scholarly journals Effects of Nitrogen Flow Ratio on Structures, Bonding Characteristics, and Mechanical Properties of ZrNx Films

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 476 ◽  
Author(s):  
Yi-En Ke ◽  
Yung-I Chen

ZrNx (x = 0.67–1.38) films were fabricated through direct current magnetron sputtering by a varying nitrogen flow ratio [N2/(Ar + N2)] ranging from 0.4 to 1.0. The structural variation, bonding characteristics, and mechanical properties of the ZrNx films were investigated. The results indicated that the structure of the films prepared using a nitrogen flow ratio of 0.4 exhibited a crystalline cubic ZrN phase. The phase gradually changed to a mixture of crystalline ZrN and orthorhombic Zr3N4 followed by a Zr3N4 dominant phase as the N2 flow ratio increased up to >0.5 and >0.85, respectively. The bonding characteristics of the ZrNx films comprising Zr–N bonds of ZrN and Zr3N4 compounds were examined by X-ray photoelectron spectroscopy and were well correlated with the structural variation. With the formation of orthorhombic Zr3N4, the nanoindentation hardness and Young’s modulus levels of the ZrNx (x = 0.92–1.38) films exhibited insignificant variations ranging from 18.3 to 19.0 GPa and from 210 to 234 GPa, respectively.

Coatings ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 10 ◽  
Author(s):  
Young Seok Kim ◽  
Hae Jin Park ◽  
Ki Seong Lim ◽  
Sung Hwan Hong ◽  
Ki Buem Kim

In the present study, novel AlCoCrNi high entropy nitride (HEN) films were deposited on Si substrate by a reactive direct current magnetron sputtering system. In order to investigate the influence of sputtering parameters on the microstructure and mechanical properties of the film, nitrogen flow ratio (RN: 25–100%) and process pressure (1.33 × 10−1–1.33 Pa) were controlled, respectively. All the films were identified as an amorphous phase with composition of near equiatomic ratios, regardless of the conditions of nitrogen flow ratios and process pressures. However, the limited mechanical properties were found for the films deposited under different nitrogen flow ratios with retaining the process pressure of 1.33 Pa. To enhance the mechanical properties of the AlCoCrNi HEN film, process pressure was adjusted. From the transmission electron microscopy (TEM) observation, the structure of the film deposited at the process pressure of 1.33 Pa is identified as a porous and open structure with a number of density-deficient boundary and nano-scale voids. On the other hand, densified morphology of the film was observed at pressure of 1.33 × 10−1 Pa. As a result, the hardness, elastic modulus, and H/E were improved up to 16.8, 243 GPa, and 0.0692, respectively.


Coatings ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1252
Author(s):  
Li-Chun Chang ◽  
Ming-Ching Sung ◽  
Li-Heng Chu ◽  
Yung-I Chen

The reactive gas flow ratio and substrate bias voltage are crucial sputtering parameters for fabricating transition metal nitride films. In this study, W–N films were prepared using sputtering with nitrogen flow ratios (f) of 0.1–0.5. W–N and W–Si–N films were then prepared using an f level of 0.4 and substrate bias varying from 0 to −150 V by using sputtering and co-sputtering, respectively. The variations in phase structures, bonding characteristics, mechanical properties, and wear resistance of the W–N and W–Si–N films were investigated. The W–N films prepared with nitrogen flow ratios of 0.1–0.2, 0.3, and 0.4–0.5 displayed crystalline W, amorphous W–N, and crystalline W2N, respectively. The W–N films prepared using a nitrogen flow ratio of 0.4 and substrate bias voltages of −50 and −100 V exhibited favorable mechanical properties and high wear resistance. The mechanical properties of the amorphous W–Si–N films were not related to the magnitude of the substrate bias.


2020 ◽  
Author(s):  
Sahar. Mokhtari ◽  
Anthony.W. Wren

AbstractThis study addresses issues with currently used bone adhesives, by producing novel glass based skeletal adhesives through modification of the base glass composition to include copper (Cu) and by characterizing each glass with respect to structural changes. Bioactive glasses have found applications in fields such as orthopedics and dentistry, where they have been utilized for the restoration of bone and teeth. The present work outlines the formation of flexible organic-inorganic polyacrylic acid (PAA) – glass hybrids, commercial forms are known as glass ionomer cements (GICs). Initial stages of this research will involve characterization of the Cu-glasses, significant to evaluate the properties of the resulting adhesives. Scanning electron microscopy (SEM) of annealed Cu glasses indicates the presence of partial crystallization in the glass. The structural analysis of the glass using Raman suggests the formation of CuO nanocrystals on the surface. X-ray diffraction (XRD) pattern and X-ray photoelectron spectroscopy (XPS) further confirmed the formation of crystalline CuO phases on the surface of the annealed Cu-glass. The setting reaction was studied using Fourier transform infrared spectroscopy (ATR-FTIR). The mechanical properties of the Cu containing adhesives exhibited gel viscoelastic behavior and enhanced mechanical properties when compared to the control composition. Compression data indicated the Cu glass adhesives were efficient at energy dissipation due to the reversible interactions between CuO nano particles and PAA polymer chains.


2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Anna Majtyka ◽  
Anna Nowak ◽  
Benoît Marchand ◽  
Dariusz Chrobak ◽  
Mikko Ritala ◽  
...  

The present paper pertains to mechanical properties and structure of nanocrystalline multiferroic BeFiO3(BFO) thin films, grown by atomic layer deposition (ALD) on the Si/SiO2/Pt substrate. The usage of sharp-tip-nanoindentation and multiple techniques of structure examination, namely, grazing incidence X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectrometry, enabled us to detect changes in elastic properties(95 GPa≤E≤118 GPa)and hardness(4.50 GPa≤H≤7.96 GPa)of BFO after stages of annealing and observe their relation to the material’s structural evolution. Our experiments point towards an increase in structural homogeneity of the samples annealed for a longer time. To our best knowledge, the present report constitutes the first disclosure of nanoindentation mechanical characteristics of ALD-fabricated BeFiO3, providing a new insight into the phenomena that accompany structure formation and development of nanocrystalline multiferroics. We believe that our systematic characterization of the BFO layers carried out at consecutive stages of their deposition provides pertinent information which is needed to control and optimize its ALD fabrication.


Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 427 ◽  
Author(s):  
Jie Jin ◽  
Wei Wang ◽  
Xinchun Chen

In this study, Ti + N ion implantation was used as a surface modification method for surface hardening and friction-reducing properties of Cronidur30 bearing steel. The structural modification and newly-formed ceramic phases induced by the ion implantation processes were investigated by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and grazing incidence X-ray diffraction (GIXRD). The mechanical properties of the samples were tested by nanoindentation and friction experiments. The surface nanohardness was also improved significantly, changing from ~10.5 GPa (pristine substrate) to ~14.2 GPa (Ti + N implanted sample). The friction coefficient of Ti + N ion implanted samples was greatly reduced before failure, which is less than one third of pristine samples. Furthermore, the TEM analyses confirmed a trilamellar structure at the near-surface region, in which amorphous/ceramic nanocrystalline phases were embedded into the implanted layers. The combined structural modification and hardening ceramic phases played a crucial role in improving surface properties, and the variations in these two factors determined the differences in the mechanical properties of the samples.


2002 ◽  
Vol 17 (6) ◽  
pp. 1390-1398 ◽  
Author(s):  
A. R. Phani ◽  
J. E. Krzanowski ◽  
J. J. Nainaparampil

Multilayers of TiC/Ti and TiC/B4C have been deposited by pulsed laser deposition. Ti, B4C, and TiC targets were used to deposit multilayer films onto 440C steel and silicon substrates at 40 °C. The structural, compositional, and mechanical properties of the multilayers were examined by x-ray diffraction, x-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation techniques. Tribological properties were also evaluated using a pin-on-disc friction and wear test. The TiC/Ti films were found to have a crystalline structure, and both (200)TiC/(100)Ti and (111)TiC/(101)Ti orientation relationships were found in these films. In the TiC/B4C films, only the sample with the largest bilayer thickness (25 nm) had significant crystallinity and only the TiC layer was crystalline. X-ray photoelectron spectroscopy depth profiles confirmed the presence of composition modulations in these films. Nanoindentation tests of the TiC/Ti multilayers showed hardness levels exceeding that predicted by the rule-of-mixtures. The TiC/B4C multilayers showed increasing hardness with decreasing bilayer thickness but reached only 22 GPa. The pin-on-disc tests gave friction values ranging from 0.3 to 0.9 for both sets of films. These results were correlated with the degree of crystallinity and grain structure of the films.


2007 ◽  
Vol 539-543 ◽  
pp. 173-180 ◽  
Author(s):  
In Wook Park ◽  
Brajendra Mishra ◽  
Kwang Ho Kim ◽  
John J. Moore

Ti–B–C–N and Ti–Si–B–C–N nanocomposite coatings were deposited on AISI 304 stainless steel substrates by DC unbalanced magnetron sputtering from two (80mol% TiB2–20mol% TiC and 40mol% TiB2–60mol% TiC) composite targets in various Si target powers. The relationship among microstructures, mechanical properties, and tribologiacal properties was investigated. The synthesized Ti–B–C–N and Ti–Si–B–C–N coatings were characterized using x–ray diffraction (XRD) and x–ray photoelectron spectroscopy (XPS). These analyses revealed that the Ti–Si–B–C–N coatings are nanocomposites consisting of solid-solution (Ti,C,N)B2 and Ti(C,N) crystallites distributed in an amorphous TiSi2, SiC, and SiB4 matrix including some carbon, BN, CNx, TiO2, and B2O3 components. The addition of Si to the Ti–B–C–N coating led to percolation of amorphous TiSi2, SiC, and SiB4 phases. The Ti–Si–B–C–N coatings exhibited high hardness and H/E values, indicating high fracture toughness, of approximately 35 GPa and 0.098, respectively. Furthermore, the Ti–Si–B–C–N coatings exhibited very low wear rates ranging from ~3×10-7 to ~16×10-7 mm3/(N·m). The minimum friction coefficient of the Ti–Si–B–C–N coatings was approximately 0.15 at low Si target power between 25W and 50W. A systematic investigation on the microstructures, mechanical properties, and tribological properties of Ti–Si–B–C–N coatings prepared from two TiB2–TiC composite targets and one Si target is reported in this paper.


2005 ◽  
Vol 475-479 ◽  
pp. 3595-3598
Author(s):  
Lan Zhang ◽  
Hui Zhong Ma ◽  
Xue Xiang Li ◽  
Ning Yao ◽  
Bing Lin Zhang

Carbon nitride nanotubes (CN-NT) thin films were prepared on Ni-Cr coated glass substrate by microwave plasma enhanced chemical vapor deposition at a relatively low temperature of 600~650 °C. The morphology of the films were observed by scanning electron microscopy. The microstructure of the film were analyzed by x-ray photoelectron spectroscopy, x-ray diffraction, and Raman spectroscopy. The characteristics of field emission of CN-NT thin films were measured. Experimental results indicate that the film structure and properties of the field electron emission are related to flow ratio of N2 to CH4. When the flow ratio of N2 to CH4 was 3.3, the obtained film had a better field electron emission characteristics. The turn-on field of the film was 3.7 V/µm . The current density was 413.3 µA/cm2 at an electric field of 8 V/µm.


2001 ◽  
Vol 16 (11) ◽  
pp. 3188-3201 ◽  
Author(s):  
Niklas Hellgren ◽  
Nian Lin ◽  
Esteban Broitman ◽  
Virginie Serin ◽  
Stefano E. Grillo ◽  
...  

The thermal stability of carbon nitride films, deposited by reactive direct current magnetron sputtering in N2 discharge, was studied for postdeposition annealing temperatures TA up to 1000 °C. Films were grown at temperatures of 100 °C (amorphous structure) and 350 and 550 °C (fullerenelike structure) and were analyzed with respect to thickness, composition, microstructure, bonding structure, and mechanical properties as a function of TA and annealing time. All properties investigated were found to be stable for annealing up to 300 °C for long times (>48 h). For higher TA, nitrogen is lost from the films and graphitization takes place. At TA = 500 °C the graphitization process takes up to 48 h while at TA = 900 °C it takes less than 2 min. A comparison on the evolution of x-ray photoelectron spectroscopy, electron energy loss spectroscopy and Raman spectra during annealing shows that for TA > 800 °C, preferentially pyridinelike N and –C≡N is lost from the films, mainly in the form of molecular N2 and C2N2, while N substituted in graphite is preserved the longest in the structure. Films deposited at the higher temperature exhibit better thermal stability, but annealing at temperatures a few hundred degrees Celsius above the deposition temperature for long times is always detrimental for the mechanical properties of the films.


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