scholarly journals Mechanical Properties and Thermal Stability of TiN/Ta Multilayer Film Deposited by Ion Beam Assisted Deposition

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Hongfei Shang ◽  
Jian Li ◽  
Tianmin Shao

TiN/Ta multilayer film with a modulation period of 5.6 nm and modulation ratio of 1 : 1 was produced by ion beam assisted deposition. Microstructure of the as-deposited TiN/Ta multilayer film was observed by transmission electron microscopy and mechanical properties were investigated. Residual stress in the TiN/Ta multilayer film was about 72% of that of a TiN monolayer film with equivalent thickness deposited under the same conditions. Partial residual stress was released in the Ta sublayers during deposition, which led to the decrease of the residual stress of the TiN/Ta multilayer film. Nanohardness (H) of the TiN/Ta multilayer film was 24 GPa, 14% higher than that of the TiN monolayer film. It is suggested that the increase of the nanohardness is due to the introduction of the Ta layers which restrained the growth of TiN crystal and led to the decrease of the grain size. A significant increase (3.5 times) of theH3/E2(Eelastic modulus) value indicated that the TiN/Ta multilayer film has higher elasticity than the TiN monolayer film. TheLc(critical load in nano-scratch test) value of the TiN monolayer film was 45 mN, which was far lower than that of the TiN/Ta multilayer film (around 75 mN). Results of the indentation test showed a higher fracture toughness of the TiN/Ta multilayer film than that of the TiN monolayer film. Results of differential scanning calorimetric (DSC) and thermo gravimetric analysis (TGA) indicate that the TiN/Ta multilayer film has better thermal stability than the TiN monolayer film.

2000 ◽  
Vol 18 (4) ◽  
pp. 1567-1570 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Nobuaki Kitazawa ◽  
Yoshikazu Nakamura ◽  
Chunliang Li ◽  
Tohru Sekino ◽  
...  

2021 ◽  
pp. 002199832199910
Author(s):  
Y Ben Smail ◽  
A El Moumen ◽  
A Imad ◽  
F Lmai ◽  
M Ezahri

In the last two decades, an increasing interest has been observed for the use of natural fibers such as jute fibers in different applications. These fibers are characterized by their low cost and their availability. They are mainly used in fabric bag manufacturing. The objective of this paper is to study the effect of temperature on the mechanical properties of jute yarns. An experimental study was conducted at different temperatures (22 °C; 80 °C; 105 °C and 150 °C) for 24 h. Each degree was followed by tensile testing of the specimen. Besides, the thermo-gravimetric analysis (TGA) was used to investigate the effect of the temperature on the thermal stability and the thermal degradation of the jute fibers. In addition, the statistical analysis was performed using the method of two and three-parameter Weibull distribution to determine the spatial distribution of the properties. The results showed that there was a degradation of the mechanical properties of the jute yarns heated to high temperature compared to the raw yarns (considered as a specimen exposed to 22 °C). The tensile strain and the Young modulus failed by 36% and 13% respectively for the specimens heated at 150 °C and the failure kinematic of the jute fiber was affected by the temperature of heating. The TGA showed that the thermal stability of the jute yarns was affected by two factors: fibers drying and their changing temperatures.


2014 ◽  
Vol 6 (2) ◽  
pp. 1122-1134 ◽  
Author(s):  
Mokhtar Hemdan Abd El-Salam

Due to the light weight, high specific strength and non hazardous nature of bamboo fiber, it is preferred over synthetic fibers in composite materials for a wide range of applications such as automotive industry and including household sectors. As was noticed, little attention has been given to the effect of bamboo powder on the mechanical properties of rubber composites. Hence, an attempt has been made in this paper to the study the effect of loading and particle size of bamboo powder on the mechanical properties of EPDM composites. Thermo-gravimetric analysis (TGA) was carried out to study the thermal stability of composites. Results indicated that the thermal stability of EPDM was further improved with increasing in bamboo loading and decreasing in particle size. The stress- strain curves of the composites were studied and fitted according toOgden’s model. Mechanical parameters for the studied composites were improved with increasing bamboo loading. Besides, properties such as rupture stress, and internal friction were found to be maximum for composites containing certain content of bamboo powder, depending upon its particle size. Moreover, composites containing the smallest particle size of powder, at all levels of bamboo loading, showed mechanical properties superior to all other composites. From the dynamic mechanical measurements, the dynamic modulus, internal friction, and thermal diffusivity were calculated. The observed variations were explained in view of the role played by both the loading level and the particle size of bamboo powder. These findings were supported by scanning electron microscopy (SEM) micrographs.


2000 ◽  
Vol 647 ◽  
Author(s):  
Shuichi Miyabe ◽  
Toshiyuki Okawa ◽  
Nobuaki Kitazawa ◽  
Yoshihisa Watanabe ◽  
Yoshikazu Nakamura

AbstractAluminum nitride (AlN) thin films were prepared by ion-beam assisted deposition method, and the influence of the nitrogen ion beam energy on their microstructure and mechanical properties was studied by changing the ion beam energy from 0.1 to 1.5 keV. Films prepared with a low-energy ion beam show a columnar structure, while films prepared with a high-energy ion beam show a granular structure. The film hardness is found to decrease with increasing nitrogen ion beam energy. It is also found that the film hardness does not change drastically after annealing in nitrogen atmosphere at 500 °C, yielding the residual stress relaxation. It is proposed that the film hardness is dependent on the film microstructure, which can be controlled with the nitrogen ion beam energy, rather than the residual stress in the films.


1999 ◽  
Vol 17 (2) ◽  
pp. 603-607 ◽  
Author(s):  
Yoshihisa Watanabe ◽  
Shingo Uchiyama ◽  
Yoshikazu Nakamura ◽  
Chunlang Li ◽  
Tohru Sekino ◽  
...  

2010 ◽  
Vol 24 (01n02) ◽  
pp. 43-50 ◽  
Author(s):  
L. DONG ◽  
G. Q. LIU ◽  
Y. D. SUN ◽  
M. Y. LIU ◽  
D. J. LI

TiB 2/ Si 3 N 4 nano multilayers have been synthesized under different deposition parameters related to substrate by ion beam assisted deposition (IBAD). XRD, Nano indenter, profiler, and multi-functional tester for material surface properties were used to characterize the microstructure and mechanical properties of the multilayers. The results indicated a well-defined composition modulation and layer structure of the multilayers. To the multilayers with constant modulation ratio of 15.4:1 and modulation period of 11.8 nm, the multilayer deposited on Al 2 O 3(111) substrate with 38 nm-thick Ti buffer layer at deposition temperature of 225°C revealed the highest hardness (37.4 GPa) and elastic modulus. This hardest multilayer also showed the improved residual stress, friction coefficient, and fracture resistance.


2010 ◽  
Vol 139-141 ◽  
pp. 129-132
Author(s):  
Dong Fang Li ◽  
Li Li ◽  
Jian Zhang Li

Wood plastic composite (WPC) is very useful new material in the modern society. Improving the interfacial bond strength between wood and plastic is the foundation of improving the properties of WPC. Ethylene vinyl acetate (EVA) was used as the coupling agent of WPC in this study. Thermo-gravimetric analysis (TGA) was employed to study the thermal stability of wood flour modified by EVA. The modulus of rupture (MOR), the modulus of elasticity (MOE), and the tensile strength of WPC were investigated to understand the effects of the vinyl acetate (VA) content and the melt index of EVA on WPC. The results show that EVA could improve the thermal stability of wood flour and the mechanical properties of WPC. The mechanical properties of WPC are increasing with VA content raise and melt index reducing.


1996 ◽  
Vol 434 ◽  
Author(s):  
H. Ji ◽  
G. S. Was ◽  
J. W. Jones

AbstractMechanical properties of niobium thin films are studied by controlling the microstructure, texture and residual stress of the films using ion beam assisted deposition (IBAD). Niobium films were deposited onto (100) Si substrates and their microstructure, texture and residual stress were measured as a function of ion energy and R ratio (ion to atom arrival rate ratio). The grain sizes of these films ranged from 20 nm to 40 nm and no effect of ion bombardment was observed. All the films have strong (110) fiber texture, but the in-plane texture is a strong function of the incident angle, energy and flux of the ion beam. Results show that while the degree of the texture increases with increasing ion energy and flux, it is also a strong linear function of the product of the two. The residual stress of the films was measured by a scanninglaser reflection technique. As a function of normalized energy, the stress is tensile for En < 30 eV/atom with a maximum of 400 MPa at about 15 eV/atom. It becomes compressive with increasing normalized energy and saturates at - 400 MPa for En > 50 eV/atom. Both PVD (physical vapor deposition) and IBAD films have a hardness of about 6 GPa at shallow depth measured by nanoindentation. The different stress state may be responsible for the 15%difference on hardness observed between the PVD and IBAD films.


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