TiAlN Research Articles

Influence of the Al content on the in vitro bioactivity and biocompatibility of PVD Ti1−xAlxN coatings for orthopaedic applications

The biomedical applications of titanium aluminium nitride (Ti1−xAlxN) coatings strongly depend on roughness, wettability and aluminium content.

Study of cutting properties and wear pattern of carbide tools with comprehensive chemical-thermal treatment and nano-structured/gradient wear-resistant coatings

The paper is focused on the challenges to improve the life of carbide cutting tools through the deposition of a modifying composite wear-resistant multi-phase complex on the working surface, formed on the basis of the developed comprehensive surface treatment. The developed wear-resistant complex contains complex carbides of hafnium, formed by preliminary alloying of the surface of the carbide, and multi-layered composite coatings on the basis of system titanium aluminum nitride ((TiAl)N), obtained by subsequent deposition. The paper includes studies of the complex structure of the wear-resistant complex to be deposited on the surface of the cemented carbide and studies of the mechanism of wear and cutting properties of carbide tools with the developed comprehensive treatment. The studies have shown that the application of the comprehensive surface treatment can increase the life of carbide tools by 3–3.5 times in comparison with the life of an uncoated tool and by two times in comparison with the life of carbide tools coated with standard titanium nitride (TiN).

Reaction synthesis of Ti2AlN MAX-phase

Ti2AlN MAX-phase was synthesized from the powder mixtures of Ti–AlN using the reactionary sintering method. The optimal synthesis mode for the compound containing less than 1 % of TiN impurity phase was determined: isothermal annealing at 1300 °C for 2 hours in argon at a pressure of 3 atm. The preliminary mechanical activation and the reaction synthesis environment were investigated as the factors that can influence the yield of the Ti2AlN phase. It is shown that the activation increases the level of TiN secondary phase. It was also found that the vacuum synthesis does not enable obtaining of single-phase Ti2AlN.

Karakteristik Aus Mata Pisau Terlapisi Bahan Pengeras pada Pemotongan Kayu Mersawa dan Papan Partikel

The use of mersawa wood and particleboard as a materials has been increasing for building constructions and decorative purpose. In previous study reported that, these materials provide a high rate of wear caused by abrasion (high silica) and resin content. This article presents the characteristics of wear on the clearance face of newly multilayer-coated K10 cutting tools when milling mersawa wood and particleboard. The K10 cutting tools were coated with monolayer titanium aluminum nitride (TiAlN), multilayer TiAlN/titanium silicon nitride (TiSiN), and TiAlN/titanium boron nitride (TiBN). Mersawa wood with density of 0.80 g/cm3 and particleboard with a density of 0.61 g/cm3 were cut using the coated tools and uncoated K10. Cutting tests were performed on computer numeric control router at a high cutting speed of 17 m/s and a feed rate of 0.1 mm/rev to investigate the wear characteristics on the clearance face of these coated tools. Result of research shown that the coated tools experienced a smaller amount of wear than the uncoated tool when cutting the mersawa and particleboard. The best coating among other coated in this study was multilayer TiAlN/TiBN. The high hardness, low coefficient of friction, high resistance to oxidation, and high resistance to delamination wear of the multilayer-coated TiAlN/TiBN tool indicate a very promising applicability of this coating for high-speed cutting of abrasive woods and wood based materials.

Enhancement of Wear Properties on High Speed Steel Tool Using PVD Coating Technique<sup></sup>

Engineering industries are currently using many tool materials such as ceramic,carbide, high speed steel, Cubic Boron nitride and diamond. In most of the small scale industries, the lathe machines are consuming High Speed Steel (HSS) Tool. The HSS tools are easily available and cheapest one. In this present investigation, the Tungsten HSS Single point cutting tool was taken as substrate material. Two substrate HSS Tools were coated with two different combinations of TiAlN composite material using Physical Vapour Deposition coating technique. The surface roughness and hardness were determined for the tools in same condition. The tools were used in lathe machine in same operating condition. The weights of the tools were checked using standard equipment after each machining trials. The loss of tool weight for each trial was determined and the percentage of weight loss was calculated. The life of the Titanium Aluminium Nitride (Ti 70% , Al 25%) coated tool increased by 3.74 times than uncoated tool. The life of the Titanium Aluminium Nitride (Ti 55% , Al 35%) is increased by 2.71 times than uncoated HSS tool.

Microstructure and high temperature oxidation resistance of in-situ synthesized TiN/Ti3Al intermetallic composite coatings on Ti6Al4V alloy by laser cladding process

High temperature anti-oxidation TiN/Ti3Al intermetallic composite coatings were fabricated with the powder and AlN powder on Ti6Al4V titanium alloy surface by 6 kW transverse-flow CO2 laser apparatus. The chemical composition, morphology and microstructure of the TiN/Ti3Al composite coatings were characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectrometer (EDS). In order to evaluate the high temperature oxidation resistance of TiN/Ti3Al coating, the isothermal oxidation test was performed in a high temperature resistance furnace at 600 °C and 800 °C, respectively. The result shows that the composite coating has a rapidly solidified fine microstructure consisting of TiN primary phase (granular-like, flake-like or dendrites), with an even distribution in Ti3Al matrix. It indicates that a physical and chemical reaction between Ti powder and AlN powder has completely occurred under the laser irradiation condition. In addition, the microhardness of the TiN/Ti3Al intermetallic composite coating is 3.4 times higher than that of the Ti6Al4V alloy substrate and reaches 844 HV0.2. The high temperature oxidation behavior test reveals that the high temperature oxidation resistance of TiN/Ti3Al composite coating is much better than that of titanium alloy substrate. The excellent high temperature oxidation resistance of TiN/Ti3Al intermetallic composite coating is attributed to the formation of reinforced phases TiN, Al2O3 and TiO2. The laser cladding TiN/Ti3Al intermetallic composite coating is anticipated to be a promising high temperature oxidation resistance coating for Ti6Al4V alloy.

Behavior of coated forming tools with TiAlN coatings grown by Triode Magnetron Sputtering

This research focusses on tribological analysis of Titanium Aluminum Nitride (TiAlN) coatings deposited by means of Triode Magnetron Sputtering, when used as a protective coating on forming tools. The analysis is carried out from the microstructural properties which directly influence the tribological behavior. It was observed that the predominant wear mechanisms on the surface are delamination and tribo-oxidation; an increase in the useful life of the tool was observed making hard coatings an excellent alternative in the metalworking industry.

Impact of Tool Inserts in High Speed Machining of GFRP Composite Material

Composite materials are in-homogenous, anisotropic and cause high tool wear at high cutting speeds in machining. Industrial practices worldwide reveal a need to use high speed machining to achieve the desired material removal rate, surface finish and to reduce cost cutting. In this research work, impact of turning glass fibre reinforced polymer tube with two contrasting turning tool inserts such as titanium aluminium nitride and tungsten carbide have been analysed. The turning was conducted at low to high cutting conditions up to spindle speeds of 2000 rpm and feed rate of 0.446mm/rev. The cutting force, feed force were acquired with a strain gauge based dynamometer, the chip cross section was observed using scanning electron microscopy and the temperature was sensed with a infra red thermo sensor. The advanced titanium aluminium nitride insert shows better machining characteristics across cutting speeds.

Improvement of Wear Performance of High Speed Steel Tool Using Physical Vapour Deposition Coating Process

Manufacturing industries are presently using many tool materials, such as high speed steel, carbide tool and diamond tools etc. The most widely and commonly used tool in the engineering industries is high speed steel (HSS). The HSS tools are the cheapest and reliable for medium and small scale industries. In this work, the HSS single point cutting tool is taken as substrate material and coated with two different combinations of TiAlN composite coating using Physical vapour deposition (PVD) technique. Also, Tool life was calculated and compared with uncoated HSS tool. The hardness and surface roughness value for both the tools have been taken under same condition. The loss of weight in the tool after machining has been weighed using standard equipments. The differences have been closely observed with sufficient trials and find out the loss in weight in both the tools. The weight loss percentage was calculated after proper machining trials. The tool life of the Titanium Aluminium Nitride (Ti 70%, Al 25%) coated tool has been increased by 3.74 times than that of uncoated tool. The surface finish for TiAlN (Ti 70%, Al 25%) coating is better than the uncoated tool. The PVD coated tools having better performance comparing with uncoated HSS tool.

Corrosion resistance appraisal of TiN, TiCN and TiAlN coatings deposited by CAE-PVD method on WC–Co cutting tools exposed to artificial sea water

A new advanced sintered composite cutting tool has been developed based on tungsten carbide matrix ligated with cobalt (WC–Co) additivated with tantalum carbide (TaC), titanium carbide (TiC) and niobium carbide (NbC) as grain growth inhibitors. Titanium nitride (TiN), titanium carbonitride (TiCN) and titanium aluminium nitride (TiAlN) coatings were deposited on these tools by CAE-PVD technique to find out the best solution to improve the corrosion resistance of this tool in marine environment. The electrochemical behaviours of the specimens in 3.5% NaCl water solution were estimated by potentiodynamic polarization measurements i.e. the open circuit potential (Eoc), corrosion potential (Ecorr) and corrosion current density (icorr). Wide angle X-ray diffraction (WAXD), optical microscopy (OM) and atomic force microscopy (AFM) investigations have been carried on tested and untested specimens to substantiate the corrosion resistance of the tested specimens. Based on the open circuit potential (Eoc) and corrosion potential (Ecorr) results, the tested specimens were ranked as TiN, TiAlN, TiCN and WC–Co while on corrosion current density (icorr) and protective efficiency (P) values they have been ranked as TiN, TiAlN, WC–Co and TiCN. The WAXD, MO and AFM results unambiguously show that the corrosion resistance depends on the nature and morphology of the coating.

Effects of Supplying Oil Mist and Water Mist with Cold Air on Cutting Force and Temperature in End Milling of Difficult-to-Cut Materials

This paper discusses the cutting temperature and cutting force in end milling difficult-to-cut materials cooled with several types of mists and low-temperature air. The cutting tool was a throwaway end mill with a carbide tip coated with titanium aluminum nitride. The Ti-6Al-4V titanium alloy and AISI D2 hardened steel were used as workpieces. The tool flank temperature and cutting force were measured simultaneously during side milling. The temperature was measured using a two-color pyrometer with an optical fiber. Oil mist and water mist from a mist generator were supplied to the cutting point along with cold air at approximately -27 °C. Compared with dry cutting, the cooling effects of supplying an oil mist and/or cold air were less than for other supply conditions in titanium alloy cutting. However, when water mist was added, the tool flank temperature clearly decreased. The cutting force increased for cases that included water mist. The adhesion of the titanium alloy to the cutting edge of the worn tool was significantly suppressed by supplying water and oil mist with cold air. Tool flank wear also decreased under those lubrication conditions.

In situ formation of substrate release mechanisms for gas metal arc weld metal 3-D printing

This study provides an in-depth investigation into low-cost and no-cost substrate release mechanisms that allow gas metal arc weld 3-D printed ER4043 aluminum and ER70S-6 steel parts to be removed from a reusable print substrate with minimal energy. Aluminum oxide, boron nitride, and titanium nitride coatings were evaluated as possible substrate release agents for aluminum printing. Additionally, the in situ formation of substrate release agents such as intermetallics and oxides were tested for both aluminum and steel printing. Testing was performed with a modified Charpy impact tester to remove 3-D printed metal parts from an 1100 aluminum or A36 low carbon steel print substrate to assess the impact energy required for removal. Specimen porosity was measured prior to sectioning and microstructural analysis, hardness traverses were measured across the specimens, and the elastic and shear moduli of the parts were analyzed via ultrasonic methods. All of the employed substrate release mechanisms minimized weld penetration and, in some instances, formed a brittle phase with the print substrate that allowed the specimens to be removed with minimal impact energy. These results thus provide methods with the removal of metal 3-D printed parts from print substrates with no specialized tooling or equipment conducive to distributed manufacturing.

Milling of Austempered Ductile Iron (ADI) with recycled carbide tools

Ductile iron with austenitic-ferritic matrix (ADI), due to the specific heat treatment, shows an advantageous combination of engineering properties. The superior wear resistance and strength-to-weight ratio, together with high stress resistance and good ductility, make such material suitable for cost- and weight-efficient automotive structural applications. In this paper, results of milling experimental trials carried out on ADI 1200 are discussed. Tests were performed using uncoated and titanium aluminium nitride (TiAlN) or titanium carbo-nitride (TiCN)-coated cutting inserts obtained from both recycled and traditionally prepared tungsten carbide-cobalt (WC-Co)-based materials. Results show that satisfactory milling performance was obtained even by using recycled cutting materials, particularly when coated.

Milling damage on Carbon Fibre Reinforced Polymer using TiAlN coated End mills

This paper reports on the damage caused by milling Carbon Fibre Reinforced Composite (CFRP) with 2-flute 4 mm-diameter solid carbide end mills, coated with titanium aluminium nitride. The machining parameters considered in work are, rotation speed, feed rate and depth of cut. Experiments were designed based on Box-Behnken design and the experiments conducted on a Mikrotool DT-110 CNC micro machine. A laser tachometer was used to ascertain a rotational speed for conducting any machining trial. Optical microscopy examination reveals minimum delamination value of 4.05 mm at the spindle speed of 25,000 rpm, depth of cut of 50μm and feed rate of 3 mm/min and the maximum delamination value of 5.04 mm at the spindle speed of 35000 rpm, depth of cut of 150μm and feed rate of 9 mm/min A mathematical model relating the milling parameters and delamination has been established.

Tool Life and Wear Mechanism when Machining LM6 Aluminium (MMC) with Coated and Uncoated High Speed Steel

This paper aims to study the tool life of coated and uncoated high speed steel (HSS) when machining LM6 aluminium. The experiment was carried out in dry condition with spindle speed of 5000 rpm and 6000 rpm, and feed rate of 90 mm/min and 120 mm/min. Axial and radial depth of cut remain constant at 0.5 mm and 1.0 mm, respectively during the experiment. Throughout the experiments, coated HSS showed higher tool life as compared to uncoated HSS due to the coating layer of titanium aluminium nitride (TiAlN) provides protection from rapid wear during machining. For both cutting tools, the optimum cutting parameter was recorded at 5000 rpm spindle speed, 90 mm/min feed rate, 0.5 mm axial depth of cut and 1.0 mm radial depth of cut. Some evidence of built up edge (BUE) formation were observed at most of cutting tools, showing the dominant wear mechanisms appear to be adhesive wear.

Effect of plastic incompatibility on the strain hardening behavior of Al–TiN nanolayered composites

The strain hardening behavior of Al–TiN nanolayered composites induced by plastic incompatibility was studied by 3-D discrete dislocation dynamics (DDD) simulations. Our simulations results indicate the strain hardening rate solely induced by the plastic incompatibility is independent of layer thickness and dislocation density at a constant layer thickness ratio, while the yield stress exhibits a strong size effect. Furthermore, the strain hardening rate increases with decreasing Al/TiN layer thickness ratio and our predicted results match well with prior experiment data.

Study on the Interface Characteristics of Cemented Carbide after Stripping Ti Department Coatings

TiAlN Coatings were stripped by chemical method, which were deposited on Y WZ Alloy by arc ion plating. The surface morphology and composition of the cemented carbide after stripping TiAlN coatings by chemistry method were analyzed. It was found that TiA1N coatings on the cemented carbide substrates could be removed by being taken in 30% of hydrogen peroxide and potassium oxalate in alkaline mixed solution (V(NaOH so1ution):V(3O%H2O2):V(COOK solution) = 1:1:1) at 45 °C for 45 minutes. The surface of the cemented carbide substrate was bright, and the color was the same as that before depositing TiA1N coatings. The surface of the substrate after removing was studied by X-ray photoelectron spectrum (XPS). The results showed that binding energies of the W element and the main peak of N element on the substrate surface were much close to the criterion binding energy in the XPS data-base; and the valence of the element on the YW2 alloy changed little. The Al, Ti and N elements diffusing into the superficial zone of the sample during the coating depositing process made their contents increase and the band energy location offset after stripping the coating. TiN and A1N were formed, which benefit to increase the film-substrate cohesion during re-preparing coatings. The influence of stripping solution on the corrosion degree of cemented carbide substrate was small.

Bias voltage influence on the mechanical and tribological properties of titaniumaluminum nitride coatings produced by triode magnetron sputtering

TixAl1-xN coatings were grown using the triode magnetron sputtering technique with various bias voltages between -40 V and -150 V. As the bias voltage increased, an increase in the Al atomic percentage was observed, presenting a competition with Ti and producing structural changes. Moreover, the grain size and roughness were also strongly influenced by the bias voltage. It was observed that coatings with concentrations of approximately 25% Al and 75% Ti exhibited an optimum mixture of mechanical and tribological properties. The average coefÞcient of friction was low for the TiAlN coating that was grown at -40 V. Additionally, the critical load was obtained by measuring the adhesion using the scratch test.

Deposition and characterization of titanium aluminum nitride coatings prepared by RF magnetron sputtering

The aim of this study is to investigate the influence of plasma deposition parameters (the pressure and the substrate bias voltage Vs) on structure, surface morphology, hardness and electrochemical behavior (studied by potentiodynamic polarization and optical microscope (OM) in aggressive environment NaCl 3.5wt%) of TiAlN coatings. The coatings were deposited by reactive RF magnetron sputtering (13.56MHz). They were carried out during 60min and their thickness was approximately 1μm. Structural analysis shown that TiAlN coating crystallized in cubic (fcc) and hexagonal (hcp) structure with orientations in (100), (111), (200), (110), (220) and (311) planes. The deposited coatings present maximum hardness (H=25.75GPa) and Young's modulus (E=479.82GPa) at low pressure (20mTorr) and −60V of negative substrate bias. Also, mechanical properties (H&E) were strongly influenced by coatings density and grain size. Electrochemical tests revealed that XC48 steel substrate covered with TiAlN coating exhibits excellent corrosion resistance.

The Mechanical and Tribology Properties of Sputtered Titanium Aluminum Nitride Coating on the Tungsten Carbide Insert Tool in the Dry Turning of Tool Steel

The Mechanical and Tribology Properties of Sputtered Titanium Aluminum Nitride Coating on the Tungsten Carbide Insert Tool in the Dry Turning of Tool Steel