Formation Of Aluminum Nitride Research Articles

Formation of aluminum nitride in dross by contact-diffusion reaction during aluminum recycling

Secondary aluminum dross is a solid waste after aluminum extraction from the slag produced during aluminum recycling. It is classified as a hazardous waste due to the high content of active aluminum nitride (AlN). This work studied the thermodynamics and kinetics of AlN formation in aluminum dross. Aluminum tends to react with N2 to form AlN, when the partial pressure of nitrogen (N2) is much greater than that of oxygen (O2) (PN2≫PO2) in thermodynamics. Additionally, the reaction between aluminum and N2 is accelerated with the increasing temperature. Approximately 36.37 wt% of aluminum was transformed into AlN at 700°C according to kinetic analysis. Aluminum recycling involves smelting, refining, and dross processing. The dross produced from these different processes has various compositions and hazardous properties. The formation mechanism of AlN from the three processes was revealed based on the thermodynamic and kinetic analyses. The reaction mechanisms in these processes were identified as surface contact reaction, internal and surface contact reaction, and rotational surface contact reaction between the aluminum melt and N2, respectively. X-ray diffraction (XRD) and electron probe microanalysis (EPMA) analyses were used to determine the phase and composition of the aluminum dross. The nitrogen content in the aluminum dross from smelting, refining, and dross processing was found to be 3.3 wt%, 5.2 wt%, and 9.6 wt%, respectively. The monthly dross production were 276.3 tons, 22.7 tons, and 318.2 tons, respectively, according to statistics. It was calculated that the nitrogen generated in the three process was 9.12 tons, 1.18 tons, and 20.25 tons, respectively. Therefore, dross processing is the primary source of AlN. A rapid dross processing method with small-scale vertical stirring was proposed to shorten the reaction between the aluminum melt and N2, thereby reducing AlN formation. This work could provide guidance for reducing hazardous AlN in aluminum dross and optimizing the aluminum recycling process.

Advances in Room Temperature of Indium Aluminum Nitride InAlN Deposition via Direct Current (DC) Co-Sputtering for Solar Energy Applications

This study presents an innovative method for the synthesis of indium aluminum nitride (InAlN) layers by direct current (DC) co-sputtering at room temperature, with the aim of reducing production costs of optoelectronic devices. Indium and aluminum targets are used, varying the power applied to the aluminum target. The results show that increasing the target power favors the formation of aluminum nitride (AlN), which modifies the chemical composition of the material. The layers obtained present smooth surfaces with a roughness of less than 3 nm, which is beneficial for applications requiring interfaces with low defect density. Regarding the optical properties, it is observed that the optical bandgap varies between 1.8 eV and 2.0 eV, increasing with the target power. Hall effect measurements indicate a decrease in the free carrier concentration and an increase in the resistivity with increasing power. This approach allows for the synthesis of InAlN with properties suitable for optoelectronic applications, solar cells, photocatalysis, and photoelectrocatalysis at low cost.

Sustainability in the Manufacturing of Eco-Friendly Aluminum Matrix Composite Materials

The purpose of this work was to consolidate the eco-friendly Al–SiC composites prepared with various weight fractions of ceramic particles (0; 2.5; 5; 10; 15 wt.% SiC) in the energy-saving sintering process under vacuum and in a nitrogen atmosphere at 600 °C. The density of the manufactured composites was determined using Archimedes’ method. The mechanical properties and strength characteristics of the metal–ceramic interface were measured using three-point flexural and uniaxial compression tests, as well as the Brinell hardness measurement. The tribological properties were evaluated by determining the coefficients of friction and weight losses of the tested materials and identifying the tribological wear mechanisms. Advanced microstructural observation methods, such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), were used to analyze the microstructure of the composites in detail, including the identification of the phase composition using X-ray analysis methods. Low-cost composites with a porosity not exceeding 7% were successfully produced via energy-saving production routes. Simultaneously, owing to the formation of aluminum nitrides during sintering in a nitrogen atmosphere, these composites exhibited mechanical and tribological properties superior to those of materials sintered under vacuum.

To elucidate the effect of alloying elements for enhanced nitriding of aluminum: A multiscale computational study

The limitations of aluminum (Al) are discussed in certain industrial applications, owing to its low hardness and wear resistance. To overcome these limitations, surface modification techniques, such as the formation of aluminum nitride (AlN) layers on the Al surface, have been explored. However, conventional surface-nitriding processes have low productivity, and it is essential to develop a cost-effective method to ensure higher nitriding rates. This paper presents the results of a multiscale computational study on the atomic-scale mechanisms involved in gas nitriding processes and the effects of alloying elements on reaction kinetics using density functional theory calculations. This study also provides insights into the thermodynamic stability and kinetics of the process, contributing to the design and optimization of the nitriding process for the formation of AlN on Al surfaces using Thermo-Calc. and microkinetic analyses. This study demonstrates the potential of multiscale computational methods for advancing the understanding of surface modification techniques and their applications for nitriding on the surface of Al and suggests the best alloying element to enhance the nitriding rate.

Characterization of Structure, Morphology, Optical and Electrical Properties of AlN–Al–V Multilayer Thin Films Fabricated by Reactive DC Magnetron Sputtering

Composite thin films of the AlN–Al–V type, grown by magnetron sputtering, were analyzed by several complementary diagnostic methods. The power of the magnetron was used as a variable parameter, while gas flows, chamber pressure, and substrate temperature remained unchanged during the film fabrication. According to grazing incidence X-ray diffraction (GIXRD) results, in most cases, it was possible to obtain an (002)-oriented aluminum nitride (AlN) layer in the films, although, with an increase in the magnetron power to 800 W, the formation of X-ray amorphous AlN was observed. Similarly, according to the Raman results, the width of the peak of the vibrational mode E1, which characterizes the correlation length of optical phonons, also significantly increased in the case of the sample obtained at 800 W, which may indicate a deterioration in the crystallinity of the film. A study of the surface morphology by atomic force microscopy (AFM) and scanning electron microscopy (SEM) showed that the AlN film grows in the form of vertically oriented hexagons, and crystallites emerge on the surface in the form of dendritic structures. During the analysis of the AFM roughness power spectral density (PSD-x) functions, it was found that the type of substrate material does not significantly affect the surface roughness of the AlN films. According to the energy–dispersive X-ray spectroscopy (SEM-EDS) elemental analysis, an excess of aluminum was observed in all fabricated samples. The study of the current-voltage characteristics of the films showed that the resistance of aluminum nitride layers in such composites correlates with both the aluminum content and the structural imperfection of crystallites.

Physical nature of hardening of heat-resistant metal of high hardness formed by plasma in nitrogen medium

The structure, phase and chemical composition of a heat­resistant alloy formed by plasma in a nitrogen medium with subsequent high­ temperature tempering have been studied by scanning electron microscopy and microrentgenospectral analysis. It was found that in the deposited alloy, the main phases are a solid solution of α­iron and carbonitrides based on iron, tungsten, chromium, molybdenum, and aluminum (Fe 6 W 6 NC and AlN). High­temperature treatment (four­fold high­temperature tempering at a temperature of 580 °C for 1 h) of the deposited coating leads to an increase in the crystal lattice parameters (from 2.866 to 2.89 Å) and in the sizes of coherent scattering regions (from 25 to 100 nm), and to a decrease in internal elastic stresses (from 1000 to 600 MPa). A pronounced oriented dendritic structure is observed on the deposited surface. After surfacing and high­temperature tempering, the oriented dendritic structure is practically not visible. The distribution of microhardness over the depth of the deposited layer in the state after surfacing is characterized by a significant spread at its high average value on the surface of 4.142 GPa (dispersion 1.0956) and the middle part of the surfacing – 5.153 GPa (dispersion 1.5697). The spread of microhardness values is associated with the complex thermal effect of multilayer plasma surfacing along a helical line and mixing of the substrate material with the surfacing coating. High-temperature tempering leads to an equalization of the microhardness values and an increase in its average value to 5.7 – 6.5 GPa. The nature of hardening of the deposited heat­ resistant metal of high hardness, additionally alloyed with nitrogen and aluminum, was clarified. The main hardening of the deposited metal occurs at high temperature tempering due to an increase in the carbide and carbonitride phases and the formation of fine aluminum nitride.

In English

Boron carbide (BC, B15-xCx B4C) has a unique combination of properties. This makes it a material for priority applications for a wide range of engineering solutions. The high melting point and heat resistance of the compound contribute to its use in refractory conditions. Due to its extreme abrasion resistance, B4C is used as an abrasive powder and coating. Due to its high hardness and low density, B15-xCx has ballistic characteristics. It is usually used in nuclear programs as an absorbent of neutron radiation Boron carbide ceramics (B15-xCx or BC) may lose strength and toughness due to the amorphization effect under high shear stresses. Aluminum dodecaboride AlB12 or B12Al, as well as boron carbide B12 [(CCC) x (CBC) 1-x] have common structural units B12 family of boron-icosahedral structures. The bond between icosahedrons is mainly due to atoms (Al, Si, O) or chains (CMC), where M is Al, Si, B, C. Doping BC powder with a small amount of AlB12, in cases of shock-shear stress, triggers the mechanism of "micro-cracking". Micro cracks and pores are formed in ceramics. The breakdown voltage decreases. AlB12 synthesis is associated with known difficulties. On the other hand. The production of metal-ceramic materials for several decades is associated with the interaction of liquid aluminum and boron nitride. The calculation of this reaction shows that it is exothermic. Avoiding oxidation in vacuum, the reaction occurs through the formation of aluminum nitride and aluminum dodeca-boride. In contrast to the liquid state, the process continues until the end, at conditional temperatures of evaporation of aluminum with slight changes in vacuum. The reaction product is a mixture of nanosized AlN/AlB12 powders with a weight ratio of 3/1 ready for baking without grinding. The acid-base properties of the nanosized powder mixture AlN + AlB12, the products of the interaction BN + Al in vacuum, which are used optionally, emit separate in pure phases of aluminum nitride and aluminum dodeca-boride. The yield of AlB12 is ~ 25%, boron reaches ~ 100%. The average particle size of the AlB12 powders according to TEM and ACS X-rays (area of coherent X-rays scattering), L (nm) is LTEM=110-150nm, LACS=51-70nm. The average specific surface area of the powder according to BET, TEM and ACS, SBET.m2/g=21,0-15,0; STEM.m2/g=21,4-15,4; SACS.m2/g=46,1-33,6; (at 1460 and 1640K, respectively).

Preparation of Metal Nitride Particles Using Arc Discharge in Liquid Nitrogen.

A simple process to synthesize metal nitride particles was proposed using submerged arc discharge plasma in liquid nitrogen. Gibbs standard free energy was considered for the selection of the nitride-forming materials. In this study, titanium (Ti) and aluminum (Al) electrodes were used as raw materials for nitride particle preparation. Liquid nitrogen acted as a dielectric medium as well as a nitridation source in this process. A copper electrode was also used as a non-reactive material for comparison with the reactive Ti and Al electrodes. As the operating conditions of the experiments, the arc discharge current was varied from 5 A (low-power mode) to 30 A (high-power mode). The formation of titanium nitride (TiN) and aluminum nitride (AlN) was confirmed in the particles prepared in all experimental conditions by X-ray powder diffraction (XRD). The observation using a field emission scanning electron microscope (FE-SEM) and a field emission transmission electron microscope (FE-TEM) indicated that the synthesized TiN particles showed a cubic morphology, whereas AlN particles containing unreacted Al showed a spherical morphology. The experiments using different metal electrode configurations showed that the anode generated most of the particles in this process. Based on the obtained results, a particle formation mechanism was proposed.

Determination of Thermodynamic Characteristics of Phase-stabilized Ammonium Nitrate-Based High-energy Solid Combustible Materials

ABSTRACT The thermodynamic and physical characteristics of the starting components and the synthesized high-energy solid combustible materials are determined. It was established that the reaction of the formation of aluminum nitride in the endothermic mode is possible at a temperature of about 3000 K. The adiabatic combustion temperatures of the synthesized fuel systems in the combustion chamber are calculated. The dependence of the values of the adiabatic temperature and specific impulse on the excess of the oxidizing agent, the nature of the binder and energy additives is established.

The influence of substrate bias and sputtering pressure on the deposited aluminium nitride for magnetoelectric sensors

A residual stress of Aluminium nitride (AlN) thin films has been a problem in the magnetoelectric (ME) composites that are used in the AC magnetic field sensors. The present work aims to optimize the deposition process of AlN in order to fabricate a nearly-zero stress of AlN thin films as well as ME composites without losing the microstructural and piezoelectric properties. The influences of RF bias power and sputtering pressure on the residual stress, microstructure, and piezoelectric response have been investigated. Two different stacks are deposited on Si/SiO2 substrates: Ta/Pt/AlN and Ta/FeCoSiB/Ta/Pt/AlN. Pulsed DC reactive sputter depositions have been performed to deposit AlN films. With increasing the substrate bias, stress of the AlN films and the stacks with the magneto strictive layer are augmented. A variation of the sputtering pressure is a promising way to fabricate nearly zero stress of the AlN films and the stacks without the magneto strictive layer. A transition from tensile to compressive stress has been observed at the low sputtering pressure. Sputtering pressure also affects the stress of AlN films and the stacks with the magneto strictive layer. FWHM of AlN (0002) peaks are nearly constant within the ranges of the substrate bias. By reducing the sputtering pressure, FWHM is broadened due to lower ionization degree associated with AlN formation and greater number of micro-arcs. However, the magnitude of e31,f is increased due to a lower residual stress at the low sputtering pressure.

Reduction of harmful effects of nitrogen on the properties of low-carbon steel 08Y by electing a rational amount of nitride-forming elements

Based on the thermodynamic analysis of nitride formation reactions, the advantage of titanium nitride formation and the lowest probability of boron nitride formation are established. Based on the analysis of experimental data, an analytical expression was established to calculate the required amount of titanium additives to neutralize the harmful effects of nitrogen, which also takes into account the concentration of aluminum in steel and prevents the formation of harmful aluminum nitrides. Necessary and sufficient concentrations of boron in steel are calculated to start the nitride formation reaction and to provide a strengthening effect associated with the formation of boron nitrides. Thermodynamic calculations and based on the analysis of the results of previous experimental melts of low-carbon steel, it is shown that the activity of oxygen in the intermediate to obtain particularly low-carbon steel should be such as to ensure the removal of carbon from it to a given limit, as well as the amounts of carbon deoxidized steels from ferroalloys and electrodes when heating steel on ladle-furnace installations, as well as from periclase-carbon lining-stalkovsha (carbon content in the area of the slag belt 10-12%, in the lining of the walls and bottom - 6%). The consumption of aluminum at the outlet of the furnace should be correlated with the degree of peroxidation of the metal, which would be desirable to stabilize and reduce the precipitation of silicomanganese and ring-containing ferroalloys. When organizing the evacuation of steel, reducing the pressure in the vacuum chamber to 100 mbar is theoretically sufficient for the predominant oxidation of carbon in comparison with manganese and silicon in the entire temperature range of the process. When evacuating non-deoxidized aluminum metal, the final carbon content in the metal of 0.01% is achieved even at its initial content of 0.074%. Due to the use of vacuum oxygen decarburization reaction without additional introduction of oxygen in gaseous form or in the form of oxides, it is possible to obtain a low-carbon metal with a guaranteed carbon content of 0.01% in the finished metal and a minimum manganese content of 0.12% and silicon up to 0.02 %, which provides high plastic properties of the metal. Keywords: low carbon steel, nitrides, titanium, boron, aluminum, vacuum carbon deoxidation

Low-Temperature Synthesis of Aluminum Nitride by Addition of Ammonium Chloride.

Aluminum nitride (AlN) is highly insulating and has a high thermal conductivity. AlN also has the advantages of being nontoxic and chemically stable. Therefore, it is a suitable sealing material for electric devices. Previous studies have shown that the addition of NH4Cl has a large influence on the formation of AlN and can effectively be used in its low-temperature synthesis without the use of special equipment. However, it has not been clarified whether NH4Cl simply promotes the reaction between Al and nitrogen or directly contributes to the nitridation reaction. In this study, which was part of a series of studies on the development of low-temperature synthesis methods for AlN, the nitridation behaviors of Al in Al–N2, Al–NH4Cl–N2, and Al–NH4Cl–He systems were determined, and the effects of the heating temperature and amount of NH4Cl on the nitridation behavior were examined in detail. When NH4Cl was added, AlN began to form at 600 °C, a formation temperature that was approximately 200 °C lower than that when only Al powder was heated under a nitrogen stream. The fact that the formation of AlN was also observed when the NH4Cl-added Al powder was heated under a helium gas stream confirmed that nitrogen derived from NH4Cl contributed to the formation of the AlN. Furthermore, based on the experimental results, the reaction mechanism was clarified, and the kinetic parameters for the nitridation of Al were determined.

Formation of α/β‐Si3N4nanoparticles by carbothermal reduction and nitridation of geopolymers

AbstractSilicon nitride (Si3N4) particles with various α/β‐Si3N4ratios were fabricated from geopolymer (GP)‐carbon compositions (M2O·Al2O3·4.5SiO2·12H2O+18C), where M is an alkali ion (Na+, K+and Cs+). They were made by carbothermal reduction and nitridation at 1400°, 1500°, and 1600°C for 2 hours under flowing nitrogen. Characterization of carbothermally reacted GP‐carbon compositions was based on XRD, SEM‐EDS, HRTEM, and selected area electron diffraction analyses. Depending on the alkaline composition of GP, the carbon content and the reaction temperature, a compositionally variable α/β‐Si3N4or SiAlON was achieved. Crystallization of the GPs gradually increased by heat treatment over 1400°C with corresponding weight loss. It was found that NaGP, KGP, and CsGP crystallized into a major phase of α‐Si3N4, β‐Si3N4, and SiAlON, respectively. Prolonged heating at 1600°C led to an increase in the α/β‐Si3N4ratio in NaGP due to the formation of aluminum nitride, while it led to a decrease in α/β‐Si3N4ratio in KGP. In the case of CsGP, SiAlON replaced the pollucite which mainly formed at lower temperatures. Transmission electron microscopy revealed that the needle‐like particles were of ~0.5 µm in size and consisting of α/β‐Si3N4mixtures.

Enhancement of Mechanical and Structural Traits of Aluminum Using Low Energy Plasma Focus Device

AbstractOwing to good machinability, low weight and high specific strength, aluminum is widely used in aerospace and automotive industries. However, low mechanical strength limits its wide spread use in mainstream industries. In this study, nitriding of aluminum was performed with a stream of low energy ions in 1.8 kJ Mather type dense plasma focus (DPF) device. The axial distance from the anode tip was varied in steps to study the effect of the stream length on structural and mechanical properties of the nitrided samples. XRD and Raman analysis confirmed the formation of aluminum nitride (AlN) on the plasma exposed surface. Williamson‐Hall (W−H) study revealed significant improvement in crystallinity and strain of the nitride samples. The most favorable results on mechanical and structural properties of the nitrided samples were obtained at an axial distance of 10 cm. The improved texture and maximum dislocation density for typical AlN (311) is obtained at the optimum distance. The micro‐hardness of the nitrided samples was measured ∼4.5 times higher than the base material.

Особливості формування структури та фазового складу в процесі реакційного спікання кубічного нітриду бору зі сполуками Ti, Cr, V

Influence of sintering temperature on both phase composition and structure of ceramic matrix composites based on cubic boron nitride with binders in a form of Al and the Ti, Cr, V carbides are investigated by methods of physical materials science. As the object of study, three cBN–TiC–Al, cBN–Cr3C2–Al, cBN–VC–Al compositions containing 60% vol. cBN are selected. The composites are obtained by high-pressure high-temperature (HPHT) sintering in high-pressure apparatus AVTT-30 in the temperature range of 1600– 2450°C under pressure of 7.7 GPa. In the process of HPHT sintering of composites in the cBN–TiC–Al and cBN–Cr3C2–Al systems, the formation of titanium and chromium diborides is found at the temperatures of sintering Тsint ≥ 1850°С and Тsint ≥ 2150°С, respectively, simultaneously with the formation of alu-minium nitride. (Less)

Synthesis of Aluminum Oxynitride Nanopowders in a Plasma Reactor with a Confined Jet Flow

Experimental studies on the synthesis of aluminum oxynitride nanopowders in a reactor with a confined plasma jet by the interaction of disperse aluminum with ammonia and oxygen in a flow of nitrogen plasma generated in an electric arc plasma torch are performed. Preliminary calculations of the equilibrium compositions and thermodynamic characteristics of the multicomponent Al–O–N system are carried out. An optimal design of the reaction prechamber of the reactor is performed. Powders having a cubic structure and consisting of aluminum oxynitride phases with an average particle size in the range from 20 to 200 nm are obtained. It is established that the specific surface area of the obtained powders increases from 20 to 71 m2/g, and the nitrogen content in the nanopowders increases from 3.6 to 14.7 wt % with an increase in the flow rate of quenching gas from 1.8 to 6.0 m3/h. At the same time, the oxygen content decreases from 35.5 to 25.5 wt %. At a minimal flow rate of the quenching gas, the metallic aluminum and its oxide phases are present in the obtained powders. With an increase in the amount of quenching gas, the conditions for the mixing of aluminum vapors with oxygen and atomic nitrogen from decomposing ammonia are improved, which leads to the formation of aluminum oxynitride and aluminum nitride. The variation of the synthesis parameters allows us to obtain aluminum oxynitride nanopowders having a specific surface area ranging from 28 to 50 m2/g containing from 1 to 11 wt % of nitrogen and from 25 to 40 wt % of oxygen.

Studies on Preparation and Characterization of Aluminum Nitride-Coated Carbon Fibers and Thermal Conductivity of Epoxy Matrix Composites

In this work; the effects of an aluminum nitride (AlN) ceramic coating on the thermal conductivity of carbon fiber-reinforced composites were studied. AlN were synthesized by a wet-thermal treatment (WTT) method in the presence of copper catalysts. The WTT method was carried out in a horizontal tube furnace at above 1500 °C under an ammonia (NH3) gas atmosphere balanced by a nitrogen using aluminum chloride as a precursor. Copper catalysts pre-doped enhance the interfacial bonding of the AlN with the carbon fiber surfaces. They also help to introduce AlN bonds by interrupting aluminum oxide (Al2O3) formation in combination with oxygen. Scanning electron microscopy (SEM); Transmission electron microscopy (TEM); and X-ray diffraction (XRD) were used to analyze the carbon fiber surfaces and structures at each step (copper-coating step and AlN formation step). In conclusion; we have demonstrated a synthesis route for preparing an AlN coating on the carbon fiber surfaces in the presence of a metallic catalyst.

Effect of carbon contamination on the sintering of alumina ceramics

The present work aimed with the carbon contamination in alumina ceramics and its influence on sinterability of alumina in low vacuum and atmospheres of argon and nitrogen. The commercially available alumina was coated with carbon and sintered at different atmospheres to investigate the effect of carbon presence on alumina sintering behaviour. The sintering conditions were: heating/cooling rates 5°C/min and 1.7°C/min until the maximum temperature of 1400°C and a dwell time of 2h. The microstructure of the samples was investigated from fracture and surface, prior to polishing, chemical or thermal etching. The non-densified (porous) surface layer was found in the samples sintered in nitrogen and vacuum, however, sintering in argon atmosphere showed a negligible effect on the surface. The core of investigated specimens exposes a transgranular/intergranular fracture mode and is dense in all cases. In the case of vacuum sintering, the strong carbon diffusivity was also noticeable by the dark grey color of the samples. Interestingly, the formation of aluminium nitride took place during sintering of carbon coated alumina samples in a nitrogen atmosphere at 1400°C. The thickness of the reactive porous layer was approximately 15μm beneath the surface. Such a porous layer is inappropriate to the desired features of final ceramic products. Presented results lead to better understanding of the sintering behaviour of ceramic and to suitable selecting of the set-up by densification conditions.

Nitrogen Trapping Ability of Hydrogen-Induced Vacancy and the Effect on the Formation of AlN in Aluminum

This paper presents the ternary interaction of N, H, and vacancy point defects and the nitrogen trapping ability of aluminum vacancies induced by hydrogen by means of DFT methods employed in VASP (Vienna Ab initio Simulation Package) and Abinit packages. The obtained vacancy formation energy of 0.65 eV is close to experimental values. Although the N–vacancy complex is unstable with the negative binding energy of −0.51 eV, the stability of H–vacancy–N is proved by the positive binding energy of 0.59 eV and the appearance of the orbital hybridization in the density of state (DOS) of atoms connecting to this complex. Moreover, Al vacancies can trap more than 4 N atoms, which prevents the formation of aluminum nitride and subsequently affects not only the hardness of the Al surface but also many practical applications of AlN coating.

Nitridasi Bahan Cor-Ten Untuk Meningkatkan Kekerasan dan Ketahanan Korosi Suhu Tinggi

Samples of Cor-Ten steels have been subjected to surface treatment, by coating Al and followed by nitridation. High-temperature corrosion tests were carried out using a Thermo Gravimetry Analysis / Magnetic Suspension Balance (TGA/MSB). The Nitridation process was performed at 550°C for 3, 5, 4, 7 and 20 hours under flowing N2 and NH3 gases. Corrosion tests were performed for 50 hours at 650°C. After the oxidation, sample were characterized using X-Ray Diffractometer (XRD) to determine the crystal structure, and then using Scanning Electron Microscope (SEM) to observe the microstructure and hardness of the alloys by aloowing Micro Hardness Tester. It can be concluded that sample nitridized for 5 hours showed the lowest corrosion rate or highest corrosion resistance, due to the corrosion barrier was Al2O3 protective layer. The hardness of Cor-Ten increased from 137 VHN to 340VHN (after nitridation), and to 744 VHN after Al deposition and nitridation for 5 hours. The increase of hardness might be associated with the formation of aluminum nitride. Keywords: Al Deposition, Corrosion Resistant, Cor-Ten, Nitridation, TGA/MSB, XRD, SEM