Characterisation of Mo–V–N Coatings Deposited on XC100 Substrate by Sputtering Cathodic Magnetron

The aim of this work is the characterization of ternary molybdenum–vana¬dium nitride (Mo–V–N) coatings deposited on silicon and XC100 steel substrates by the reactive radiofrequency dual magnetron sputtering with different contents of the Mo and V targets and nitrogen as reactive gas. The metal-target bias voltages are varied from 300 to 900 V. The hardness, surface morphology, microstructure and composition are studied by nanoindentation, scanning electron microscopy, atomic-force microscopy, and x-ray diffractometry. The Mo–V–N films manifest pyramidal surface morphology, high roughness (of 13.5 nm), but low mechanical properties. Hardness and Young’s modulus are found in the ranges of 10–18 GPa and 100–335 GPa, respectively. The residual stresses of coatings are compressive and varied between 0.8 GPa and 2.5 GPa (calculated with the Stoney formula).Целью этой работы является характеризация покрытий, изготовленных из трёхкомпонентного молибден-ванадиевого нитрида (Mo–V–N), которые наносились на кремниевые и стальные (ХС100) подложки с помощью реактивного радиочастотного магнетронного двухкатодного распыления мишеней с различным содержанием Mo и V с использованием азота в качестве реагирующего газа. Напряжения смещения металлической мишени варьировались от 300 до 900 В. Твёрдость, морфология поверхности, микроструктура и состав изучались при помощи наноиндентирования, сканирующей электронной микроскопии, атомно-силовой микроскопии и рентгеновской дифрактометрии. Плёнки Mo–V–N обладают пирамидальной морфологией поверхности, высокой шероховатостью (13,5 нм), но низкими механическими свойствами. Твёрдость и модуль Юнга находятся в диапазонах 10–18 ГПа и 100–335 ГПа соответственно. Остаточные напряжения в покрытиях (рассчитанные по формуле Стони) являются сжимающими и изменяются в пределах от 0,8 до 2,5 ГПаМетою даної роботи є характеризація покриттів із трикомпонентного молібден-ванадійового нітриду (Mo–V–N), що наносилися на кремнійові та сталеві (XC100) поверхні шляхом реактивного радіочастотного магнетронного двокатодного розпорошення цілей із різним вмістом Мо та V із використанням азоту в якості реакційноздатного газу. Відхили напруги зміщення металевої цілі варіювалися від 300 до 900 В. Твердість, морфологію поверхні, мікроструктуру та склад було досліджено за допомогою метод наноіндентування, сканувальної електронної мікроскопії, атомно-силової мікроскопії та рентґенівської дифрактометрії. Плівки Mo–V–N мають пірамідальну морфологію поверхні, високу шерсткість (13,5 нм), але низькі механічні властивості. Твердість і модуль Юнґа лежать у діяпазонах 10–18 ГПа та 100–335 ГПа відповідно. Залишкові напруження у покриттях (обчислені за формулою Стоні) є стискальними і лежать у межах між 0,8 і 2,5 ГПа

Effect of Heat Treatments on the Mechanical Properties of a Form Tool

During the follow-up of the cutting tools in the production workshops, we noticed that the cutting tools operate in severe conditions, for this we thought to improve their mechanical characteristics and increase their yield. Two key factors influencing these tools, namely geometry and heat treatment. In this study we chose the heat treatment, from a basic fast steel form tool, after making the milling cutter in the tool shop we proceeded to a revenue treatment to remove austenite residues. The purpose of our work is to increase the machining quota of a Z80WCV 18-04-01 high speed steel mill, for this reason our study is based on the reduction of residual austenite by incomes. cumulated after prior quenching for different austenitization temperatures (1240, 1260 and 1270 °C)

Characterization of Precipitates in the 18-1-1 and 18-1-1-5 High-Speed Steels During Tempering After Previous Quenching

In this paper the precipitates formed during the tempering after quenching (in salt bath) at temperature 1240 °C for 18-1-1 and 18-1-1-5 high-speed steels are investigated using an analytical transmission electron microscope (A-TEM). The study of this tempering is carried out in isothermal and anisothermal conditions, by comparing the results given by dilatometry and hardness. Tempering is performed in the range of 350-750 °C. Coarse primary carbides retained after heat treatment are of the V-rich MC and W-V-rich M6C types. In turn, it gives a significant influence on the precipitation of dispersive secondary carbides (M4C3 type), that is secondary hardening during tempering. The hardness peak is observed in the tempering range of 500-550 °C (66.8 HRC after a double tempering at 550 °C). It was found out that the cobalt in the concentration limited to about 5 % results in increasing the effect of the secondary hardening by 2 HRC. Between 700 and 750 °C, the impoverished phase (retained austenite) transforms on heating. In the end, in this temperature range of tempering, other more stable carbides of the M6C and M23C6 types are formed developing at the expense of the carbides M4C3 and M7C3 formed before, which then disappear

Mechanical and Structural Studies of Ternary Mo–Zr–N Layers Deposited on Substrate by PVD

Our study of ternary Mo–Zr–N thin layers is novel with the objective of improving certain mechanical and tribological characteristics and of finding the appropriate stoichiometry to have the microstructure, which orientates to the desired properties, using the characterization techniques: SEM, XRD, EDS, XPS, WDS and similar methods as well as nanoindentation, alternative tribometry and scratch test.Целью данной работы является совершенствование механических характеристик трёхкомпонентных покрытий, изготовленных из нитрида молибдена–циркония (Mo–Zr–N), а также нахождение соответствующей стехиометрии, ориентированной на желаемые свойства, с использованием следующих методов характеризации: SEM, XRD, EDS, XPS, WDS и др., а также наноиндентирования, альтернативной трибометрии и испытаний с помощью нанесения царапин.Метою даної роботи є поліпшення механічних характеристик трикомпонентних покриттів з нітриду молібден–цирконію (Mo–Zr–N), а також пошук відповідної стехіометрії, щоб одержати мікроструктуру, орієнтовану на очікувані властивості, з використанням наступних метод характеризації: SEM, XRD, EDS, XPS, WDS та ін., а також наноіндентування, альтернативної трибометрії та випробувань за допомогою нанесення подряпин

Influence of vanadium on structure,

This work aims to show the characterisation of Cr–V–N coatings, with the varied amounts of Cr and V. CrN, VN and Cr–V–N coatings were deposited onto silicon and XC100 steel substrates by reactive radio frequency magnetron sputtering and characterised with X-ray diffraction, X-ray photoelectron spectroscopies, energy dispersive X-ray spectroscopy, scanning electron microscopy, nanoindentation, pin on disc tribological tests and scratch tests. The residual stress was calculated using the Stoney formula. Compared to the CrN system, the Cr–V–N films presented a rough surface based on pyramidal morphology. A hardness of 19?53 GPa and a friction coefficient of 0?55 were obtained for CrN; in contrast, Cr–V–N coatings presented a weak hardness of 6?23 GPa. In the case of wear against a 100Cr6 ball, the Cr–V–N films were completely removed from the substrate, even though the Cr–V–N coating presented a low friction coefficient (0?39). However, the VN film showed good tribological performance.Ministère algérie

Influence of the carburization time on the structural and mechanical properties of XC20 steel

This study focuses on the effect of carburization time on the structural and mechanical properties of low carbon XC20 mild steel (C. Wt.% <0.25). The XC20 steel was carburized with activated carbon with a carbon potential Cp1 = 1.1%, at 910 C at different carburization times of 2, 4 and 6 h. The results obtained show that XC20 steel (non-carburized) has a ferrite-pearlitic structure with a hardness and a Young's modulus of the order of (150 HV, 26 KN/mm2). After carburization, the structure of the carburized layer is transformed in martensite (Fe γ) in which cementite (Fe3C) is imbricated. The depth of the carburized layer and the amount of carbon on the surface gradually increase with increasing carburization time. In addition, the carburized XC20 steel becomes hard and brittle where the hardness and Young's modulus have been increased for a high holding time until reaching maximum values (845 HV, 48 KN mm-2) after 6 h of carburization . However, the toughness of XC20 steel has been reduced from 163 to 40 J cm-2

Effect of Zr content on friction and wear behavior of Cr‐Zr‐N coating system

Nanostructured Cr‐Zr‐N thin film with different Zr content (0 to 48.8 at.%) was deposited, using an RF magnetron‐sputtering technique. The structural evolution and morphological changes were performed. The tribological performances were evaluated, using a ball‐on‐disk type Oscillating tribometer. The tests were carried out under normal loads of 2, 4 and 6 N, respectively, with an alumina ball (Al2O3) as a counter face. The results showed that the crystallite size of the Cr‐Zr‐N system was reduced to 10.8 nm at 31.8 at.% Zr content. Morphological studies of the films showed that the roughness continuously decreased with increasing Zr content, exhibiting a value of 11.2 nm at 31.8 at.% Zr. The wear rate tends to decrease with the increasing of Zr content to reach a lowest value of 1.95 × 10‐2 μm3.N.μm‐1 at 31.8 at.% Zr. The wear rate and friction coefficient were lower in the samples with 31.8 at.% Zr content. The improved friction and wear resistance were attributed to the grain refinement strengthening mechanism at 31.8 at.% of Zr

Thermal treatment effect on structural and mechanical properties of Cr–C coatings

In the present study, the effect of thermal treatment on the mechanical and structural properties of chromium carbide coatings with different thicknesses is evaluated. The coatings were deposited by cathodic magnetron sputtering on XC100 steel substrates. Samples were annealed in vacuum, at different temperatures ranging from 700 to 1000°C for 1 h, resulting in the formation of chromium carbides. X-ray diffraction (XRD), microanalysis X/energy-dispersive X-ray spectrometer (EDS), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy analysis were used to characterise the samples. Mechanical properties were evaluated by nano-indentation tests and the residual stress was calculated with the Stoney formula. The XRD analysis suggests the formation of the Cr7C3, Cr23C6 carbides at 900°C. For thin films, they transformed totally to ternary (Cr, Fe)7C3 carbides and their partial transformation has been observed in the case of thick films at 1000°C, without the formation of Cr3C2. The EDS and XPS showed the diffusion mechanism between the chromium film and the steel substrate for the Cr, Fe, C, O elements during the annealing treatment. The increase of chromium film thickness from 0.5 to 2.64 μm, contributed to the significant enhancement of mechanical properties such as hardness (H) (from 12 to 26.3 GPa) and Young’s Modulus (E) (from 250 to 330 GPa), respectively

Influence d'une addition de vanadium sur le comportement structural et mecanique d'aciers du type Z 90 CDS 8.2.2. pour cylindre de laminoir a chaud

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

One dimensional modeling of the thermoelastic behavior of shape memory alloys

Many facets of the behavior of shape memory alloys have enormously attracted scientists and researchers, studying and modeling their behavior are still problematic. It is in this context that several models have been developed using a lot of approaches ranging from microscopic to macroscopic scale. In this paper we have considered the superthermal effect (thermoelastic) of shape memory alloys and we have adopted a macroscopic approach. The model takes in account only macroscopic observations, it was built basing on thermodynamic laws of thermodynamics and simple assumptions in order to simplify as much as possible its use in engineering without losing accuracy. To validate the model, we have simulated numerically the response and compared it to experimental data