scholarly journals Fabrication and Characterization of Friction Stir-Processed Mg-Zn-Ca Biomaterials Strengthened with MgO Particles

2021 ◽  
Author(s):  
Zhen Liu ◽  
Yangchuan Cai ◽  
Jie Chen ◽  
Jian Han ◽  
Zhiyong Mao ◽  
...  
Keyword(s):  
Grain Refinement ◽  
Performance Test ◽  
Rotational Velocity ◽  
Casting Process ◽  
Test Methods ◽  
The Novel ◽  
Friction Stir ◽  
And Performance ◽  
Particle Strengthening

Abstract Magnesium alloy composites play an important role in biomaterials field. In this study, a novel Mg-Zn-Ca matrix composite was reinforced by adding 1.0 wt.% MgO nanoparticles via the high shear casting process. Hereafter, friction stir processing (FSP) was used to achieve a good dispersion of MgO particles and improve the mechanical properties of the composites. After the preparation of the novel composite materials, varied characterization and performance test methods have been selected for comparison. The results illustrate that through FSP, the corresponding microstructure and properties of as-cast MgO/Mg-Zn-Ca composites were significantly modified, and the best combination of the key parameters is 1200 rpm and 60 mm/min for rotational velocity and traveling speed, respectively. After the optimized FSP treatment, the grains size in FSP-processed composites were refined by 42%, to reach 1.04 μm. Due to the grain refinement and the redistribution of MgO particles, the hardness of the FSP-processed MgO/Mg-Zn-Ca composites were increased by 40%, to reach 101.2 HV. Further, it displayed excellent corrosion resistance as well as strength. Compared to the strengthening through grain refinement, the particle strengthening is more dominant based on the study. And meanwhile, the modified grains and added MgO particles are beneficial to the properties of the nugget zones.

scholarly journals Development and Characterization of a Novel Porous-Media Borosilicate Glass Ion Sources for Electrospray Thruster

Aerospace ◽  
2021 ◽  
Vol 8 (10) ◽  
pp. 297
Author(s):  
Yuntian Yang ◽  
Dawei Guo ◽  
Xiaokang Li ◽  
Leimin Deng ◽  
Bixuan Che ◽  
...  
Keyword(s):  
Porous Media ◽  
Performance Improvement ◽  
Porous Glass ◽  
Borosilicate Glass ◽  
Positive Impact ◽  
Processing Technique ◽  
The Novel ◽  
Machine Method ◽  
And Performance

The porous-media-based electrospray thruster is a cutting-edge micropropulsion technology that can revolutionize the capabilities of microsatellites. This paper reports the design, fabrication, and characterization of a novel porous-media borosilicate glass electrospray thruster. The porous glass used here is integrally formed by the phase separation method, which make it display outstanding pore uniformity and processability. The picosecond ultraviolet laser processing technique is applied to machine 361 emitters out of glass. Performance characteristic experiments are conducted with the thruster passively fed with ionic EMI-BF4 liquid. The results reveal that the per-emitter can emit up to 200.46 nA of ion current at 2 kV. The novel porous glass and the corresponding machine method present an opportunity to attain more-controllable emitter shapes, which has a positive impact on thruster lifetime and performance improvement.

scholarly journals Multidisciplinary challenge in the design of a MWCNTs-based polymer smart structure

2018 ◽  
Vol 233 ◽  
pp. 00024 ◽  
Author(s):  
Maurizio Arena ◽  
Massimo Viscardi ◽  
Liberata Guadagno ◽  
Luigi Vertuccio ◽  
Giuseppina Barra
Keyword(s):  
Smart Structures ◽  
Smart Structure ◽  
Self Healing ◽  
The Novel ◽  
Bulk Materials ◽  
Consumer Safety ◽  
Multi Walled Carbon Nanotubes ◽  
And Performance ◽  
Walled Carbon Nanotubes

Smart structures represent of course a current challenge for the application on the aircrafts. Dealing for example with morphing and variable-shape structures, the skin needs to face extremely high strains, while withstanding the operational loads in order to ensure a smooth profile to the complete system. In this context, the authors led the design and manufacturing of carbon fiber-reinforced composite panels, including different filler infusions based on multi-walled carbon nanotubes (MWCNTs) technology. The vibro-acoustic tests have been carried out on an innovative formulation for the characterization of the damping properties related to such micro-handling treatments. The percentage of nano-filler has been chosen so as to be close to the percolation threshold of the material (about 5wt%). As a result of synergic collaboration between Smart Structures Lab of University of Naples “Federico II” and University of Salerno within H2020-MASTRO (Intelligent bulk MAterials for Smart TRanspOrt industries) research project, a multi-functional composite concept has been idealized and developed. The main purpose is to develop intelligent bulk materials for the transport field based on the novel concepts like self-sensing, self-deicing, self-curing, self-healing and selfprotection methodologies to enhance consumer safety, component life-span and performance while reducing maintenance and manufacturing costs. The functionality of the developed components will be demonstrated under relevant conditions at prototype level with special attention to the aerospace structures.

Rancang Bangun Alat Olahan Minyak Kelapa

2016 ◽  
Vol 10 (1) ◽  
pp. 70-77
Author(s):  
Jantri Sirait ◽  
Sulharman Sulharman
Keyword(s):  
Electric Motor ◽  
Performance Test ◽  
Production Capacity ◽  
Coconut Oil ◽  
Heating Time ◽  
Design Tool ◽  
Coconut Milk ◽  
Heating Process ◽  
And Performance ◽  
Time Required

Has done design tool is a tool of refined coconut oil coconut grater, squeezer coconut milk and coconut oil heating, with the aim to streamline the time of making coconut oil and coconut oil increase production capacity. The research method consists of several stages, among others; image creation tool, procurement of materials research, cutting the material - the material framework of tools and performance test tools. The parameters observed during the performance test tools is time grated coconut, coconut milk bleeder capacity, the capacity of the boiler and the heating time of coconut oil. The design tool consists of three parts, namely a tool shaved coconut, coconut milk wringer and coconut milk heating devices. Materials used for the framework of such tools include iron UNP 6 meters long, 7.5 cm wide, 4 mm thick, while the motor uses an electric motor 0.25 HP 1430 rpm and to dampen the rotation electric motor rotation used gearbox with a ratio of round 1 : 60. the results of the design ie the time required for coconut menyerut average of 297 seconds, coconut milk wringer capacity of 5 kg of processes and using gauze pads to filter coconut pulp, as well as the heating process takes ± 2 hours with a capacity of 80 kg , The benefits of coconut oil refined tools are stripping time or split brief coconut average - average 7 seconds and coconut shell can be used as craft materials, processes extortion coconut milk quickly so the production capacity increased and the stirring process coconut oil mechanically.ABSTRAKTelah dilakukan rancang bangun alat olahan minyak kelapa yaitu alat pemarut kelapa, pemeras santan kelapa dan pemanas minyak kelapa, dengan tujuan untuk mengefisiensikan waktu pembuatan minyak kelapa serta meningkatkan kapasitas produksi minyak kelapa. Metode penelitian terdiri dari beberapa tahapan antara lain; pembuatan gambar alat, pengadaan bahan-bahan penelitian, pemotongan bahan - bahan rangka alat dan uji unjuk kerja alat. Parameter yang diamati pada saat uji unjuk kerja alat adalah waktu parut kelapa, kapasitas pemeras santan kelapa, kapasitas tungku pemanas serta waktu pemanasan minyak kelapa. Rancangan alat terdiri dari tiga bagian yaitu alat penyerut kelapa, alat pemeras santan kelapa dan alat pemanas santan kelapa. Bahan yang dipergunakan untuk rangka alat tersebut  yaitu besi UNP panjang 6 meter, lebar 7,5 cm, tebal 4 mm, sedangkan untuk motor penggerak menggunakan motor listrik 0,25 HP 1430 rpm dan untuk meredam putaran putaran motor listrik dipergunakan gearbox  dengan perbandingan putaran 1 : 60. Hasil dari rancangan tersebut yaitu waktu yang dibutuhkan untuk menyerut kelapa rata-rata 297 detik, kapasitas alat pemeras santan kelapa 5 kg sekali proses dan menggunakan kain kassa untuk menyaring ampas kelapa, serta Proses pemanasan membutuhkan waktu ± 2 jam dengan kapasitas 80 kg. Adapun keunggulan alat olahan minyak kelapa ini adalah waktu pengupasan atau belah kelapa singkat rata – rata 7 detik dan tempurung kelapa dapat digunakan sebagai bahan kerajinan, proses pemerasan santan kelapa cepat sehingga kapasitas produksi meningkat dan proses pengadukan minyak kelapa secara mekanis. Kata kunci : penyerut, pemeras, pemanas,minyak kelapa,olahan minyak kelapa.

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