Catechol-modified polymers for surface engineering of energetic crystals with reduced sensitivity and enhanced mechanical performance

2021 ◽  
pp. 151448
Author(s):  
Zijian Li ◽  
Xu Zhao ◽  
Feiyan Gong ◽  
Congmei Lin ◽  
Yu Liu ◽  
...  
Keyword(s):  
Surface Engineering ◽  
Mechanical Performance ◽  
Modified Polymers

Surface Engineering of the Hydrogenated DLC (a-C:H) Coatings with Optimized Mechanical Performance

2013 ◽  
Vol 816-817 ◽  
pp. 33-37
Author(s):  
Mirela Contulov ◽  
Rodica Vladoiu ◽  
Aurelia Mandes ◽  
Victor Ciupina ◽  
Vilma Buršíková
Keyword(s):  
Mechanical Properties ◽  
Surface Engineering ◽  
Mechanical Performance ◽  
Vacuum Arc ◽  
Deposition Technique ◽  
Depth Sensing ◽  
Cross Sectional ◽  
Thermionic Vacuum Arc

The aim of this contribution is to present the properties of the hydrogenated DLC (a-C:H) films and to study their growth carried out in a special deposition technique based on Gaseous Thermionic Vacuum Arc (G-TVA) method. The mechanical properties were investigated on cross-sectional samples using the Fischerscope HM 2000 depth sensing indentation (DSI) tester.

scholarly journals Fully Flexible, Polymer based Microwave Devices Part II: Flexible Antennas and Performance Evaluation

2021 ◽  
Author(s):  
Iurii Cherukhin
Keyword(s):  
Mechanical Performance ◽  
Dielectric Materials ◽  
Low Loss ◽  
Performance Improvements ◽  
Flexible Polymer ◽  
Modified Polymers ◽  
Flexible Antennas ◽  
And Performance ◽  
Fringing Fields ◽  
Bow Tie

In this work, we have investigated polymer-based flexible antennas from commercial and modified polymers, which are competitive to rigid PCB technology. Classical designs of the patch and bow-tie antennas have been realized and showed that the realized gain can get up to 9.16dBi for the patch and 7.9dBi for the bow-tie antennas. The effects of the dielectric loss and conductivity on the antennas’ performance in S-band have been analyzed in order to find limits for further material engineering and the optimum trade-off between microwave and mechanical performance. The bending effects have been investigated, and it has been found that E-plane bend inside can boost the antenna gain from 8.6dBi to 10.1dBi with the frequency shift from 2.5 GHz to 2.4 GHz for the patch and 7.9dBi to 11.3dBi at 3.1 GHz for the bow-tie antennas. The non-classical π-shaped conductors’ edges lead to additional fringing fields, which have an effect on the antenna’s gain and can be explored and exploited for further performance improvements. The new recipes for low-loss, low-Dk dielectric materials, and chemical integration between conducting

scholarly journals Fully Flexible, Polymer based Microwave Devices Part II: Flexible Antennas and Performance Evaluation

2021 ◽  
Author(s):  
Iurii Cherukhin
Keyword(s):  
Mechanical Performance ◽  
Dielectric Materials ◽  
Low Loss ◽  
Performance Improvements ◽  
Flexible Polymer ◽  
Modified Polymers ◽  
Flexible Antennas ◽  
And Performance ◽  
Fringing Fields ◽  
Bow Tie

In this work, we have investigated polymer-based flexible antennas from commercial and modified polymers, which are competitive to rigid PCB technology. Classical designs of the patch and bow-tie antennas have been realized and showed that the realized gain can get up to 9.16dBi for the patch and 7.9dBi for the bow-tie antennas. The effects of the dielectric loss and conductivity on the antennas’ performance in S-band have been analyzed in order to find limits for further material engineering and the optimum trade-off between microwave and mechanical performance. The bending effects have been investigated, and it has been found that E-plane bend inside can boost the antenna gain from 8.6dBi to 10.1dBi with the frequency shift from 2.5 GHz to 2.4 GHz for the patch and 7.9dBi to 11.3dBi at 3.1 GHz for the bow-tie antennas. The non-classical π-shaped conductors’ edges lead to additional fringing fields, which have an effect on the antenna’s gain and can be explored and exploited for further performance improvements. The new recipes for low-loss, low-Dk dielectric materials, and chemical integration between conducting

The Mechanical Performance of Carbon Fibres- Addressing the Role of Microstructure

2019 ◽  
Author(s):  
Peter Peter ◽  
Claudia Creighton ◽  
David Fox ◽  
Pablo Mota Santiago ◽  
Adrian Hawley ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Carbon Fibres

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

Surface engineering casebook

1996 ◽  
Author(s):  
J S Burnell-Gray ◽  
P K Datta
Keyword(s):  
Surface Engineering
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