Influence of compression on thermal and corrosion behavior of Fe_(78)Si_9B_(13) glassy alloy

The Fe78Si9B13 glassy ribbons were compressed at room temperature with different pressures. The thermal and corrosion behaviors were investigated using various experimental techniques. The X-ray diffraction （XRD） and dilatometer （DIL） results show that the Fe78Si9B13 ribbons are in full amorphous state after pressing and the amount of free volume increases monotonically with increasing pressure. The corrosion resistance of the glassy alloys in various solutions decreases after compression at 10 MPa, but increases after compression at 20 MPa. The non-monotonic change of corrosion resistance is consistent with the result of electrical resistivity, which can be explained by the combining action of free volume that is introduced by the compression and the segregation of Si atoms in the samples.

Fabrication and thermal performance of grooved-sintered wick heat pipe

Some novel grooved-sintered composite wick heat pipes(GSHP) were developed for the electronic device cooling.The grooved-sintered wicks of GSHP were fabricated by the processes of oil-filled high-speed spin forming and solid state sintering.The wick could be divided into two parts for liquid capillary pumping flow:groove sintered zone and uniform sintered zone.Both of the thermal resistance network model and the maximum heat transfer capability model of GSHP were built.Compared with the theoretical values,the heat transfer limit and thermal resistance of GSHP were measured from three aspects:copper powder size,wick thickness and number of micro grooves.The results show that the wick thickness has the greatest effect on the thermal resistance of GSHP while the copper powder size has the most important influence on the heat transfer limit.Given certain copper powder size and wick thickness,the thermal resistance of GSHP can be the lowest when micro-groove number is about 55.

Performance of Water and Mercury Triple Points Reference Cells under Adiabatic Conditions

Two new miniature metallic sealed-cells containing the triple point of water, WTP （273.16 K） and the triple point of mercury, HgTP （234.3156 K） have been constructed for the realization of the International Temperature Scale of 1990 （ITS-90） at the National Institute of Standards （NIS-Egypt）. The two new cells, in addition to a previously realized argon and oxygen triple point cells, will provide facilities for the calibration of capsule-type standard platinum resistance thermometers （CSPRTs） at one single run. Many phase transition plateaux were carried out and compared to the laboratory large reference cells using the same thermometers in order to test the performance of the new cell.

Tailored Sr-Co-free perovskite oxide as an air electrode for high-performance reversible solid oxide cells

Sr-Co containing perovskite oxides are prospective air electrode candidates for reversible solid oxide cells(RSOCs).However,their efficiencies are limited by Sr segregation and the high thermal expansion coefficient(TEC)of Cobased perovskites.Herein,La_(0.6)Ca_(0.4)Fe_(0.8)Ni_(0.2)O_(3-δ)(LCa FN)is tailored as an Sr-Co-free perovskite air electrode for highperformance RSOCs.Compared with La_(0.6)Sr_(0.4)Fe_(0.8)Ni_(0.2)O_(3-δ)(LSFN)and La_(0.6)Sr_(0.4)Co_(0.2)Fe_(0.8)O_(3-δ)(LSCo F),LCa FN has a high electrical conductivity (297 S cm^(-1)),TEC compatibility(11.2×10^(-6)K^(-1)) and improved chemical stability.Moreover,LCa FN has high oxygen reduction reaction(ORR)activity with a low polarization resistance(0.06Ωcm^(2)) at 800℃.A single-cell NiYSZ/YSZ/gadolinium-doped ceria(GDC)/LCa FN-GDC operated at 800℃ yields a maximum power density of 1.08 W cm^(-2) using H_(2) as fuel.In the solid oxide electrolysis cell(SOEC)mode,the cell can achieve a current density of approximately 1.2 A cm^(-2) at 1.3 V with 70% humidity at 800℃.The cell exhibits good reversibility and remains stable in continuous SOEC and solid oxide fuel cell(SOFC)modes.These findings indicate the potential application of LCa FN as an air electrode material for RSOCs.