TiAlSiN Coatings Research Articles

Sustainable Hard Machining of AISI 304 Stainless Steel Through TiAlN, AlTiN, and TiAlSiN Coating and Multi-Criteria Decision Making Using Grey Fuzzy Coupled Taguchi Method

Sustainable Hard Machining of AISI 304 Stainless Steel Through TiAlN, AlTiN, and TiAlSiN Coating and Multi-Criteria Decision Making Using Grey Fuzzy Coupled Taguchi Method

TiAlSiN(Ag) coatings for high temperature applications: The influence of Ag alloying on the morphology, structure, thermal stability and oxidation resistance

The influence of Ag content on the morphology, structure, hardness (H) and reduced Young's modulus (E), thermal stability, and oxidation resistance of TiAlSiN(Ag) coatings is investigated. The coatings were produced by DC reactive magnetron sputtering, with increasing Ag contents from 0 up to 15.9 at.%. All coatings exhibit a fcc type structure. The coating with 1.5 at.% Ag content displays the highest H and E values as a result of the coating densification and the grain refinement caused by the co-deposition of immiscible phases. Further Ag concentration degrades the H and E values of the coatings due to the incorporation of a softer Ag phase in the structure. Annealing at 800 °C in protective atmosphere for 2 h enhances the coatings crystallinity, with small increments in the H and E values. The dynamic thermal gravimetric oxidation curves reveal that Ag additions do not affect the starting point of oxidation of the coatings (~990 °C). However, it enhances their oxidation resistance. The improved oxidation resistance of the coatings with Ag incorporation is caused by the diffusion of Ag through the oxide scale to the surface, which modifies the composition of the Ti-Al-O layer, producing a more protective Al rich layer.

Tribological performance of the gradient composite TiAlSiN coating with various friction pairs

The gradient composite TiAlSiN coatings were prepared by the cathodic arc ion technology. The tribological properties of TiAlSiN coating were investigated by the ball on disc tribological test in the humid atmosphere against various friction pairs. The results show that the TiAlSiN coating exhibited excellent mechanical properties. The corresponding wear mechanism varied with different friction pair under loads (2 N, 15 N, 25 N). The wear mechanisms of the coatings against stainless steel ball and ZrO 2 ball were the adhesive wear and the abrasive wear, respectively. The wear rate and the friction coefficient of coating against Si 3 N 4 ball were significantly decreased due to the generation of SiO 2 •nH 2 O layer. However, the SiO 2 •nH 2 O layer was weakened with the increasing of the load. Results show that the tribological properties of TiAlSiN coating are affected by the material of friction pairs. Lubrication film can be formed in a humid environment to improve the tribological properties of the coating. • The soft SUS friction pair transferred to the surface of TiAlSiN coating. • The stable SiO 2 . nH 2 O lubrication film required certain Si content, appropriate contact stress and temperature.

Surface textures fabricated by laser and ultrasonic rolling for improving tribological properties of TiAlSiN coatings

To enhance the tribological properties of the TiAlSiN coatings, two types of micro-textures were fabricated on the AISI 1045 steel substrates by laser texturing and ultrasonic rolling texturing prior to coating deposition. The mechanical properties and tribological behaviors of different samples were evaluated. Results revealed that the micro-textures improved the tribological properties of TiAlSiN coatings under dry friction and lubricant conditions. Under dry friction conditions, the friction coefficient and steel ball wear rate of the coatings decreased by ~16.9% and ~44.2%, respectively, after ultrasonic rolling texturing pretreatment, when compared with the coatings deposited on the polished substrates. Under lubricant conditions, the two values were reduced by ~27.8% and ~73.4%, respectively. The contribution of micro-textures was primarily to amplify lubrication, trap wear debris, decrease contact area and improve bearing capacity. The modification mechanism of the ultrasonic rolling texturing also benefited from the enhanced mechanical properties.

Structure and Mechanical Properties of PVD and CVD TiAlSiN Coatings Deposited on Cemented Carbide

This work reports the results of our investigation of the structure and mechanical properties of physical vapor deposition (PVD) and chemical vapor deposition (CVD) TiAlSiN coatings deposited on cemented carbide substrates. For the first time, a novel nanocomposite of Ti0.13Al0.85Si0.02N coating deposited from TiCl4-AlCl3-SiCl4-NH3-H2 gas precursors was prepared by low pressure chemical vapor deposition (LPCVD) at 780 °C and a pressure of 60 mbar, while PVD Ti0.31Al0.60Si0.09N coating was prepared using the arc ion plating method. The investigation results including morphology, microstructure, chemical composition, phase component, and hardness were carried out by scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), and nano-indentator. TEM results revealed that both PVD and CVD TiAlSiN coatings consisted of nanocrystalline embedded in SiNx amorphous. The nanohardness of CVD Ti0.13Al0.85Si0.02N coating obtained in this work was 31.7 ± 1.4 GPa, which was 35% higher than that of the PVD Ti0.31Al0.60Si0.09N coating.

Improvement of the Physical and Mechanical Properties of the Cutting Tool by Applying Wear-resistant Coatings Based on Ti, Al, Si, and N

From the great variety of methods to improve the efficiency of cutting tools, it is necessary to highlight the methods of applying wear-resistant coatings, which in recent years are increasingly used. Applying wear-resistant coatings on the cutting tool can significantly increase its efficiency and intensify machining modes. Mechanisms of strengthening the wear-resistant coating for materials have been analyzed under the impact of technological parameters of coating condensation process on its structure parameters and mechanical properties, formation of single and multi-element coatings based on titanium nitrides, aluminum, and silicon, the transformation of coating properties by obtaining complex coatings, and principles formation of complex coatings designed for different cutting tools. The influence of the coating on the mechanical properties of high-speed steel is shown. In the magnetron sputtering coatings on P6M5 steel samples, the microhardness of the coatings is TiN – 20–24 GPa, AlN – up to 16 GPa, TiAlN – up to 35 GPa, AlTiN – up to 32 GPa, TiAlSiN – 32–37 GPa, including while the microhardness of the substrate of steel P6M5 – 6–9 GPa. The microhardness of TiAlN and TiAlSiN coatings applied on an instrumental basis is 1,5 – 1,9 times higher than the microhardness of TiN, AlN coatings. It was found that the wear intensity of P6M5 steel without coating is 6 times higher than with AlTiN, TiAlN, and TiAlSiN coating, 3 times higher than with TiN and AlN coating. The coated tool is characterized by increased reliability and higher stability and allows the processing process with higher cutting modes.

Influence of annealing temperature on microstructure evolution of TiAlSiN coating and its tribological behavior against Ti6Al4V alloys

TiAlSiN multicomponent coating, owing to its high hardness and excellent high temperature resistance, was widely used in the cutting field of difficult-to-cut materials such as titanium alloys. For machining titanium alloys, high temperature is easy to gather on the tool chips and deteriorate the cutting tools. Moreover, high temperature will also promote the microstructure evolution and make the wear mechanism more complex. In this paper, TiAlSiN coatings were deposited on cemented carbides and annealed at 400 °C, 600 °C and 800 °C respectively for 60 min in air, followed by reciprocating friction tests against Ti6Al4V counterparts. AFM, SEM, EDS and XPS were applied to investigate the microstructure evolution and tribological behavior of TiAlSiN coating after high temperature annealing. The results demonstrated that the oxidation resistance of TiN phase in TiAlSiN coating was worse than Si3N4 and AlN phases. These nitrides can be oxidized to TiO2, SiOx and AlOx under 600 °C, and the depth of oxide layer was increased with the rising annealing temperature, resulting in the coarsened microstructure. The wear mechanisms of as-deposited TiAlSiN coating were oxidation wear and adhesion wear. With the rising annealing temperature, abrasive wear was gradually enhanced. For the TiAlSiN coating annealed at 800 °C, abrasive wear became the dominant wear mechanism.

The modulation of the TiAlSiN coating on the band gap of monolayer MoS2

ABSTRACT MoS2 is a two-dimensional semiconductor nanoelectronic device, the application value and application field of which can be increased based on band-gap modulation. In this study, monolayer MoS2 samples were prepared on four TiAlSiN-coated substrates with different Ti compositions using the mechanical stripping approach. The band-gap variation in monolayer MoS2 was studied using the photoluminescence (PL) spectrum. The modulation in the electronic properties of monolayer MoS2 when the TiAlSiN coating was applied was obtained based on the first-principle calculations. Furthermore, contact models were obtained for three TiAlSiN coatings with different Ti compositions with respect to monolayer MoS2. The state densities of the three crystal structures as well as the differences between the charge density and the state of density at the contact surface were evaluated. After the analysis, the calculated results were observed to agree with the experimental results, presenting an explanation for the modulation mechanism.

Influence of Phase Composition in TiAlSiN Hard Coatings on the Evolution of Structure and Mechanical Properties

The aim of this study is to investigate the structural evolution and mechanical properties of TiAlSiN coatings when processed by the arc ion plating method. To form a hard coating, Ti, Al, and Si powders were mechanically alloyed by planetary ball milling; the powders were then densely compacted during a rapid sintering process into a ternary system coating, i.e. TiAlSi. The evolution of the structural phase from a powder to a compact material is dominated considerably by phase states such as a supersaturated solid solution or intermetallic compounds. In the case of coating layers, the factors that determine the structural evolution are associated with the phase stability of the nano-crystalline structure that in turn is associated with the Ti/Al composition ratio. Motivated by this, we performed experiments to investigate the distribution of microstructures; the material’s binding energy, quantitative properties, transformation of crystal structure, and distribution of amorphous/crystalline were all recorded. In particular, the relationship between the physical and chemical properties during the coating process is considered to be the dominant factor controlling the orientation and morphology of that zone (1, T, and 2). The TiAlSiN coating layer was found to have hardness above 45 GPa and an adhesion above 100 N. In other words, understanding the evolution and structure of TiAlSin helped us to produce a material with excellent properties that can be used as a hard coating. Specifically, these properties were induced by a grain refinement of the nano-crystalline structure that corresponds to an increase in the silicon nitride contents.

Effect of excitation coil voltage on TiAlSiN coating on 42CrMo steel surface

TiAlSiN coating was painted on the surface of 42CrMo steel by arc ion plating technology, and the influence of excitation coil voltage on the structure and friction property of the coating were analyzed. Results showed that there were a lot of holes on TiAlSiN coatings under different voltages. With the increase of voltage, the structure and friction property changed a lot: the roughness and thickness of the coating increased obviously and all layers were in a state of tight bond and formed a columnar structure; many voids appeared led to the decrease of coating density; the coating with higher microhardness was obtained, which was higher than that of alloy steel substrate; the friction coefficient and wear rate of the coating first decreased then increased, and the minimum wear rate occurred when the voltage reached 30 V, under condition of which the coating mainly suffered from abrasive wear, so more flat surface and denser structure of the coating formed, which significantly improved the wear resistance.

Characterisation and performance evaluation of TiSiN &TiAlSiN coatings by RF magnetron sputtering deposition during end milling of maraging steel

Monolayer nanostructured thin films of TiSiN & TiAlSiN were deposited on WC-Co milling inserts using RF magnetron sputtering for metal cutting. The alloy targets of TiSi (80/20 at%) & TiAlSi (34/56/10 at%) were used for the deposition in an Ar + N atmosphere. The deposition time and parameters are optimized to develop a uniform and homogenous coating. The mechanical and metallurgical properties are characterized to analyze the wear resistance of the coating. The machinability studies on MDN 250 maraging steel is carried out using TiSiN and TiAlSiN coated WC-Co inserts under dry and wet environment. The machining responses such as surface roughness, cutting force, tool wear and tool life are analyzed by varying spindle speed. The results showed that TiAlSiN coating had a higher wear resistance and machining performance compared to the TiSiN coating owing to the high hardness and plasticity index of the coating.

Influence of Al Content on Micro-Properties of TiAlSiN Coatings Deposited by Plasma Enhanced Magnetron Sputtering

TiN coating has attracted substantial attention due to its high hardness and good wear resistance. To meet the current more demanding service environment, Al and Si were added to TiN coating to further improve its comprehensive performance in this work. TiAlSiN coatings with different Al content governed by Al target power were prepared on GH169 superalloy by plasma enhanced magnetron sputtering, and the Al content effects on microstructure and mechanical properties of the coatings were explored in detail. The crystal structure, chemical composition, micromorphology and surface roughness of the coatings were analyzed by XRD, SEM, EDS and AFM, respectively. The mechanical properties of the coatings at room temperature including micro-hardness, elastic modulus and bonding strength were evaluated by nano-indentation and nano-scratch, respectively. With the increase of Al target power, Al content in coatings increased, and the preferred orientation of TiN(111) plane was also more and more obvious. At the same time, the surface morphology of the coatings changed from the round cell shape to the hexagonal star shape. The hardness, elastic modulus and adhesion of the coatings increased first and then decreased with the Al content. The TiAlSiN coating with Al content of 19.25% possesses the best comprehensive properties.

Scratch response and tribological properties of TiAlSiN coatings deposited by reactive deep oscillation magnetron sputtering

TiAlSiN nanocomposite coatings were deposited using deep oscillation magnetron sputtering with various nitrogen flow ratio (fN2) of 0%–20%. The increase of fN2 promotes phase separation from a single crystallographic TiAlSi to nc-(Ti,Al)N/a-Si3N4 phase. The introduce of N content leads to the formation of refined grain size, smooth morphologies and dense microstructure. Ti0.15Al0.39Si0.07N0.39 coatings with (Al + Si)/Ti ratio of 2.9 deposited at fN2 = 10% reach the highest hardness of 32.8 GPa, H/E* of and 0.0837 and H3/E*2 of 0.23. The introduce of N leads to failure mode changing from brittle tensile cracking (through-thickness cracking) to buckle spallation (interfacial failure). Ti0.15Al0.39Si0.07N0.39 coatings with highest H, H/E* and H3/E*2 ratios show buckling failure with high LC1 of 25.4 N and LC3 of 43.6 N. Correspondingly, Ti0.15Al0.39Si0.07N0.39 coatings are subjected to oxidation wear with low coefficient of friction of 0.41 and specific wear rate of 0.39 × 10−6 mm3 N−1 m−1.

Elevated temperature micro-impact testing of TiAlSiN coatings produced by physical vapour deposition

A high temperature micro-impact test has been developed to assess the fracture resistance of hard coatings under repetitive dynamic high strain rate loading at elevated temperatures. The test was used to study the temperature dependence of the resistance to micro-scale impact fatigue of TiAlSiN coatings on cemented carbide at 25–600 °C. Nanoindentation and micro-scratch tests were also performed over the same temperature range. The results of the micro-impact tests were dependent on the impact load, coating microstructure, coating and substrate mechanical properties, and their temperature dependence. At higher temperatures there was a change in failure mechanism from fracture-dominated to plasticity-dominated behaviour under the cyclic loading conditions. This was attributed to coating and substrate softening.

Research on Friction Characteristics of AlCrN and TiAlSiN Coatings and Properties of Coated Tools

AlCrN and TiAlSiN coatings were deposited on the surface of 30CrMnSi steel and cemented carbide YT15 by multi-arc ion plating technique. A scanning electron microscopy was used to observe the surface morphologies of both coatings. The reciprocating sliding tests of AlCrN and TiAlSiN coating were performed to investigate the friction coefficients and the wear mechanisms of both coatings were analyzed as well. Dry machining tests on 30CrMnSi hardened steel were carried out with the AlCrN and TiAlSiN coated tools on a CA6140A lathe. The effects of cutting speed on cutting forces and cutting temperatures of AlCrN and TiAlSiN coated tools were obtained and analyzed. The microcosmic micrographs of wear areas of both coated tools were observed and investigated by scanning electron microscope and energy dispersive spectrum. The results show that the hardness and bonding strength of AlCrN coating are higher than that of TiAlSiN coating, while the friction coefficient of AlCrN coating is lower than that of TiAlSiN coating. Both the cutting force and cutting temperature of AlCrN coated tool are lower than TiAlSiN coated tool. The time required for the bluntness of the AlCrN coated tool is approximately 33.3% longer than that of the TiAlSiN coated tool, and the main wear mechanisms of both tools are mainly crater wear, diffusion wear and oxidation wear.

Improved Adhesion of TiAlSiN Nanocomposite Coatings on Cemented Carbide Substrate by Pre-Implantation

TiAlSiN coatings were deposited on YT 15 cemented carbide substrate by reactive direct current magnetron sputtering (DCMS) in a Plasma Immersion Ion Implantation and Deposition (PIII&D) system. The pre-implantation step and the coating deposition were carried out in the same experimental facility. In this article the effects of pre-implantation of several different elements (N, C, and O) were investigated. The adhesion strength, hardness, micro-structure, element concentration, depth profile, and the formation of coatings after the PIII experiments were characterized by a wide variety of techniques such as Rockwell indentation, scratch test, nano-indentation measurement, X-ray diffraction, energy dispersive spectroscopy, and Auger electron spectroscopy. The results showed that the adhesive strength of TiAlSiN coatings was significantly improved on samples pre-implanted with N and O whereas only slightly improved with pre-implantation of C. Additionally, the microstructure and mechanical properties of the TiAlSiN coatings were also altered through pre-implantation. The improved adhesion could be explained by the grain refinement and surface energy enhancement of the substrate by pre-implantation.

Effects of microstructure evolution on the oxidation behavior and high-temperature tribological properties of AlCrN/TiAlSiN multilayer coatings

AlCrN/TiAlSiN multilayer coatings have drown great attentions due to they combine both high hardness of TiAlSiN coating and outstanding oxidation resistance of AlCrN coating. In this study, AlCrN, TiAlSiN, and AlCrN/TiAlSiN multilayered coatings with two different multilayer designs: AlCrN/TiAlSiN-1 coating with fixed modulation period and ratio and AlCrN/TiAlSiN-2 coating with gradient increased AlCrN sub-layer thickness, were synthesized. The microstructure, mechanical property, thermal stability, oxidation behavior, and tribological performance of these coatings were comparably investigated. The variation of structure effects on the properties of the coatings were also discussed. The results indicated that the AlCrN/TiAlSiN multilayered coatings had superior performance than the monolayer AlCrN and TiAlSiN coatings. The AlCrN/TiAlSiN-2 coating also showed better thermal stability, oxidation resistance and high-temperature tribological properties compared to AlCrN/TiAlSiN-1 coatings, which can be attributed to the formation of a denser Al2O3 oxide layer on the surface of the coating.

Improvement on thermal stability of TiAlSiN coatings deposited by IBAD

ABSTRACTTiAlSiN coatings were deposited on Si substrates by ion beam-assisted deposition. The oxidation resistance and mechanism of TiAlSiN at 800°C, 900°C, and 1000°C under a nitrogen atmosphere were discussed and compared with those of TiAlSiN under argon and air atmospheres. The microstructure, bonding characteristics, and phase transition of the coatings were systematically investigated. The results indicated that nitrogen atmosphere effectively inhibited oxidation of the TiAlSiN coatings. The key reason for this improvement was that nitrogen maintained Ti–N and Si–N chemical bonds, and a dense Al2O3 layer was much more easily generated under the nitrogen atmosphere. We used first-principles calculations to investigate the electronic structures and bonding characteristics of TiAlSiN in this work.

Microstructure, mechanical properties, and cutting performance of TiAlSiN multilayer coatings prepared by HiPIMS

To explore mechanical properties of multilayer TiAlSiN coatings deposited on turning tools and their cutting performance against Inconel 718, TiAlSiN coatings with five different multilayer configurations, including single layer TiAlSiN-A (with higher adhesion strength), single layer TiAlSiN-B (with higher hardness), bilayer, four-layer, and eight-layer, were deposited using high power impulse magnetron sputtering (HiPIMS). The microstructure, chemical composition, hardness, adhesion, toughness and surface roughness of those coatings are measured and the cutting performance against Inconel 718 is analyzed. It is demonstrated that the multilayer structure results in an increase of both toughness and compressive stress of TiAlSiN coatings, and the one with eight-layer configuration shows the highest toughness among the five coatings. The results of the cutting experiment showed that eight layer coatings have maximum life while the TiAlSiN-A has minimum. This improvement of multilayer structure is believed to be due to the increasing toughness, which alleviates the damage caused by the frequent impact of Inconel 718 hard particles during cutting. This study also shows there is a negative correlation between spalling area of flank surface and adhesion of coatings.

Microstructure and tribological behavior of TiAlSiN coatings deposited by deep oscillation magnetron sputtering

AbstractDevelopment of pulsed‐techniques aimed to generate highly ionized target species and high plasma density opens up a new way to tailor composition, structure, and properties of coatings. In this work, TiAlSiN coatings have been deposited at various negative substrate biases (Vs) using deep oscillation magnetron sputtering by sputtering a TiAlSi compound target in Ar/N2 mixtures. The increase in Vs from −30 to −120 V resulted in a decrease in (111)‐preferred orientation and grain size, together with the increase in residual stress and rough morphology. The nc‐TiAlN/a‐Si3N4 nanocomposite structure was obtained in coatings. The highest hardness and Young's modulus reached 42.4 and 495 GPa at −120 V, respectively. However, at −60 V, the coatings with the highest H/E* and H3/E*2 ratios of 0.095 and 0.332 exhibited excellent adhesion with above HF1 level, the lowest coefficient of friction (COF) of 0.35 and specific wear rate of 2.1 × 10−7 mm3 N−1 m−1. Wear mechanism changed from the mixture of severe adhesive, oxidative and abrasive wear to mild oxidative wear to severe oxidative wear. TiAlSiN coatings with high hardness and H/E* and H3/E*2 ratios exhibited the decrease in COF and wear rate due to refined grains in uniform distribution, which well promoted oxide layers formed on sliding contact surface.