Effects of Annealing Process on Crystallization and Low Temperature Resistance Properties of PP-R Composites

The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wide-angle X-ray diffraction（WAXD）, and dynamic mechanical analysis（DMA）, and scanning electron microscopy（SEM）. The experimental results indicated that the annealing process significantly influenced the comprehensive properties of PP-R composites. At temperatures below 23 ℃, the impact strength of the PP-R composites annealed at 120 ℃ for 6 h was relatively high at 74.73 k J/m^2, which was 16.8% higher than that of the samples annealed at 80 ℃ for 6 h. At low temperatures（-30-0 ℃）, the impact strength ranged from approximately 13.31 k J/m^2 to 54.4 k J/m^2. In addition, the annealing process conducted at 120 ℃ for 6 h improved the crystalline structure and low-temperature toughness of the PP-R composites and induced α-form to β-form crystal transformation. The work provides a possible method to reinforce and toughen the semicrystalline polymer at low temperatures（-30-0 ℃） by annealing.

Microstructures and Optical Properties of Sol-gel Derived Ba_(0.9)Sr_(0.1)TiO_3 Thin Films Formed by Different Annealing Process

We investigated the effect of annealing process on microstructures and optical properties of the sol-gel derived Ba0.9Sr0.1TiO3 （BST） films. The BST films, fabricated by layer-by-layer high-temperature （≥ 650 ℃） annealing process, had laminated structures consisting of alternating dense and porous BST layers, and exhibited excellent optical performance as Bragg reflectors. The Bragg reflection characteristic can be enhanced with increasing annealing temperature. Those BST films fabricated at temperatures lower than 650 ℃ displayed uniform cross-sectional morphologies even treated at a higher temperature. The difference in the microstructures of the BST thin films was also discussed.

Influence of Pressure on the Annealing Process of β-Ca_2SiO_4(C_2S) in Portland Cement

Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-speciality grout. Dicalcium silicate （Ca2SiO4） is the primary constituent of a number of different types of cement. The β-Ca2SiO4 phase is metastable at room temperature and will transform into β-Ca2SiO4 at 663K. In this work, Portland cement is annealed at a temperature of 950K under pressures in the range of 0-5.5 CPa. The high pressure experiments are carried out in an apparatus with six anvil tops. The effect of high pressure on the obtaining nano-size β-Ca2SiO4 （C2S） process is investigated by x-ray diffraction and transmission electron microscopy. Experimental results show that the grain size of the C2S decreases with the increase of pressure. The volume fraction of the C2S phase increases with the pressure as the pressure is below 3 CPa, and then decreases （P 〉 3 GPa）. The nano-effect is very important to the stabilization of β-Ca2SiO4. The mechanism for the effects of the high pressure on the annealing process of the Portland cement is also discussed.

Effect of annealing process on structures and ferroelectric properties of Ca_(0.4)Sr_(0.6)Bi_(3.95)Nd_(0.05)Ti_4O_(15) thin films

Ca0.4Sr0.6Bi3.95Nd0.05Ti4O15 （C0.4S0.6BNT） ferroelectric thin films were prepared on Pt/Ti/SiO2/Si substrates by sol-gel method. Effect of annealing process （time and temperature） on structures and ferroelectric properties of C0.4S0.6BNT thin film was investigated. The relative intensity of （200） peak increased first then decreased with annealing temperature and became predominant at 800 ℃. In contrast, no evident change could be observed in the （001） peak. The remnant polarization （Pr） and coercive field （Ec） for C0.4S0.6BNT film annealed at 800℃ for 5 min were 21.6μC/cm2 and 68.3 kV/cm, respectively.

Effect of hot-band annealing process on microstructure,texture,and r-value of final sheets of ferritic stainless steel

In this paper,the effect of different annealing processes on the microstructure,texture,and formability of ferritic stainless steel was studied in detail.The results showed that the grain size in the final sheet was larger and the recrystallization texture was more uniform after the final recrystallization annealing of hot-rolled steel with continuous annealing than that without annealing or with batch annealing.In addition,the final sheet had a higher average r-value and the lowest planar anisotropy.

Surface Carbonization of GaN and the Related Structure Evolution during the Annealing Process

To explain the stabilization mechanism of the carbon-ion-implanted GaN under the diamond growth environment,the luminescence characteristics and structure evolution correlative with sites＇ carbon atoms located for highfluence carbon-ion-implanted Ga N are discussed. GaN is implanted with carbon ion using fluence of 2×10^（17） cm^（-2） and energy of 45 keV. Then the implanted samples are annealed at 800℃ for 20 min and 1 h under the N_2 atmosphere. The luminescence characteristics of carbon-ion-implanted GaN are evaluated by photoluminescence spectrum at wavelength 325 nm. The lattice damage of Ga N is characterized by Raman spectrum and the corresponding vacancy-defect evolution before and after annealing is measured by slow positron annihilation. The results show that most of the carbon atoms will be located at the interstitial sites after carbon ion implantation due to the weak mobility. As the implanted samples are annealed, strong yellow luminescence is emitted and the vacancies for Ga（V_（Ga）） are reduced resulting from the migration of interstitial carbon（C_i） and formation of complexes（CGaand/or C_（Ga）-C_i） between them. As the annealing time is prolonged, the carbon ions accommodated by the vacancies are saturated, vacancy clusters with carbon atoms appear and the concentration of C_（Ga） diminishes, which will have an adverse effect on the diamond film nucleation and growth.

Corrosion behavior of dual-main-phased(Nd_(0.8)Ce_(0.2))2Fe_(14)B magnets with and without annealing process

In this work,the corrosion behavior of the sintered Nd_(2)Fe_(14)B in which Nd was substituted by Ce to form dual-main-phased magnet with/without annealing process was studied.The mass loss of as-sintered magnets(SM)is larger than that of as-annealed magnets(AM)in the accelerated corrosion tests.In particular,the mass loss of SM increases sharply when the corrosion time increases to48 h.The free corrosion current of the SM samples is larger than that of AM in 0.1 mo1·L^(-1)HCl;this is due to that the content of RE-rich phase at the intergranular triple junctions(TJs)of the SM samples is larger than that of AM samples and the corrosion rate of the RE-rich phase at the TJs is higher than that at grain boundaries.But the free corrosion current of the SM samples is smaller than that of AM samples in 3.5 wt%NaCl as the electron transfer resistance(R_(ct))of SM is larger than that of AM.Inductive loop in the Nyquist diagrams at low frequency of SM is observed,which originated from the pitting.It shows that pitting of SM occurs more easily than that of AM.Corrosion morphology of samples indicates that the corrosion area of SM is bigger and deeper than that of AM after accelerated corrosion for 60 h.Through the annealing process,the distribution of rare-earth-rich phase becomes more uniform,which changes the free corrosion current and effectively suppresses the occurrence and propagation of pitting.

The Effect of Annealing Processes on Fish-Scaling Resistance in V-Ti-N Microalloyed Low Carbon Steel Sheets for Enameling

Annealing process will have greatly influence on microstructure of V,Ti and N microalloyed low carbon steel sheets.In this paper,the experimental steels with given amount of V,Ti and N elements were annealed at 4 routes to simulate batch annealing and continuous annealing processes,respectively.The enameling tests for the annealed steel sheets were undergone in same enameling and firing processes to study the relationship between microstructure and fishscale.The result shows that the cold-rolled steel sheets annealed at 750 ℃for 6 minutes even for 30 minutes exhibit excellent fishscale resistance.

Semisolid-rolling and annealing process of woven carbon fibers reinforced Al-matrix composites

Semisolid-rolling method was successfully developed to prepare the Ni-coated woven carbon fibers reinforced Al-matrix composite. Due to the appropriate matrix flowability and rolling pressure, the Al-matrix could infiltrate into the woven fibers sufficiently and attach to the reinforcements closely forming a smooth interface. The rolling speed of 4 rad/min offered a subtle equilibrium between the heat transfer and the material deformation. The covering matrix should be controlled at semisolid state to provide a better infiltration behavior and a protective effect on the carbon fibers. With the addition of fibers, an improvement for more than 25% was obtained in the bending strength of the materials. Furthermore, the woven carbon fibers could strengthen the composite in multiple directions, rather than only along the fiber longitudinal directions. The annealing process promoted the Ni coating to react with and to diffuse into the matrix, resulted in an obvious increase of the bending strength.

Investigation the improvement of high voltage spinel LiNi_(0.5)Mn_(1.5)O_(4) cathode material by anneal process for lithium ion batteries

The spinel LiNi_(0.5)Mn_(1.5)O_(4)(LNMO)has been attracted great attention as lithium ion cathode material due to its high voltage and large energy density.However,the practical application of LNMO is still limited by poor cycling stability.Herein,to improve the cycling stability of spinel LNMO,it was treated with anneal process at 900℃for 2 h after prepared by traditional solid-state method(LNMO-A).LNMO-A sample presented better electrochemical property especially under high rate,with capacity of 91.2 mAhg^(-1) after 1000 cycles under 10 C.Its superior electrochemical property was ascribed to the anneal process,resulting a stable crystal structure,indicated by XRD and Raman results of electrodes after 1000 cycles under 10 C and the longer solid-solution reaction,revealed by in-situ XRD.In addition,the optimized particle size,micro morphology and the larger BET area surface induced by the recrystallization in anneal process also contributes to its superior electrochemical property.What's more,the thin layer,which interacted LNMO-A particles with each other,induced by particles remelting in anneal process is also beneficial for its excellent electrochemical property.This study not only improved the electrochemical properties by anneal process,but also revealed the origins and mechanisms for its improvement.

Investigation into microstructure of spray formed V4 cold working mould steel and its roiling and annealing

The material selected for this work was the spray formed Vanadis4 high alloy cold working mould steel （abbreviated to V4 steel）. Its microstructure, hot rolling process, and annealing treatment have been investigated. Observed from the optical and electron microscopes, the as-sprayed V4 steel had the finer microstructure of uniform and equiaxial grains ,while after hot rolling for densification and spheroidized annealing, the V4 steel obtained an excellent spheroidized structure that is favorable to subsequent quenching and tempering treatment. The spheroidized structure and level of annealed hardness of the V4 steel are almost the same as expensive imported powder metallurgy the V4 steel. It is difficult to produce V4 steel with the conventional ingot metallurgical technique, so the multi-step and high-cost powder metallurgy method is generally used at present. Compared to the powder metallurgy technique, using the spray forming technique to produce the V4 steel has obvious advantages and potential market competitiveness in reducing production costs, simplifying working process, and shortening the production cycle.

Infrared studies of oxygen-related complexes in electron-irradiated Cz-Si

This paper investigates the infrared absorption spectra of oxygen-related complexes in silicon crystals irradiated with electron （1.5 MeV） at 360 K.Two groups of samples with low [Oi] = 6.9 x 10^17 cm^-3 and high [Oi] = 1.06 x 10^18 cm^-3 were used.We found that the concentration of the VO pairs have different behaviour to the annealing temperature in different concentration of oxygen specimen,it is hardly changed in the higher concentration of oxygen specimen.It was also found that the concentration of VO2 in lower concentration of oxygen specimen gets to maximum at 450 ℃ and then dissapears at 500 ℃,accompanied with the appearing of VO3. For both kinds of specimens,the concentration of VO3 reachs to maximum at 550 ℃ and does not disappear completely at 600 ℃.

Fabrication and characterization of Al–Mn superconducting films for applications in TES bolometers

Superconducting transition edge sensor(TES)bolometers require superconducting films to have controllable transition temperatures T_(c)in different practical applications.The value of T_(c)strongly affects thermal conductivity and thermal noise performance of TES detectors.Al films doped with Mn(Al-Mn)of different concentrations can accomplish tunable T_(c)A magnetron sputtering machine is used to deposit the Al-Mn films in this study.Fabrication parameters including sputtering pressure and annealing process are studied and their influences on T_(c)and superconducting transition widthΔT_(c)are optimized.The Al-Mn films withΔT_(c)below 1.0 mK for T_(c)in a range of 520 mK-580 mK are successfully fabricated.

Distributed cooperative task planning algorithm for multiple satellites in delayed communication environment

Multiple earth observing satellites need to communicate with each other to observe plenty of targets on the Earth together. The factors, such as external interference, result in satellite information interaction delays, which is unable to ensure the integrity and timeliness of the information on decision making for satellites. And the optimization of the planning result is affected. Therefore, the effect of communication delay is considered during the multi-satel ite coordinating process. For this problem, firstly, a distributed cooperative optimization problem for multiple satellites in the delayed communication environment is formulized. Secondly, based on both the analysis of the temporal sequence of tasks in a single satellite and the dynamically decoupled characteristics of the multi-satellite system, the environment information of multi-satellite distributed cooperative optimization is constructed on the basis of the directed acyclic graph（DAG）. Then, both a cooperative optimization decision making framework and a model are built according to the decentralized partial observable Markov decision process（DEC-POMDP）. After that, a satellite coordinating strategy aimed at different conditions of communication delay is mainly analyzed, and a unified processing strategy on communication delay is designed. An approximate cooperative optimization algorithm based on simulated annealing is proposed. Finally, the effectiveness and robustness of the method presented in this paper are verified via the simulation.

Cube texture formation of Ni9.3W alloy substrates:preparation by optimized deformation sequence and anneal process

The Ni9.3W alloy with no ferromagnetism and high yield strength is one of the most promising textured substrate materials for coated conductors, but its low stacking fault energy makes it difficult to obtain a strong cube texture by traditional rolling methods and recrystal- lization anneals. This paper introduces four-time static recoveries during the rolling process. Rolled tapes with 80 μm in thickness were obtained by applying various deformation sequences between static recoveries to study their effects on the cube texture formation in Ni9.3W alloy substrates. The results show that rising gradient deformation sequence is an advantageous way to obtain a higher amount of cube texture, its content increases by 29.2% compared to that of traditional deformation sequence. The effect of the new recrystallization annealing process on the cube texture formation was analyzed. It is shown that the cube texture content increases with anneal temperature increasing in one-step anneal, but decreases again at higher anneal temperature. Two-step anneal could effectively improve the cube texture content, which could be further enhanced by extending holding time during the first-step anneal. However, too long holding time leads to the decrease in cube texture content. Finally, Ni9.3W alloy substrates with a cube texture content of -90.0 vol% （〈15°） are obtained by optimized two-step anneal.

Mach-Zehnder Interferometer for High Temperature(1000℃)Sensing Based on a Few-Mode Fiber

A Mach-Zehnder interferometer(MZI)for high temperature(1000°C)sensing based on few mode fiber(FMF)was proposed and experimentally demonstrated.The sensor was fabricated by fusing a section of FMF between two single-mode fibers(SMFs).The structure was proven to be an excellent high temperature sensor with good stability,repeatability,and high temperature sensitivity(48.2 pm/C)after annealing process at a high temperature lasting some hours,and a wide working temperature range(from room temperature to 1000 C).In addition,the simple fabrication process and the low cost offered a great potential for sensing in high temperature environments.

Highly precise Ti/Pt/Cr/Au thin-film temperature sensor embedded in a microfluidic device

A multilayer(Ti/Pt/Cr/Au)resistive temperature sensor was proposed and investigated to precisely measure the temperature characteristic in microfluidic devices.The Ti/Pt/Cr/Au sensor was fabricated by direct current(DC)sputtering,vacuum evaporation and liftoff process.The thermal annealing test was conducted in the temperature range of 200-800℃for obtaining an appropriate property of the multilayer.Based on the experimental results,400℃was selected as the experimental annealing temperature for the Ti/Pt/Cr/Au layer.The redistribution of structural imperfections and recrystallization promote the density and adhesion of multilayer during the annealing process.With the annealing temperature rising,the annealing process leads to through-thickness migration of chromium and partial depletion of the adhesive layer.The Ti also diffuses into the Pt,which makes the interface disappear.Nevertheless,the layer remains continuous.The temperature coefficient of resistance(TCR)of the sensors was investigated through the microfluidic testing system.The excellent stability and sensitivity of the Ti/Pt/Cr/Au thin-film temperature sensor are verified.Furthermore,the capability of the Ti/Pt/Cr/Au thin-film temperature sensor detecting the sudden temperature change caused by bubble effect is very meaningful to the microfluidic devices.

Characterization of Micro and Nano-Scaled Co/Ni Bi-Layered Films Electrodeposited Under Influence of Magnetic Field:Effects on Structure and Morphology

In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.