scholarly journals KETANGGUHAN RETAK, KEKERASAN DAN KONDUKTIVITAS IONIK CSZ SEBAGAI ELEKROLIT PADAT SOFC DENGAN PENAMBAHAN CuO

2015 ◽  
Vol 16 (2) ◽  
pp. 85
Author(s):  
Ila Lailatun Sholihah ◽  
Dani Gustaman Syarif ◽  
Andhy Setiawan

ABSTRAK KETANGGUHAN RETAK, KEKERASAN DAN KONDUKTIVITAS IONIK CSZ SEBAGAI ELEKROLIT PADAT SOFC DENGAN PENAMBAHAN CuO. Penelitian mengenai pengaruh penambahan CuO terhadap konduktivitas ionik, kekerasan dan ketangguhan retak CSZ sebagai elektrolit padat SOFC telah dilakukan. CSZ didoping dengan CuO dengan konsentrasi 0, 1, dan 2 % berat. Pelet CSZ yang didoping CuO dikompaksi dengan tekanan 4 ton/cm2 dan disinter pada suhu 1475 0C selama 3 jam. Konduktivitas ionik diukur dengan menggunakan alat LCR meter. Konduktivitas ionik CSZ dengan doping 0, 1, dan 2 % berat CuO adalah 0,063 mS/cm; 0,110 mS/cm; dan 0,082 mS/cm. Kekerasan dan ketangguhan retak diukur dengan metode vickers menggunakan alat uji keras Zwick. Hasil kekerasan vickers berturut-turut 9,9 GPa; 12,1 GPa; dan 10,5 GPa, dan ketangguhan retak berturut-turut 1,61 MPa/m0,5; 1,85 MPa/m0,5; dan 1,54 MPa/m0,5. Analisis struktur kristal dilakukan dengan menggunakan XRD. Hasil analisis menunjukkan bahwa keramik yang dibuat berfase kubik FCC. Analisis struktur mikro dengan menggunakan mikroskop optik menunjukkan bertambahnya ukuran butir dengan peningkatan 1% berat CuO. Secara keseluruhan penambahan CuO dengan konsentrasi 1% berat dapat memperbaiki sifat listrik dan sifat mekanik CSZ sebagai elektrolit padat. ABSTRACT FRACTURE TOUGHNESS, HARDNESS AND IONIC CONDUCTIVITY OF CSZ AS SOLID ELECTROLYTE WITH ADDITION OF CuO. A research on effect of CuO addition on ionic conductivity, hardness and fracture toughness of CSZ as solid electrolyte had been conducted. CSZ was doped with 0, 1, and 2 wt % CuO. Pellets of CuO doped CSZ had been prepared by pressing with pressure of 4 ton/cm2 and sintered at 1475oC for 3 hours. Ionic conductivity was measured by means of LCR meter. Ionic conductivity values of CSZ with doped 0, 1, and 2 % CuO were 0.063 mS/cm, 0.110 mS/cm, and 0.082 mS/cm. Hardness and fracture toughness were measured by vickers method using a hardness tester Zwick. The measured vickerss hardness were 9.9 GPa, 12.1 GPa and 10.5 GPa, and fracture toughness were 1.61 MPa/m0,5, 1.85 MPa/m0,5, and 1.54 MPa/m0,5. Crystal structure analysis was done by using XRD. The analysis result showed that the prepared ceramics have cubic phase of FCC. Microstructure analysis by using an optical microscope showed that grain size increased with the increased of 1 wt % CuO. The addition of CuO at conscentration of 1 wt % can improve the electrical and mechanical properties of CSZ as solid electrolyte.

2012 ◽  
Vol 31 (6) ◽  
pp. 701-706 ◽  
Author(s):  
Süleyman Tekeli ◽  
Bülent Aktaş ◽  
Mustafa Küçüktüvek

AbstractIn this study, the effect of erbium oxide (Er2O3) addition on the microstructure, sinterability and mechanical properties of cubic zirconia (c-ZrO2) was investigated. 0–15 wt% Er2O3 and c-ZrO2 powders were mixed by means of colloidal processing and the specimens were sintered at different temperatures for 1 hour. The XRD results showed the existence of cubic crystal structure in all specimens. The lattice parameter of the specimens decreased with increasing Er2O3 addition up to 10 wt% and remained unchanged after this amount. The grain size of the Er2O3 doped c-ZrO2 specimens dropped up to 5 wt% Er2O3 addition and stayed almost unchanged at higher Er2O3 contents. Both hardness and fracture toughness measurements were done using Vickers hardness tester. The fracture toughness values of the undoped, 1, 5, 10 and 15 wt% Er2O3 doped c-ZrO2specimens were found to be 1.64 MPam1/2, 1.77 MPam1/2, 2.06 MPam1/2, 2.57 MPam1/2 and 2.31 MPam1/2 respectively.


2014 ◽  
Vol 915-916 ◽  
pp. 992-995
Author(s):  
Shuang Liu ◽  
Wei Tan Cui ◽  
Hong Wu Zhang ◽  
Yong Quan Ma

The fracture reasons of 500kV high-voltage disconnectors hoops were analyzed. The fracture appearance, composition of chemical elements, metallographic, mechanical properties of the fractured hoops were investigated by ICP-AES, SEM, optical microscope, brinell hardness tester, universal testing machine. The test results that one reason is substandard products of this batch hoop. The composition of chemical elements and mechanical properties is fails to comply with applicable standards prescribed and the casting defects are found. Another reason is that the large pre-tightening force and tightens reverse order.


2012 ◽  
Vol 580 ◽  
pp. 505-508 ◽  
Author(s):  
Yu Shan Li

As-cast AZ61 magnesium alloy was treated by solution under a high-pressure of 3 Gpa at different temperatures, atmospheric temperature, 200, 400, 600, 800 and 1000 °C. The microstructure of the products was observed by optical microscope. The mechanical properties of the products were investigated by brinell hardness tester and tensile testing. The results show that increasing solution temperature promotes the dissolution into α-Mg matrix of β-Mg17Al12 phase of AZ61 alloy, especially for over 400 °C. With increasing solution temperature, the tensile strength and elongation percentage of AZ61 increase gradually, but the hardness decreases.


2012 ◽  
Vol 500 ◽  
pp. 623-628 ◽  
Author(s):  
Yu Huan Fei ◽  
Chuan Zhen Huang ◽  
Han Lian Liu ◽  
Bin Zou

Al2O3-TiN-TiC ceramic materials with different MgO content were fabricated by hot-pressing technique. The MgO volume percent was varied from 0vol% to 5vol%. The mechanical properties such as flexural strength, Vickers hardness and fracture toughness were tested. The phase composition of the sintered body was analyzed by XRD while the microstures of the sintering body were observed by OM (Optical Microscope) and SEM. The effects of MgO content on the mechanical properties and microstructures of Al2O3-TiN-TiC were investigated. The results shows that the addition of MgO can change the phase composition of the sintered ceramic materials which displayed with diverse solid solutions and intermetallic compounds. Meanwhile the new sintering products changed the the microstructure morphology which made the crack path complex and affected the mechanical properties.


Materials ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 819 ◽  
Author(s):  
Andrea Dorigato ◽  
Daniele Rigotti ◽  
Alessandro Pegoretti

The aim of this work was the development of a thermoplastic/thermosetting combined system with a novel production technique. A poly(caprolactone) (PCL) structure has been designed and produced by fused filament fabrication, and impregnated with an epoxy matrix. The mechanical properties, fracture toughness, and thermal healing capacities of this blend (EP-PCL(3D)) were compared with those of a conventional melt mixed poly(caprolactone)/epoxy blend (EP-PCL). The fine dispersion of the PCL domains within the epoxy in the EP-PCL samples was responsible of a noticeable toughening effect, while in the EP-PCL(3D) structure the two phases showed an independent behavior, and fracture propagation in the epoxy was followed by the progressive yielding of the PCL domains. This peculiar behavior of EP-PCL(3D) system allowed the PCL phase to express its full potential as energy absorber under impact conditions. Optical microscope images on the fracture surfaces of the EP-PCL(3D) samples revealed that during fracture toughness tests the crack mainly propagated within the epoxy phase, while PCL contributed to energy absorption through plastic deformation. Due to the selected PCL concentration in the blends (35 vol %) and to the discrepancy between the mechanical properties of the constituents, the healing efficiency values of the two systems were rather limited.


2008 ◽  
Vol 55-57 ◽  
pp. 245-248 ◽  
Author(s):  
Nattiree Chiranavanit ◽  
Anak Khantachawana ◽  
N. Anuwongnukroh ◽  
Surachai Dechkunakorn

Ni-Ti alloy wires have been widely used in clinical orthodontics because of their properties of superelasticity (SE) and shape memory effect (SME). The purpose of this study was to assess the mechanical properties and phase transformation of 50.7Ni-49.3 Ti (at%) alloy (NT) and 45.2Ni-49.8Ti-5.0Cu (at%) alloy (NTC), cold-rolled with various percent reductions. To investigate SE and SME, heat-treatment was performed at 400°C and 600°C for 1 h. The specimens were examined using an Energy-Dispersive X-ray Spectroscope (EDS), Differential Scanning Calorimeter (DSC), Universal Testing Machine (Instron), Vickers Hardness Tester and Optical Microscope (OM). On the three-point bending test, the superelastic load-deflection curve was seen in NTC heat-treated at 400°C. Furthermore, NT heat-treated at 400°C with 30% reduction produced a partial superelastic curve. For SME, no conditions revealed superelasticity at the oral temperature. Micro-hardness value increased with greater percentage reduction. The average grain size for all specimens was typically 55-80 µm. The results showed that locally-made Ni-Ti alloys have various transformation behaviors and mechanical properties depending on three principal factors: chemical composition, work-hardening (the percent reduction) and heat-treatment temperature.


2006 ◽  
Vol 306-308 ◽  
pp. 845-850 ◽  
Author(s):  
Joong-Suk Kook ◽  
Tadaharu Adachi

In this study, a manufacturing process for glass fiber reinforced plastics (GFRP) laminates was developed to improve volume fraction of fibers and mechanical properties. The manufacturing process is combination with wet lay-up and vacuum curing under atmosphere pressure for production of large and complicated structure as a leisure boat and so on. Several kinds of GFRP laminates were produced to consider optimum conditions of the process from viewpoint of volume fraction of fibers and mechanical properties. Volume fractions of fibers in GFRP laminates were measured and cross sections were observed by an optical microscope. The volume fraction in the GFRP laminate made by the suggested method was improved to 41 %, although the one made by conventional wet lay-up method was 17.7 %. Because a lot of large voids included in the laminates were drastically decreased due to the methods. For each laminate, three-point bending test was performed to measure elastic modulus and fracture toughness. Elastic modulus was improved from 5.39 GPa to 8.91 GPa with high volume fractions of fibers. Fracture toughness was improved from 8.19 MPa m1/2 to 16.6 MPa m1/2. Therefore, it was obtained that the method combined with wet lay-up and vacuum curing is easy process for manufacturing large and complicated structure to improve excellent mechanical properties and accuracy of structural shape.


2016 ◽  
Vol 879 ◽  
pp. 932-937
Author(s):  
Jun Hyong Kim ◽  
Auezhan Amanov ◽  
Myeong Sung Kang ◽  
Hak Doo Kim ◽  
Young Sik Pyun ◽  
...  

This present work was carried out to characterize the microstructure and mechanical properties of austenitic stainless steel (SS) 316L to dissimilar welding of Inconel 52 and Inconel 82 fillers that were treated by ultrasonic nanocrystalline surface modification (UNSM) technique. The microstructure and hardness map of the specimens were characterized by optical microscope (OM) and micro-hardness tester. The increase in hardness and refinement in grain size after UNSM treatment were found for the SS 316L/52 and SS 316L/82. In addition, the induced compressive residual stress in the surface layer of base SS 316L was measured. It is expected that the increased hardness into several microns in depth and modified microstructure with a severe plastically deformed surface layer by UNSM technique can increase the resistance to corrosion and extend the service life of pressurized water reactors (PWRs).


2020 ◽  
Vol 58 (7) ◽  
pp. 453-458
Author(s):  
Seong-Eun Kim ◽  
Su-Hwan Hong ◽  
In-Jin Shon

Tungsten carbides are quite attractive for their superior properties, e.g., high melting point, high hardness, high thermal and electrical conductivities, and relatively high chemical stability. Tungsten carbides with a binder metal, for example Co or Ni, are mainly used to produce cutting tools, nozzles and molds in the composite form. But these binder materials show inferior chemical characteristics compared to the tungsten carbide phase. There has been enormous interest recently in finding alternative binder phases because of the low corrosion resistance and the high cost of Ni or Co. Al has been reported as an alternative binder for WC and TiC, since Al is less expensive and shows a higher oxidation resistance than Ni or Co. Nanostructured WC-BN-Al composites were rapidly sintered using high-frequency induction heated sintering (HFIHS). The microstructure and mechanical properties (fracture toughness and hardness) were investigated by Vickers hardness tester and FE-SEM. The HFIHS method induced very fast densification, nearly at the level of theoretical density, and successfully prohibited grain growth, resulting in nano-sized grains. The fracture toughness was improved by consolidation facilitated by adding Al to the WC-BN matrix. The 5vol % Al added WC-BN composites showed higher mechanical properties (hardness and fracture toughness than the WC-BN composite.


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