AlCrSiN Coatings Research Articles

Effect of bias voltages and interlayer design on microstructure, mechanical properties, and adhesion performance of AlCrSiN coatings deposited using HiPIMS

This study fabricated AlCrSiN coatings from six alloy targets (Four Al7Cr3 targets and two Cr9Si1 targets) using high-power impulse magnetron sputtering (HiPIMS) with a focus on the effects of substrate bias voltage (−30 to −90 V) on deposition rate, microstructure, crystal orientation, residual stress, and mechanical properties. Electron Probe Microanalysis (EPMA) and X-ray Diffraction (XRD) results revealed that variations in bias voltage had little impact on the element composition or crystal structure (FCC) of AlCrSiN coatings; however, under high bias voltage (exceeding −60 V), the preferred orientation shifted from the (111) plane to the (220). Increasing the bias voltage from −30 to −90 V was shown to reduce the deposition rate (from 42.2 to 37.6 nm/min) and the thickness of the AlCrSiN coating (from 2.9 to 2.6 μm). It was also shown to increase the hardness (from 2147 to 3658 HV) and residual stress (from −0.01 to −0.59 GPa) by reducing the grain size and allowing the formation of a denser structure. Various interlayer designs (AlCr/AlCrxNy/AlCrN, CrSi/AlCrxNy/AlCrN, AlCr/CrSixNy/CrSiN, CrSi/CrSixNy/CrSiN) were assessed in terms of adhesion strength between the AlCrSiN and substrate. Under the same AlCrSiN deposition condition, with the bias voltage set to −60 V, the highest adhesion strength (from 32.28 to 45.81 N) was achieved using a CrSi/CrSixNy/CrSiN interlayer structure.

Comparative tribological performance of a-C:H, ta-C and AlCrSiN coatings on 20CrMnTi gear steel under dry sliding condition

PurposeThis study aims to investigate the surface modification on 20CrMnTi gear steel individually treated by diamond-like carbon films and nitride coatings.Design/methodology/approachFor this purpose, the mechanical properties of a-C:H, ta-C and AlCrSiN coatings are characterized by nano-indentation and scratch tests. The friction and wear behaviors of these three coatings are evaluated by ball-on-disc tribological experiments under dry contact conditions.FindingsThe results show that the a-C:H coating has the highest coating-substrate adhesion strength (495 mN) and the smoothest surface (Ra is about 0.045 µm) compared with the other two coatings. The AlCrSiN coating shows the highest mean coefficient of friction (COF), whereas the ta-C coating exhibits the lowest one (steady at about 0.16). The carbon-based coatings possess excellent self-lubricating properties compared with nitride ceramic ones, which effectively reduce the COF by about 64%. The major failure mode of carbon-based coatings in dry contact is slight abrasive wear. The damage of AlCrSiN coating is mainly adhesive wear and abrasive wear.Originality/valueIt is suggested that the carbon-based film can effectively improve the friction-reducing and wear resistance performance of the gear steel surface, which has a promising application prospect in the mechanical transmission field.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2023-0129/

Structure and Properties of Arc Ion Plating Deposited AlCrSiN Coatings Controlled by Pulsed Bias Voltage

AlCrSiN coatings are promising protective candidates for cutting and forming tools. During the coating deposition process, the microstructure and properties of the coatings were dramatically affected by bias voltages. To further optimize and enhance the AlCrSiN coating, a series of coatings were deposited at different pulse bias voltages using arc ion plating technology. By virtue of scanning electron microscopy, X-ray diffraction, scratch method, OCP, EIS, and other analytical methods, the effects of the pulse bias voltage on the crystal structure, microstructure, and mechanical, tribological, and electrochemical properties of the AlCrSiN coatings were analyzed. The study revealed that the pulse bias voltage exerted a slight influence on the aluminum and nitrogen content of the coatings. As the pulse bias voltage increased, the hardness, critical load, and tribological performance of the AlCrSiN coatings first increased gradually, and then were impaired slightly. When the pulse bias voltage was −100 V, the resulting AlCrSiN coating exhibited the densest structure, the highest hardness, the strongest adhesion, and the best wear resistance. In this case, the coating hardness and critical load reached 2668 HV and 72.7 N, respectively. The friction coefficient and wear rate were 0.35 and 1.02 × 10−3 μm3/N·μm, respectively. Simultaneously, the AlCrSiN coating demonstrated exceptional corrosion resistance in 3.5 wt.% NaCl solutions, surpassing uncoated 304 steel by 3~4 times.

Comparative Study of Mechanical Performance of AlCrSiN Coating Deposited on WC-Co and cBN Hard Substrates

The objective of this study is to explore and compare the mechanical response of AlCrSiN coatings deposited on two different substrates, namely, WC-Co and cBN. Nano-indentation was used to measure the hardness and elastic modulus of the coatings, and micro-indentation was used for observing the contact damage under Hertzian contact with monotonic and cyclic (fatigue) loads. Microscratch and contact damage tests were also used to evaluate the strength of adhesion between the AlCrSiN coatings and the two substrates under progressive and constant loads, respectively. The surface damages induced via different mechanical tests were observed using scanning electron microscopy (SEM). A focused ion beam (FIB) was used to produce a cross-section of the coating–substrate system in order to further detect the mode and extent of failure that was induced. The results show that the AlCrSiN coating deposited on the WC-Co substrate performed better in regard to adhesion strength and contact damage response than the same coating deposited on the cBN substrate; this is attributed to the lower plasticity of the cBN substrate as well as its less powerful adhesion to the coating.

Improved adhesion of cathodic arc PVD AlCrSiN coating on ion-implanted WC-Co substrates

Ion implantation has been shown to improve adhesion strength of AlCrSiN coatings due to a synergic enhancement on fracture toughness and load bearing capability of the substrate that can potentially increase the in-service efficiency of coated cutting tools. In this work, AlCrSiN coatings deposited by PVD on WC-Co substrates implanted with Ti, Cr and N ion species have been processed. The mechanical properties and adhesion have been characterized by contact techniques and the residual stress of the coatings and substrates have been evaluated using FIB-DIC technique and Vickers indentation tests, respectively. An improvement of adhesion strength is obtained for treated substrates, especially for those implanted with titanium and chromium ions. This improvement is attributed to the introduction of residual stresses in the substrate, which increases its fracture toughness and enhances its load bearing capability.

Mechanical Performance of AlCrSiN and AlTiSiN Coatings on Inconel and Steel Substrates after Thermal Treatments

The objective of this study was to explore the mechanical properties of AlCrSiN and AlTiSiN coatings deposited on Inconel and steel substrates after thermal treatments of 500 °C and 800 °C. Nanoindentation was used to measure the hardness and elastic modulus of the coatings, and microindentation was used for observing the contact damage with Hertzian contact loadings. Microscratch and Mercedes tests were used to evaluate the adhesive strength between coating and substrate with both progressive and static loads, respectively. The surface damage was inspected by optical microscopy and scanning electron microscopy (SEM). Focus ion beams (FIB) were used to mill the cross-sections in order to detect the extent and mode of failure. The results show that AlCrSiN coatings and Inconel substrates exhibit better mechanical performance, even after thermal treatments.

Influence of the Addition of the Elements Ti and Cr on the Structure, and Mechanical and Tribological Properties of AlSiN Coatings

The influence of Al/Ti and Al/Cr ratios on the structural, mechanical and tribological properties of AlTiSiN and AlCrSiN coatings, deposited by the cathodic arc evaporation PVD method at a temperature of 400°C, was investigated. The remains of the original AlSiN hexagonal phase were observed in the obtained coatings as well as the crystallites of cubic TiN and CrN, respectively. XPS analysis assumes the presence of a substoichiometric SiN. The addition of 11 at.% Ti or 13 at.% Cr in AlSiN led to an increase in both the coating’s resistance to plastic deformation and the plasticity index. The addition of 13 at.% and 24 at.% Cr to the AlSiN coating structure resulted in a decrease in the average coefficient of friction with 18% and 36% against a counterpart of Al2O3, respectively, and with 36% for both concentration against steel ball counterpart. The addition of Ti have no influence on the values of the coefficient of friction at using ceramic counterpart, while at steel counterpart decreased it up to 30%. Both element change the abrasion effect of the coating.Keywords:AlCrSiN; AlTiSiN;Cathodic Arc Deposition; Tribological Behaviour; Abrasion Resistance; Nanoindentation

Thermostability, oxidation, and high-temperature tribological properties of nano-multilayered AlCrSiN/VN coatings

In this study, monolithic AlCrSiN, VN, and nano-multilayered AlCrSiN/VN coatings were deposited using a hybrid deposition system combining arc ion plating and pulsed direct current magnetron sputtering. The microstructure, thermostability, mechanical, oxidation and tribological properties of the coatings were comparably investigated. The multilayered AlCrSiN/VN coating exhibited a face-centered cubic (fcc) structure with (200) preferred orientation and showed the highest hardness (30.7 ± 0.5 GPa) among these three coatings due to the multilayer interface enhancement mechanism and higher compressive stress. The AlCrSiN sublayers effectively prevented the V element from rapid outward diffusion to the surface of AlCrSiN/VN coating at elevated temperatures, which improved the oxidation resistance of the coating. Decomposition of V (Cr)–N bonds occurred at annealing temperatures from 800 °C to 1000 °C and V2N phase appeared at 1100 °C. The AlCrSiN/VN coating showed excellent tribological performance at high temperatures by combining the merits of VN layers for low friction coefficient and AlCrSiN layers for superior oxidation resistance. Compared to VN and AlCrSiN coatings, AlCrSiN/VN coating showed the lowest wear rate of 2.6×10-15 m3/N·m at 600 °C and lowest friction coefficient of 0.26 at 800 °C with a relativity low wear rate of 39.4×10-15 m3/N·m.

Influence of V addition on the microstructure, mechanical, oxidation and tribological properties of AlCrSiN coatings

The precise control of composition and out-diffusion/oxidation behavior of V element is the principal factor for V-containing coatings with superior mechanical and anti-wear properties at elevated temperatures. In this study, nanocomposite AlCrVSiN coatings were deposited by a hybrid deposition technique combining arc ion plating and pulsed DC magnetron sputtering. The influence of V content on the microstructure, mechanical, high-temperature tribological and oxidation properties of AlCrVSiN coatings was systematically investigated. The results showed that all the AlCrVSiN coatings exhibited a fcc-Cr(Al,V)N solid solution phase. With the increase of V content, the coating deposition rate increased from 14.0 to 25.2 nm/min, and the hardness of coatings firstly increased from 28.0 to 34.6 GPa and then decreased to 28.8 GPa. The incorporation of V into AlCrSiN coatings promoted the formation of lubricative oxides (e.g. V2O5), contributing a sharp decrease in friction coefficient of the AlCrSiN coatings from 1.0 to 0.56 and from 0.86 to 0.21 at 600 °C and 800 °C, respectively. The Al0.38Cr0.40V0.17Si0.05N and Al0.31Cr0.33V0.32Si0.04N coatings exhibited the best anti-wear property at 600 °C and 800 °C, respectively, determined by comprehensive influences of mechanical property, oxidation resistance and formation of lubricant tribofilm.

Effect of Silicon Concentration on the Properties of Al-Cr-Si-N Coatings Deposited Using Cathodic Arc Evaporation.

The current market requirements are related to the introduction of new protective coatings for tools and machine parts with much better performance properties. These requirements are met by the AlCrSiN coatings; however, knowledge on the adhesion of these coatings to the substrate, as well as on their corrosion resistance, is deficient. The article presents the results of technological works on the coating deposition from AlCrSi cathodes with a silicon concentration from 0 at% to 10 at% by the cathodic arc evaporation and the results of systematic studies of their structure, mechanical, tribological and electrochemical properties. A correlation between the above-mentioned properties and the silicon concentration in the AlCrSiN coatings has been found and discussed. The coatings formed from cathodes containing less than 5 at% Si crystallize in the cubic structure. The size of the crystallites decreases with the silicon concentration increase. The coatings are characterized by a high hardness with a maximum of about 37 GPa (2 at% Si). The adhesion of the coatings is almost independent of the concentration of silicon. The wear rate is about one order of magnitude higher for coatings deposited from cathodes with a silicon concentration of 5 at% and 10 at% compared to a coating with a lower silicon concentration. This finding is consistent with the results of corrosion resistance studies. The coating deposited from the cathode with 10 at% of silicon exhibits the best anticorrosion properties against the salt solution.

High-temperature oxidation behaviour of AlTiSiN and AlCrSiN coatings

ABSTRACTThis study was aimed to explore the high-temperature oxidation behaviour of AlTiSiN and AlCrSiN coatings. The coatings were deposited using arc ion plating and annealed in air at a temperature range of 600–1000°C for 2 h. The results showed that the oxidation of AlTiSiN coatings started at 900°C and failed at 1000°C. However, the oxidation of AlCrSiN was different from AlTiSiN coatings, which commenced at 800°C and kept stable till 1000°C. The hardness of the as-deposited AlTiSiN coatings dropped from 25.2 to 16.5 GPa after 1000°C annealing, while AlCrSiN coatings decreased from 24.2 to 20.5 GPa. The AlCrSiN coating exhibits a better high-temperature oxidation resistance than AlTiSiN coating.

Structure and property optimization of Ni-containing AlCrSiN coatings by nano-multilayer construction

AlCrSiN coatings with exceptional oxidation resistance are promising protective layers for cutting tools. Due to the inferior tribological properties at elevated temperatures, recently, tailoring of AlCrSiN by alloying has attracted widespread attention. The addition of Ni is a practical method to reduce friction and increase toughness. Whereas, the lower hardness of Ni-containing AlCrSiN coatings leads to poor wear resistance. Here, to optimize the phase structure of monolithic AlCrSiN–Ni for synergistic improvement of mechanical and tribological properties, the AlCrSiN–Ni/AlCrN multilayer was deposited by cathodic arc evaporation and investigated by combing X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, nanoindentation, and ball-on-disc tribometer. Without the formation of wurtzite AlN, epitaxially grown AlCrSiN–Ni/AlCrN coatings obtain coherent interlayer interfaces and dual-phase cubic structure involving nitride and metallic Ni. Correspondingly, the hardness increases from 21.6 ± 0.8 GPa of AlCrSiN–Ni to 31.1 ± 0.7 GPa of AlCrSiN–Ni/AlCrN. Also, significant enhancement of scratch toughness was achieved by the multilayer. For wear tests at 600 °C, the multilayer exhibits an average friction coefficient of ∼0.81, which is between ∼0.95 of AlCrSiN and ∼0.61 of AlCrSiN–Ni. Furthermore, the superior mechanical properties upgrade the wear resistance of the coating. The wear rate at 600 °C for the multilayer is 3.9 × 10−6 mm3/N·m, while other monolithic coatings have a wear rate higher than 2.0 × 10−5 mm3/N·m.

Comparison of the Structure of AlCrSiN Coating Produced by Planar and Rotating Arc Technology

The aim of this work was an attempt to verify two concepts of cathode modules, and the qualification of structure analysis of nitride coatings with the addition of silicon. The analysis covered one of the most commonly used in industrial conditions AlCrSiN coatings manufactured by the planar ARC and rotating (LARC®) technology, which have recently gained more and more recognition in the production of coatings by physical vapour deposition (PVD) technique. Their microstructure was examined using transmission electron microscope (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Their mechanical and tribological properties were compared in terms of their application in the field of surface engineering. Tribological tests were performed in sliding friction conditions using the ball-on-disc method, where a ceramic Al2O3 ball was used as the counterpart. Presented research results allow to determine the relationship between the structure, wear resistance, and the specific module responsible for the number, type and position of cathodes used in the constitution of the tested coatings. This study complements and contributes to the knowledge on the direct influence of the chemical composition of the coating and the method of its production on the quality and structure of the coated element for wear-resistant coatings produced by PVD in the arc evaporation method (AE).

Effect of Plasma Nitriding Pretreatment on the Mechanical Properties of AlCrSiN-Coated Tool Steels.

Surface modification of steel has been reported to improve hardness and other mechanical properties, such as increase in resistance, for reducing plastic deformation, fatigue, and wear. Duplex surface treatment, such as a combination of plasma nitriding and physical vapor deposition, achieves superior mechanical properties and resistance to wear. In this study, the plasma nitriding process was conducted prior to the deposition of hard coatings on the SKH9 substrate. This process was done by a proper mixture of nitrogen/hydrogen gas at suitable duty cycle, pressure, and voltage with proper temperature. Later on, the deposition of gradient AlCrSiN coatings synthesized by a cathodic-arc deposition process was performed. During the deposition of AlCrSiN, CrN, AlCrN/CrN, and AlCrSiN/AlCrN were deposited as gradient interlayers to improve adhesion between the coatings and nitrided steels. A repetitive impact test (200k–400k times) was performed at room temperature and at high temperature (~500 °C) to assess impact resistance. The results showed that the tribological impact resistance for the synthesized AlCrSiN increased because of a progressive hardness support. The combination of plasma nitriding and AlCrSiN hard coatings is capable of increasing the life of molding dies and metal forging dies in mass production.

Influence of Ni-addition on mechanical, tribological properties and oxidation resistance of AlCrSiN coatings

AlCrSiN coatings with splendid mechanical and thermal properties have attracted wide attention as excellent alternatives for advanced machining applications. Here, Ni-alloyed AlCrSiN coatings were deposited by cathodic arc evaporation and elaborated with respect to mechanical, tribological and anti-oxidation properties. With the increase of Ni content, multiphase composite structured AlCrSiN-Ni coatings show a sustained decline in hardness, elastic modulus and the ratio of hardness to modulus, which causes the decrease of wear resistance at room temperature and 600 °C. Nevertheless, the addition of Ni effectively enhances the toughness and reduces the friction, especially, at 600 °C, where AlCrSiN, AlCrSiN_Ni5, and AlCrSiN_Ni20 obtained a average friction coefficient of ~0.93, 0.86 and 0.66, respectively. Oxidation kinetics studies at 800 – 1000 °C indicate that Ni-containing coatings have relatively lower activation energies, 173.8 kJ/mol of AlCrSiN_Ni5 and 156.6 kJ/mol of AlCrSiN_Ni20, than 176.5 kJ/mol of AlCrSiN. The faster outward diffusion of Cr in Ni-containing coatings forms a Cr2O3/NiAl2O4 two-layer oxide scale with less protection effect and poor adhesion, leading to inferior oxidation resistance.

Influence of N2/Ar Flow Ratio on Microstructure and Properties of the AlCrSiN Coatings Deposited by High-Power Impulse Magnetron Sputtering

The cutting properties of tools can be greatly improved by AlCrSiN coatings. The AlCrSiN coatings with nitrogen content in the range of 28.2–56.3 at.% were prepared by varying the N2/Ar flow ratio from 1/4 to 1/1. The influence of N2/Ar flow ratio on composition, microstructure, and mechanical properties, as well as the tribological properties, of the coatings was investigated. With increasing N content, the coating microstructure gradually evolved from single fcc-(Cr,Al)N (200) phase to the mixture of fcc-(Cr,Al)N and hcp-(Cr,Al)N phase, which corresponds to an increased crystallinity within the coatings. The coating presents the highest hardness and best wear resistance for an N2/Ar flow ratio of 1/1, but the film adhesive strength and inner stress decreased obviously with increasing N2/Ar flow ratio, which was attributed to the rapid reduction of particle kinetic energy induced by the obstruction of neutral nitride particles between target and substrates. The highest H3/E*2 value exhibited the lowest wear rate, at 0.81 × 10−14 m3/(N·m), indicating that it had the best resistance to plastic deformation. The main wear mechanisms of the as-deposited coatings were abrasive wear and adhesive wear. The increasing crystallinity of the interior coatings resulted in higher hardness and better tribological behavior with an increase in N2/Ar flow ratio.

Improving the Tribological and Mechanical Properties of an Aluminium Alloy by Deposition of AlSiN and AlCrSiN Coatings

This paper presents an improvement to the mechanical and tribological properties of aluminium alloys. AlSiN and AlCrSiN coatings (with different Cr content) were deposited on substrates of Al-Cu-Mg alloy by the cathodic arc evaporation method at 400°C. Surface morphology and chemical composition were estimated by a scanning electron microscope equipped with an energy dispersive spectrometer and mechanical profilometer. The increasing chromium content in the coating led to an increase in the coating hardness. The tribological behaviour of the coated and uncoated Al-Cu-Mg alloy samples was examined using the Ball-on-Disk method (ASTM G99-95) at a load of 10N using Al2O3 ball as a counterpart.

Effect of Substrate Bias and Coating Thickness on the Properties of nc-AlCrN/a-Si<sub>x</sub>N<sub>y</sub> Hard Coating and Determination of Cutting Parameters

Nitride hard coatings Al25.5Cr21Si3.5N were deposited on WC-Co substrates with a different thickness and a negative substrate bias voltage by the LAteral Rotating Cathodes Arc technology. The nanoindentation tests were performed for analysis of AlCrSiN coatings in order to determine the most promising combination of parameters for subsequent machining. On the basis of results of nanohardness measurement and Ratio H/E*, which represents the resistance to plastic deformation and cracking, deposition conditions were selected for coating of turning cemented carbide inserts. For the evaluation of coating adhesion to substrate, Mercedes adhesion test was used. Chip forming tests and long-term tool life tests were performed for determination of cutting parameters (cutting speed, feed rate and depth of cut) for AlCrSiN coated cemented carbide inserts when machining austenitic stainless steel material.

Investigations on microstructure and mechanical properties of containing-Si coatings

ABSTRACTAdvanced AlCrSiN and AlTiSiN coatings were deposited on high-speed steel by cathodic vacuum arc. The microstructures, mechanical and tribological properties were studied, as well as cutting performance. The results show that multilayered AlCrSiN coating mainly consists of nanocrystalline fcc-AlCrN and a few amorphous Si3N4 phases, with an average module period of about 6.0 nm. While the AlTiSiN coating reveals nano-composite structure consisted of nanocrystalline fcc-AlTiN and hcp-AlN embedded into Si3N4 amorphous matrix. The AlCrSiN-coated tool reveals a more excellent cutting performance when compared with the AlTiSiN-coated tool due to its higher hardness, adhesion strength, H3/E*2 ratio and wear resistance when compared with the AlTiSiN coating.

Pre-, intermediate, and post-treatment of hard coatings to improve their performance for forming and cutting tools

Abstract Three coating systems, including single-layer AlCrSiN coatings, two-layer CrSiBN/CrN coatings, and single-layer TiAlN coatings were deposited using an arc evaporation system. The effects of various pre-, intermediate, and post-treatments on the properties and performance of the coatings were studied. The tribological properties of the AlCrSiN and TiAlN coatings were evaluated using ball-on-disc tests. The wear behavior of the AlCrSiN coatings was affected by coating morphology. The wear volume of the counter surface increased with the surface roughness of the coating. Furthermore, material transfer and build up to the coating surface were higher for the surfaces treated by grinding and shot blasting than those treated by other methods. The erosion and corrosion properties of the CrSiBN/CrN coatings were evaluated in molten aluminum and sulfuric acid, respectively. Intermediate treatment of the CrSiBN/CrN coatings improved their erosion and corrosion resistance by preventing formation of localized erosion and corrosion. Post-treatment of the TiAlN coatings decreased the amount of material transfer and wear volume of the counter surface. Meanwhile, drilling tests of the TiAlN coatings showed that post-treatment of the coatings improved the drilling regularity and stabilized the spindle torque, which helped to improve tool wear and cutting performance. Based on these results, mechanical surface pre-treatment by processes like micro-blasting, polishing, and buffing, along with plasma nitriding can improve the tribological properties and adhesion of coating systems. Likewise, intermediate and post-treatment of coating surfaces improve erosion and corrosion resistance and cutting performance. In conclusion, the studied treatment processes gave coatings with good performance that are possible candidates for forming and cutting tools.