Papers by Keyword: Anneal

Abstract: To relax the surface residual stress of fused silica lens or windows irradiated by CO₂ laser, it was proposed to treat it at high temperature above glass strain temperature in the traditional annealing process. However it is a time and energy consuming process, and a distortion will be introduced during the heat treatment. To deal with these problems, annealing temperatures lower than glass strain temperature were applied to the annealing process and a new scheme was designed in this paper. An numerical model was built to simulate the laser induced residual stress and optimize the stress variation in the annealing process. The surface stress of fused silica can be relaxed and deformation induced by heat treating can be ignored.

Abstract: Casting Mg-Li alloy samples were subjected to annealing and aging treatment respectively, and the corrosion resistance of different samples was investigated by immersion test and electrochemical impedance spectroscopy measurement in 3.5% NaCl solution. The results show that the corrosion resistance of the as-cast sample is the best,the aged sample is the second, and the annealed sample is the worst to resist corrosion.

Abstract: The work introduces the spectra of fluorescent derivatives which have been annealed. It’s usually unstable when heated or electrified, showing the red-shift and emerging new emission peak. We analyze the connection between emission peak and temperature. OF3R4, OF3R6, OF4R4, which are characterized by NMR. By contract, different temperatures and materials have similar phenomenon.

Abstract: Carbon decomposition of liquor afger desilication from nephine was investigated, aluminium oxide was prepard by anneal of Al (OH)₃ separated out from carbon decompositon, and analysis of radionuclide of both above process was performed. The results show decomposition rate of sodium aluminate can be obtained when experiments of carbon decomposition of liquor after desilication using CO₂ of hight concentration, and it is beneifit for the crystal growth of Al (OH)₃, filtration and separation. Great mass of nuclide exists in the mother solution of carbon decomposition, and few into Al (OH)₃, which could be regarded as wiout radioactive contamination. .

Abstract: MnO₂ nanoparticle was produced using liquid coprecipitation method, and nanorod and nanowire were produced using hydrothermal method and annealing. SEM and EDS were used to examine the morphology and the elements of the samples. The diameter of particle is about 300nm, the diameter of rod is about 200-300nm, the diameter of wire is about 50-70nm. The electrochemical characteristics were tested using galvanostatic charge-discharge cycling. The results demonstrat that the prepared MnO₂ have a good pseudocapacitance behavior and power characteristic. And the specific capacitor (SC) is up to 260.09F/g.

Abstract: GaN thin films have been deposited on Si (111) substrates by pulsed laser deposition (PLD) of a GaN target in nitrogen atmosphere. An Nd: YAG pulsed laser with a wavelength of 1064 nm was used as a laser source. The results indicate that the GaN thin films deposited only by PLD are amorphous. By annealing in an NH3 atmosphere, the quality of the GaN thin films is improved, and the crystallzinity GaN thin films were obtained. The influence of annealing temperature on the crystallinity, structure, surface morphology and optical properties of GaN films have been examined by X-ray diffraction (XRD), atomic force microscopy (AFM) and infrared spectrum. In our experimental conditions, the GaN thin films deposited by PLD with a laser energy of 250 mJ, growth temperature of 800 °C and annealed at 1000 °C have the best surface morphology and crystalline quality.

Abstract: Seeking for reducing the cost of hydrogen energy fuel cells, one of the key points is reduce Pt loading in Pt/C catalytic electrode. Meanwhile, there is no negative impact about efficiency of electrode reactions. We manufactured PtCuCeO_x catalyst for fuel cell by Ion Beam Sputtering (IBS). In this paper, the electrodes were processed by different annealing temperature and acid treatment temperature for post-processing. An appropriate amount of Cu dopant can reduce the Pt loading, and the catalytic performance won't reduce. Doping CeO_x refined PtCu alloy crystal particle, active surface area of the electrode was improved. It had shown that Pt atoms accounted for 72%, Pt load 0.0618mg/cm2 by SEM + EDS and ICP-AES data. Performance of electrochemistry was increased by 40.5%. It showed the characteristics had low Pt loading with high performance of hydrogen evolution.

Abstract: NiZnO films were grown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD). Then the films were annealed in vacuum at different temperatures for 1h. The UV emission peak was blue shifted in the photoluminescence (PL) spectra and a dramatic shift of (002) diffraction peak to higher angle was observed in X-ray diffraction (XRD) pattern with the increasing anneal temperature. It showed the band gap and the lattice parameter of NiZnO had been affected by anneal in vacuum. From the X-ray photoelectron spectroscopy (XPS) of the NiZnO film, we can find that the anneal temperature had an important effect on the content of each element in NiZnO quantificationally. In addition, the value of x in NiZnO varied slightly with the anneal temperature increasing. The above phenomena indicated that anneal in vacuum could slightly adjust the percentage of Ni indirectly in NiZnO film and offer a good idea in NiZnO devices facture.

Abstract: This article aims to show the effects of the EDM process that influences the surface hardness by comparing the hardness values before and after the spark on the plastic mould steel AISI P20. Divided by the heat treatment, there were three different hardness levels: 1) the plastic mould steel AISI P20 through the process of quenching with the hardness value in the range of 690-710 HV; 2) the steel through the process of quenching and then annealing with the hardness value in the range of 470-490 HV; and 3) the non-heat treatment steel (raw material) with the hardness value in the range of 300-320 HV. The condition of EDM spark on the surface workpiece was 3 mm of depth and 10 mm of diameter copper electrode. The experiment was carried out under the cover of hydrocarbon, using dielectric cooling, and removing debris by the side flushing through the 6 mm of diameter pipe with the flow rate of 15 liters per minute. The experiment parameters included on-time duty factor variable, off-time duty factor variable, and current. Based on the experiment, it was found that when the duty factor increased, the hardened workpiece showed the less surface hardness value. At the same time, the annealed, and the non-heat treatment workpieces showed that the hardness values were proportional to the duty factor and the current of the EDM process.

Abstract: The theoretical and experimental work is executed for study the impact of anneal on the grain size, electromigration (EM) reliability of copper (Cu) interconnect system, and subsequently find the optimized anneal condition. EM accelerated failure tests are carried on the Cu interconnect samples with 0.2μm line width, which are produced at different anneal conditions. It is shown that anneal can lead the grains to grow to become larger, and lessen the EM diffuse path. As a result, the EM diffuse active energy (Ea) of Cu interconnect is enhanced, and the ability against the EM of Cu interconnect is improved. By comparing the EM character of Cu interconnects produced at different anneal conditions, results can be obtained as below: the anneal time should be maintained 40 minutes at least in order to achieve fully anneal and excellent ability against the EM; the anneal temperature should be set about 350°C approximately, because high temperature (beyond 400°C) anneal can induce the other reliability issues, which will have a strong negative impact on the EM reliability. The results in this paper are significance for Cu interconnect technology optimize and are beneficial to improve the EM reliability of the Cu interconnect system.