Correlation between thermal properties and aluminum fractions in CrAlN layers deposited by PVD technique

The CrAlN coatings are a good alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on silicon (100) by PVD (Physical vapor deposition) technique from two targets (chromium and aluminum) in a reactive nitrogen atmosphere at aluminum applied negative voltage ( 300, 500, 700 and 900 V). The composition, structural, mechanical and thermal properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and the ‘‘Mirage effect’’ experiments. The X-ray diffraction (XRD) data show that in general CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1) and (2 0 0) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing aluminum proportion the coatings became more compact and denser and their increased correspondingly, showing a maximum hardness of about 36 GPa (30 at% of Al) which is higher than that of CrN. Moreover, the results in this work demonstrate that the variation of aluminum fraction alter the resulting columnar grain morphology and porosity of the coatings. However, the thermal properties are greatly affected by these morphological alterations. The correlation between aluminum fraction in CrAlN coatings and its thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by a decrease of the stitch parameter dimension

Effect of duplex treatments by plasma nitriding and triode sputtering on corrosion behaviour of 32CDV13 low alloy steel

This paper presents corrosion behaviour of duplex treated low alloy steel. Different kinds of samples were tested: non-treated, plasma nitrided, ZrBN-triode sputtered and ZrBN-duplex treated samples. The corrosion behaviour was evaluated by electrochemical techniques (corrosion potential and polarisation resistance evolutions versus immersion time, potentiodynamic curves). The corrosion tests were carried out in neutral aqueous saline solution (NaCl 30 g L−1), naturally aerated. The composition and the structure of layers were determined by EDS and XRD, respectively, while the morphology was observed by SEM. Experimental results showed that the corrosion current density Icorr increased with decreasing white layer thickness in plasma nitrided specimens. The nitrides ε-Fe2 − 3N and γ′-Fe4N present in the white layer are nobler than the substrate but may promote, by galvanic effect, a localised corrosion through open porosity. The duplex treated specimens (nitriding+ZrBN coating) present better corrosion protection and enable to overcome the drawbacks of both techniques, mainly the porosity of the deposited films

MASALAH PSIKOLOGIS TOKOH BECKMANN DALAM DRAMA DRAUßEN VOR DER TÜR: TEORI PSIKOANALISIS FREUD

Penelitian ini bertujuan untuk mendeskripsikan (1) perwatakan tokoh Beckmann dalam drama Draußen vor der Tür Karya Wolfgang Borchert, (2) masalah psikologis yang dialami tokoh Beckmann dalam drama Draußen vor der Tür Karya Wolfgang Borchert, dan (3) upaya tokoh Beckmann untuk menyelesaikan masalah psikologis yang dialaminya dalam drama Draußen vor der Tür Karya Wolfgang Borchert. Penelitian ini menggunakan teori psikoanalisis Sigmund Freud. Pendekatan penelitian ini adalah pendekatan psikologis. Data penelitian ini berupa kata, frasa, dan kalimat dalam drama Draußen vor der Tür Karya Wolfgang Borchert yang mengandung unsur psikologis. Sumber data penelitian ini adalah naskah drama Draußen vor der Tür Karya Wolfgang Borchert, yang diterbitkan oleh Rowohlt Taschenbuch Verlag Hamburg pada tahun 2012. Penelitian ini merupakan jenis penelitian deskriptif kualitatif. Data diperoleh dengan teknik baca dan catat. Keabsahan data penelitian ini adalah validitas semantis dan expert judgement. Reliabilitas yang digunakan adalah reliabilitas intrarater dan interrater. Hasil dari penelitian ini adalah sebagai berikut: (1) perwatakan tokoh Beckmann; (a) ciri fisik, yakni lelaki dewasa, berusia dua puluh lima tahun, tampak tua dan aneh, cacat kaki dan mata, (b) ciri sosial, yakni seorang tentara perang, berpangkat sersan, tunawisma, dan miskin, (c) ciri psikis, yakni pemarah, keras kepala, tidak sopan, tidak percaya diri, pesimistis, dan sensitif. (2) masalah psikologis yang dialami tokoh Beckmann adalah keputusasaan, kekecewaan, ketidakberdayaan, kecemasan, hilangnya kepercayaan, kebencian, merasa bersalah, dan kebimbangan. (3) upaya tokoh Beckmann untuk menyelesaikan masalah psikologis yang dialaminya adalah rasionalisasi, represi, sublimasi, pengalihan (Displacement), fantasi, proyeksi, apatis, dan bunuh diri

Correlation between thermal properties and aluminum fractions in CrAlN layers deposited by PVD technique

The CrAlN coatings are a good alternative to conventional CrN coatings especially for high temperature oxidation-resistance applications. Different CrAlN coatings were deposited on silicon (100) by PVD (Physical vapor deposition) technique from two targets (chromium and aluminum) in a reactive nitrogen atmosphere at aluminum applied negative voltage ( 300, 500, 700 and 900 V). The composition, structural, mechanical and thermal properties of the as-deposited coatings were systematically characterized by energy dispersive analysis of X-rays, X-ray diffraction, nanoindentation, and the ‘‘Mirage effect’’ experiments. The X-ray diffraction (XRD) data show that in general CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1) and (2 0 0) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing aluminum proportion the coatings became more compact and denser and their increased correspondingly, showing a maximum hardness of about 36 GPa (30 at% of Al) which is higher than that of CrN. Moreover, the results in this work demonstrate that the variation of aluminum fraction alter the resulting columnar grain morphology and porosity of the coatings. However, the thermal properties are greatly affected by these morphological alterations. The correlation between aluminum fraction in CrAlN coatings and its thermal properties revealed that the conductivity and the diffusivity are influenced primarily by size and shape distribution of the pores and secondarily by a decrease of the stitch parameter dimension

Temperature measurement inside and near the weld pool during laser welding

The work in this article deals with the measurement of temperature fields inside and near the weld pool during laser welding. The laser source used for this study is a 7.5 kW CO2 laser, and the welded material is a UNS N08904 austenitic stainless steel. The principle behind the actual experimentation is relatively simple: the welding operation is recorded with a charge coupled device camera equipped with infrared filters; after calibrating the camera sensor and image processing, the temperature distribution in the weld pool and near the melted zone is revealed.Regional Council of Burgund

Estimación de la biomasa del cultivo de cebada (Hordeum vulgare L.) mediante teledetección de imágenes multiespectrales

Este estudio explora el potencial de los vehículos aéreos no tripulados (UAV) y el análisis de imágenes multiespectrales para estimar la biomasa del cultivo de cebada en el altiplano boliviano. Utilizando un dron equipado con una cámara multiespectral, se capturaron imágenes de cultivos de cebada, cuya biomasa se estimó mediante el cálculo del índice de vegetación NDVI y la aplicación de una ecuación de regresión polinomial basada en este índice. La metodología probó ser eficiente y precisa, ofreciendo una alternativa no invasiva y costo-efectiva a largo plazo para la investigación agrícola y la toma de decisiones en comparación con los métodos convencionales. Este enfoque, que combina la teledetección con modelos analíticos avanzados, demuestra una fuerte correlación entre el NDVI y la biomasa de la cebada, con un coeficiente de determinación (R2) de 0.94, resaltando la viabilidad de esta tecnología para mejorar el monitoreo agrícola y optimizar la producción de cultivos en regiones con limitaciones climáticas y de recursos. Esta investigación abre nuevas oportunidades en el uso de la teledetección para mejorar la gestión agrícola y optimizar la producción de cultivos, proporcionando a los agricultores una herramienta precisa y eficiente para la toma de decisiones informadas

Hardness and scratch response of PVD multilayer coatings

In the present investigation, novel Cr/CrN, CrN/CrAlN and Cr/CrN/CrAlN multilayered coatings thin films have been developed by dual RF magnetron sputtering. They consist of superposing Cr, CrN and CrAlN layers of 50–500nm thick, up to a total thickness of 0.45–1μm. These coatings were grown on AISI4140 steel samples. The mechanical properties of these coatings were studied by scratch-tests and nano-indentation measurements. The hardness of the films reaches 15.8 GPa for a Cr/CrN multilayered coating sputtered at a bias voltage of -900V. High peak load tests were used to estimate the film adhesion on steel substrates; critical loads (Lc2) of 11N showed weak adhesion properties of the film. Moreover, an inventory of the major scratch-tests failure modes was established, which were classified into plastic deformation and different forms of cracking, spallation and coating perforation events. No evidence of interfacial failure(s) of the sub-layers was observed after the adhesion and nanoindentation tests