with respect to their hardness, Young’s modulus, residual stresses, deposition rate, crystallite size, crystallographic texture, coating morphology, chemical composition, and surface roughness. The multilayer-like structure, with periodicities ranging from 250 to 550 nm, were found associated with misorientation gradients and small-angle grain boundaries along the columnar grains, rather than mesoscopic chemical modulation of the microstructure. This minute modification of microstructure along with associated compressive residual stresses are concluded to explain the increased hardness ranging from 25 to 30 GPa, which is at least 20% over that expected for a film of the same chemical composition grown by a conventional PVD processing route.
... Thus, the carbon element perturbs the normal crystal arrangement of chromium nitrides. In addition, they transform into chromium carbonitride by the appearance of (111) and (131) Cr 3 N 0.6 C 0.4 at 41.02°and 51.20°, respectively (cubic structure, JCPDS 01 0892540) [25][26][27][28]. This agrees well with earlier works, where carbides and carbonitrides have been successfully formed from transition-metal-nitride-based thin films deposited on high carbon steel [17,21]. ...
... This gives additional evidence to support the bonding of N to Cr after annealing treatment at 900°C and it is maybe due to the higher electronegativity of nitrogen [25]. These results mean that CrN and Cr 2 N coexist in the sample as shown from the XRD analysis (Fig. 4) [26,27]. As shown in Fig. 6.c, the C1s peak, can be fitted into two peaks, which centre on 282.98 eV and 284.34 eV corresponding to C-Cr and sp 2 C-C, respectively presenting the Cr 7 C 3 and free carbon [25,28]. ...
Chromium nitrides were deposited by RF reactive magnetron sputtering from a Cr target on high carbon steel substrates XC100 (1.17 wt% carbon) in a N2 and Ar gas mixture. In order to investigate the formation of chromium nitrides, carbide and carbonitride compounds were subjected to vacuum annealing treatment for 1 h at various temperatures ranging from 700 to 1000 °C. The samples were characterized by EDS, XPS, XRD, SEM, nanoindentation and tribometry. The results showed the emergence of Cr2N and CrN during the early stages of annealing and the appearance of chromium carbonitride phases only at 900 °C. The (111) preferred orientation of the fcc CrN phase was changed to (002) at 900 °C in parallel with the appearance of chromium carbides. Nanoindentation tests revealed a gradual increase of the Young's modulus from 198 to 264 GPa when increasing the annealing temperature, while the hardness showed a maximum value (H = 22.4 GPa) at 900 °C. The low friction coefficient of the CrCN coating against a 100Cr6 ball was approximately 0.42 at 900 °C. The enhancement of mechanical and tribological properties was attributed to the stronger bonding CrC at the CrN/XC100 interfaces as confirmed by XPS results.
... The Cr-Al-N, Cr-Si-N, and Cr-Al-Si-N have been successfully developed and the result shows the improvement of hardness level reduction with respect to friction coefficient [3]. Furthermore, previous study of Cr-Al-N, TiC-C, and Cr-B-N coating also confirmed that the coating composition successfully improve the hardness and wear resistance of the substrate [4]. The mechanical alloying process is a method for producing composite metal powders. ...
Cr-Al-BN powder was successfully applied as a coating agent on low carbon steel substrate by mechanical alloying method. The addition of BN as a doping material is considered as a feasible option because of excellent thermal and chemical stability presented by BN. In this paper, the compositions of Cr-Al-BN are varied Cr49.5-Al49.5-BN, Cr48.5-Al48.5-BN3, and Cr47.5-Al47.5-BN5. Each powder was milled by shaker mill for 2h in a stainless steel chamber with stainless steel balls to powder ratio 10:1. Subsequently, each powder compositions were mechanically alloyed onto substrate surface in air for 2h. The 2h heat treatment at temperature 800°C was conducted to each coated sample in vacuum furnace. In order to achieve the characteristics of phase composition and microstructure of the coating before and after heat treatment, XRD and Optical Microscope were performed, while the automatic microhardness tester was carried out to get the hardness of coating layer. The oxidation behaviour of coated substrates was also studied by heating treatment at 800°C for 8 cycles where each cycle is 20 h. The results show that the ball milling induces the formation of homogeneous Cr-Al-BN coating structure with a thickness of about 62.5 μm The optimum coating hardness and oxidation resistance was achieved by Cr47.5-Al47.5-BN5 coating composition. The addition of higher concentration ofBN increases the tendency onthe formation of intermediate phase of Cr2B and Cr2N. The detailed result of this study is shown in this paper.
... Thus, the carbon element perturbs the normal crystal arrangement of chromium nitrides. In addition, they transform into chromium carbonitride by the appearance of (111) and (131) Cr 3 N 0.6 C 0.4 at 41.02°and 51.20°, respectively (cubic structure, JCPDS 01 0892540) [25][26][27][28]. This agrees well with earlier works, where carbides and carbonitrides have been successfully formed from transition-metal-nitride-based thin films deposited on high carbon steel [17,21]. ...
... This gives additional evidence to support the bonding of N to Cr after annealing treatment at 900°C and it is maybe due to the higher electronegativity of nitrogen [25]. These results mean that CrN and Cr 2 N coexist in the sample as shown from the XRD analysis (Fig. 4) [26,27]. As shown in Fig. 6.c, the C1s peak, can be fitted into two peaks, which centre on 282.98 eV and 284.34 eV corresponding to C-Cr and sp 2 C-C, respectively presenting the Cr 7 C 3 and free carbon [25,28]. ...
Chromium nitrides were deposited by RF reactive magnetron sputtering from a Cr target on high carbon steel substrates XC100 (1.17 wt% carbon) in a N2 and Ar gas mixture. In order to investigate the formation of chromium nitrides, carbide and carbonitride compounds were subjected to vacuum annealing treatment for 1 h at various temperatures ranging from 700 to 1000 °C. The samples were characterized by EDS, XPS, XRD, SEM, nanoindentation and tribometry. The results showed the emergence of Cr2N and CrN during the early stages of annealing and the appearance of chromium carbonitride phases only at 900 °C. The (111) preferred orientation of the fcc CrN phase was changed to (002) at 900 °C in parallel with the appearance of chromium carbides. Nanoindentation tests revealed a gradual increase of the Young's modulus from 198 to 264 GPa when increasing the annealing temperature, while the hardness showed a maximum value (H = 22.4 GPa) at 900 °C. The low friction coefficient of the CrCN coating against a 100Cr6 ball was approximately 0.42 at 900 °C. The enhancement of mechanical and tribological properties was attributed to the stronger bonding CrC at the CrN/XC100 interfaces as confirmed by XPS results.
... It was reported that, after N incorporation, the fracture toughness of CrB 2 coatings was improved from 1.1 to 1.9 MPaÁ ffiffiffiffi ffi m p [25] while the transverse cracking on CrB 2 coatings disappeared [26]. Meantime, the wear rate of CrB 2 coatings (3.0 Â 10 À6 mm 3 /Nm) decreased to 2.4 Â 10 À6 mm 3 /Nm [27] and 0.6 Â 10 À6 mm 3 [28], respectively. The above results indicate that N incorporation is an effective way of improving the fracture toughness as well as tribological properties of CrB 2 coatings. ...
CrBC and CrBCN coatings with low and high B contents were deposited on 316L steel and Si wafers using an unbalanced magnetron sputtering system. Mechanical properties including hardness (H), elastic modulus (E) and fracture toughness (KIc) as well as residual stresses (σ) were quantified. A clear correlation between structural, mechanical and tribological properties of coatings was found. In particular, structural analyses indicated that N incorporation in CrBC coatings with high B content caused a significant structural evolution of the nanocomposite structure (crystalline grains embedded into an amorphous matrix) from nc-CrB2/(a-CrBx, a-BCx) to nc-CrN/(a-BCx, a-BN). As a result, the hardness of CrBC coating with high B content decreased from 23.4 to 16.3 GPa but the fracture toughness was enhanced. Consequently, less cracks initiated on CrBCN coatings during tribological tests, which combined with the shielding effect of a-BN on wear debris, led to a low friction coefficient and wear rate.
