Study of nanostructured HfN coatings using layers arrangement

MRS Advances ◽  
2017 ◽  
Vol 2 (49) ◽  
pp. 2775-2780
Author(s):  
L. García González ◽  
S.R. Vásquez García ◽  
D.J. Araujo-Pérez ◽  
A. K. García Rueda ◽  
L. Zamora Peredo ◽  
...  
Keyword(s):  
Hardness Test ◽  
Deposition Process ◽  
Rietveld Analysis ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Nitrogen Gas ◽  
Nanostructured Ceramic ◽  
Number Of Cycles ◽  
Stoney Formula ◽  
Hardness Values

ABSTRACTIn the present investigation, nanostructured ceramic HfN coatings were deposited onto silicon (100) wafer by magnetron sputtering DC method, from a metallic Hf target. The deposition process followed by a similar pattern as the multilayer film deposition, using cycles with the nitrogen gas turned on for 90 s and turned off for 15 s; four sets of samples were obtained using 5, 10, 15 and 20 cycles. The X ray diffraction (XRD) identified the presence of two different cubic crystalline phases of HfN, corroborated by Rietveld analysis. The Vickers hardness test showed that the hardness values increases with more cycles, due to a higher compressive stress evaluated by Stoney formula. All samples were investigated with no visible fracture until 10 grf for the 5 cycles sample; however, no fractures were visible at all for the 15 and 20 cycle samples for that given load, instead fractures started to appear at 25grf for the 10 and 15 cycles coating. Eventually it is distinguished that, the thickness and morphology of the coatings were measured by field emission scanning electron microscopy FE-SEM. As well as, the thickness increased from 0.4 µm to almost 1.33 µm as the number of cycles also increased, where we can observe the formation of columnar growth, moreover it is possible to distinguish the formation of two different clusters which might be related to different phases.

Micro-Hardness and Morphology of LDPE Influenced by Beta Radiation

2014 ◽  
Vol 606 ◽  
pp. 253-256 ◽  
Author(s):  
Martin Ovsik ◽  
Petr Kratky ◽  
David Manas ◽  
Miroslav Manas ◽  
Michal Stanek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Hardness Test ◽  
Polymer Materials ◽  
Beta Radiation ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
Depth Sensing ◽  
Surface Layers ◽  
Hardness Values ◽  
Different Doses

This article deals with the influence of different doses of Beta radiation to the structure and mico-mechanical properties of Low-density polyethylene (LDPE). Hard surface layers of polymer materials, especially LDPE, can be formed by radiation cross-linking by β radiation with doses of 33, 66 and 99 kGy. Material properties created by β radiation are measured by micro-hardness test using the DSI method (Depth Sensing Indentation). Individual radiation doses caused structural and micro-mechanical changes which have a significant effect on the final properties of the LDPE tested. The highest values of micro-mechanical properties were reached at radiation dose of 66 and 99 kGy, when the micro-hardness values increased by about 21%. The changes were examined and confirmed by X-ray diffraction.

scholarly journals Deposition of Zinc Selenide by Atomic Layer Epitaxy for Multilayer X-Ray Optics

1989 ◽  
Vol 161 ◽  
Author(s):  
J.K. Shurtleff ◽  
D.D. Allred ◽  
R.T. Perkins ◽  
J.M. Thorne
Keyword(s):  
Chemical Vapor ◽  
Atomic Layer ◽  
Thin Film Deposition ◽  
Deposition Process ◽  
Film Deposition ◽  
Atomic Layer Epitaxy ◽  
Ray Optics ◽  
X Ray ◽  
Vapor Deposition Technique ◽  
Number Of Cycles

ABSTRACTThin film deposition techniques currently being used to produce multilayer x-ray optics (MXOs) have difficulty producing smooth, uniform multilayers with d-spacings less than about twelve angstroms. We are investigating atomic layer epitaxy (ALE) as an alternative to these techniques.ALE is a chemical vapor deposition technique which deposits an atomic layer of material during each cycle of the deposition process. The thickness of a film deposited by ALE depends only on the number of cycles. Multilayers deposited by ALE should be smooth and uniform with precise d-spacings which makes ALE an excellent technique for producing multilayer x-ray optics.We have designed and built an ALE system and we have used this system to deposit ZnSe using diethyl zinc and hydrogen selenide.

Relationship between Compressive Residual Stress Relaxation and Microhardness Reduction after Cyclic Loads on Shotpeened ASTM A516 Grade 70 Steel

2018 ◽  
Vol 765 ◽  
pp. 232-236 ◽  
Author(s):  
Mohd Rashdan Isa ◽  
Omar Suliman Zaroog ◽  
Fareg S. Ali
Keyword(s):  
Residual Stress ◽  
Yield Strength ◽  
Shot Peening ◽  
Cyclic Load ◽  
Compressive Residual Stress ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
X Ray ◽  
Low Load ◽  
Hardness Values

Shot peening process is a cold performed function to enhance the mechanical properties which is widely used in many industries. This process introduces compressive residual stress which was proven to increase the fatigue life, geometry stability and corrosion resistance. However, the benefit of the residual stress is still unstable due to the relaxation during the operation. This paper will study on the trend of the relaxation of residual stress against cyclic loading as well as the change in the hardness. The material used in this study is carbon steel ASTM A516/ SA 516 Grade 70. Shot peening process with steel shots was applied to the samples to introduce compressive residual stress in the samples. Cyclic load was applied to samples after shot peening process with low load of 52Mpa (20% of Yield Strength) and high load of 208Mpa (80% of Yield Strength). The measurement of residual stress using X-Ray diffraction and hardness test was done on the samples to study the trend of the relaxation of residual stress and the change in hardness values. The result shows that more relaxation of residual stress occurs if the applied cyclic load is higher. The change of hardness trend is found non-sequenced in this study due to random coverage of shot peening.

Self-Assembly Optical Components

2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Optical Components ◽  
Crystal Film ◽  
Solid Film ◽  
Thin Crystal

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.

scholarly journals Preparation of high-entropy carbides by different sintering techniques

2021 ◽  
Vol 56 (19) ◽  
pp. 11237-11247 ◽  
Author(s):  
Johannes Pötschke ◽  
Manisha Dahal ◽  
Mathias Herrmann ◽  
Anne Vornberger ◽  
Björn Matthey ◽  
...  
Keyword(s):  
Grain Size ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Vacuum Sintering ◽  
X Ray ◽  
High Entropy ◽  
Mean Grain Size ◽  
The Mean ◽  
Gas Pressure Sintering ◽  
Hardness Values

AbstractDense (Hf, Ta, Nb, Ti, V)C- and (Ta, Nb, Ti, V, W)C-based high-entropy carbides (HEC) were produced by three different sintering techniques: gas pressure sintering/sinter–HIP at 1900 °C and 100 bar Ar, vacuum sintering at 2250 °C and 0.001 bar as well as SPS/FAST at 2000 °C and 60 MPa pressure. The relative density varied from 97.9 to 100%, with SPS producing 100% dense samples with both compositions. Grain size measurements showed that the substitution of Hf with W leads to an increase in the mean grain size of 5–10 times the size of the (Hf, Ta, Nb, Ti, V,)C samples. Vacuum-sintered samples showed uniform grain size distribution regardless of composition. EDS mapping revealed the formation of a solid solution with no intermetallic phases or element clustering. X-ray diffraction analysis showed the structure of mostly single-phase cubic high-entropy carbides. Hardness measurements revealed that (Hf, Ta, Nb, Ti, V)C samples possess higher hardness values than (Ta, Nb, Ti, V, W)C samples.

scholarly journals Study of Structural, Magnetic, and Mossbauer Properties of Dy2Fe16Ga1−xNbx (0.0 ≤ x ≤ 1.0) Prepared via Arc Melting Process

2021 ◽  
Vol 7 (3) ◽  
pp. 42
Author(s):  
Jiba N. Dahal ◽  
Kalangala Sikkanther Syed Ali ◽  
Sanjay R. Mishra
Keyword(s):  
Isomer Shift ◽  
Cell Volume ◽  
Intermetallic Compounds ◽  
Unit Cell Volume ◽  
Rietveld Analysis ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
X Ray ◽  
Arc Melting ◽  
Nb Content

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th2Fe17 structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy2Fe17. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe3 and NbFe2 secondary phases at x = 1.0. The hyperfine field of Dy2Fe16Ga1−xNbx decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.

Development of Thin Metal Film Deposition Process for the Intravascular Catheter

1999 ◽  
Author(s):  
Seok Chung ◽  
Jun Keun Chang ◽  
Dong Chul Han
Keyword(s):  
Metal Film ◽  
Three Dimensional ◽  
Deposition Process ◽  
Medical Application ◽  
Thin Metal Film ◽  
Film Deposition ◽  
Thin Metal ◽  
Mems Devices ◽  
Sensors And Actuators ◽  
Custom Made

Abstract To make some MF.MS devices such as sensors and actuators be useful in the medical application, it is required to integrate this devices with power or sensor lines and to keep the hole devices biocompatible. Integrating micro machined sensors and actuators with conventional copper lines is incompatible because the thin copper lines are not easy to handle in the mass production. To achieve the compatibility of wiring method between MEMS devices, we developed the thin metal film deposition process that coats micropattered thin copper films on the non silicon-wafer substrate. The process was developed with the custom-made three-dimensional thin film sputter/evaporation system. The system consists of process chamber, two branch chambers, substrate holder unit and linear/rotary motion feedthrough. Thin metal film was deposited on the biocompatible polymer, polyurethane (PellethaneR) and silicone, catheter that is 2 mm in diameter and 1,000 mm in length. We deposited Cr/Cu and Ti/Cu layer and made a comparative study of the deposition processes, sputtering and evaporation. The temperature of both the processes were maintained below 100°C, for the catheter not melting during the processes. To use the films as signal lines connect the signal source to the actuator on the catheter tip, we machined the films into desired patterns with the eximer laser. In this paper, we developed the thin metal film deposition system and processes for the biopolymeric substrate used in the medical MEMS devices.

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