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.

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.

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.

Transient numerical simulation of annealing process in a conjugate combined radiation conduction heat transfer

The annealing time is an important affecting factor in the performance of many furnaces.The present work deals with the transient simulation of annealing process in a cubic furnace in which a solid element is placed in its center.As the working gas can have some radiating features,a set of governing equations including the energy balance with the radiative transfer equation(RTE)for the gray radiating medium and the conduction equation inside the solid product are numerically solved with progressing in time.Numerical results which are validated against both analytical and theoretical findings in the literature demonstrate that during the starting period,a high rate of radiant energy transfers into the solid body even at small optical thickness.This behavior which hastens the rate of heat transfer at low values of the radiation conduction parameter,causes a fast annealing process in which the solid body warms up to its maximum temperature.Moreover,it is revealed that the rate of heat transfer is an increasing function of radiation-conduction parameter.

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.

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 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.

Water-based processed and alkoxide-based processed indium oxide thin-film transistors at different annealing temperatures

In this study,indium oxide（In2O3） thin-film transistors（TFTs） are fabricated by two kinds of low temperature solution-processed technologies（Ta ≤ 300℃）,i.e.,water-based（DIW-based） process and alkoxide-based（2-ME-based）process.The thickness values,crystallization properties,chemical structures,surface roughness values,and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures.Thermal annealing at higher temperature leads to an increase in the saturation mobility（μsat） and a negative shift in the threshold voltage（VTH）.The DIW-based processed In2O3-TFT annealed at 300℃ exhibits excellent device performance,and one annealed at 200℃ exhibits an acceptable μsat of 0.86 cm^2/V·s comparable to that of a-Si：H TFTs,whereas the 2-ME-based TFT annealed at 300℃ exhibits an abundant μsat of 1.65 cm^2/Vs and one annealed at 200℃ is inactive.The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature.The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic,low-cost,and low-temperature oxide electronics.

Effects of annealing treatments on forming performance of zirconium alloys

The effects of annealing treatments(ATs)on the microstructure of Zr-Sn-Nb alloy strips were studied.Based on the characteristics of strips for nuclear fuel assemblies,punching experiments were carried out and the formability of zirconium alloy strips was quantitatively evaluated.The results indicate that the proportions of small-angle grain boundaries of the zirconium alloy under conditions of annealing treatment at 580°C(ATⅠ)and annealing treatment at 620°C(ATⅡ)are 14.3%and 23.2%,respectively,while that of the as-received material is 12.4%.And the forming limit margin fields of the zirconium alloy under ATⅠcan reach 0.43%,while the values of the as-received material and the ATⅡare-0.35%and-2.8%,respectively.The annealing process affects the evolution process of the strip recrystallization texture and the grain size.Moreover,the total texture and pole density are closely related to the degree of anisotropy of the strip.Besides,the small-angle grain boundary affects the strain path and crack expansion of the necking unit during the strip punching process,while the grain size affects the hardening exponent of the material.

Microstructure and Property of Al‑FeCoNiCrAl High Entropy Alloy Composite Coating on Ti‑6Al‑4V During Annealing Using MA Method

Al-FeCoNiCrAl high entropy alloy(HEA) composite coatings were prepared on Ti-6Al-4V via highenergy mechanical alloying(MA). The microstructures and phase composition of the coatings were studied. A continuous and dense coating could be fabricated at a ratio of 35%(weight fraction)Al-FeCoNiCrAl after 4 h milling.The results showed that the thickness of the composite coatings increased first and then decreased with the increase of milling time. And the hardness of coating increased with the increase of milling time. The phase changed during the annealing process. Part of the initial body-centered cubic(BCC)phase of the composite coatings changed into the L12 phase,(Ni,Co)3Al4 and σ phase after annealing above 550 ℃. Ordered BCC was found in the coatings after annealing above 750 ℃. Only BCC and ordered BCC appeared in coatings after annealing above 1 050 ℃. The hardness of the coatings after annealing at 550 ℃ and 750 ℃ was higher than before because of spinodal decomposition and high hardness σ phase. The hardness of the coatings after annealing at 1 050 ℃ decreased because residual stress released.

Effect of annealing parameter on microstructure and magnetic properties of cold rolled non-oriented electrical steel

The microstructure and magnetic properties of cold rolled non-oriented electrical steel,annealed at 200-1 000 ℃ for 0-240 min with different heating rates,were investigated by optical microscopy,scanning electron microscopy,Epstein frame,and transmission electron microscopy. The results show that the magnetic properties of cold rolled non-oriented electrical steel can be improved by controlling the annealing process to obtain uniform coarse grains with critical sizes after the recovery,recrystallization and growth of grains. Additionally,the annealing temperature influences the magnetic properties more significantly than annealing time,and with the increase of heating-up rate during the annealing process,the magnetic properties of the cold rolled non-oriented electrical steel increase.

Structures and properties of deformation-processed Cu-16Fe-2Cr in-situ composites

Microstructure and properties of deformation processed Cu 16Fe 2Cr and Cu 18Fe in situ composite wires obtained by cold drawing combined with intermediate annealing were investigated. At lower strains( η <2.52), most of the Fe(Cr) phases were elongated into filaments except some remain granular because of their higher hardness. The ultimate tensile strengths of Cu 16Fe 2Cr and Cu 18Fe are approximately equal at the same drawing strains, suggesting the increase of strength of Cu 16Fe 2Cr due to higher strength of Fe(Cr) filaments than that of Fe filaments which is counteracted by the somewhat coarse Fe(Cr) filaments in Cu 16Fe 2Cr at the same drawing strains. The increase of the electrical conductivity of Cu 16Fe 2Cr and Cu 18Fe after intermediate annealing is attributed to the precipitation of Fe, Cr atoms, which dissolved during melting processing. Electrical conductivity of the Cu 16Fe 2Cr in situ composites is higher than Cu 18Fe in situ composites at the same drawing strains. The addition of Cr to Cu Fe system can increase mechanical stability of the filaments in the composites.

Structural transformation of FePt nanocomposite films during annealing and its effects on magnetic properties

Fe100-xPtx(x=30at.%-60at.%) nanocomposite films were deposited on natural-oxidized Si(100) substrates by magnetron sputtering. The as-deposited films were annealed between 373 and 1073 K. In situ X-ray diffraction shows that the FePt nanocomposite films undergo a phase transformation from a disordered FCC phase to an ordered L10 phase between 673 and 773 K. The coercivity is 306 kA·m-1 whiles the average grain sizes is about 10 nm in the optimized FePt alloy film sample annealed at 673 K. The adjustable coercivity and fine grain size suggest that this FePt nanocomposites system is suitable as recording media at extremely high areal density.

Comparative Study of Earing Behavior in Cold Rolled-batch Annealed and Cold Rolled-Continuous Annealed of DoubleReduced (DR) Tinplate Steels

Two double cold reduction-drawn and redrawn(DRD) tinplate steels of the same chemistries that have been processed by continuous and batch annealing line have been researched. The composition of fibers were studied through X-ray diffraction. The results indicate that a strong intensity of {114}<110> was formed in the continuous annealing steel and a strong intensity of {111}<112> was formed in the batch annealing steel; not only that but the γ fiber slowly rotated to the low angel α fiber with the angel being about 30° nearly {112}<110>texture owing to the higher second reduction.

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.

退火工艺对Ti-Ni-V形状记忆合金相变和形变行为的影响

利用差示扫描量热仪和拉伸试验研究了400℃×10~120 min和500℃×10~120 min退火态Ti-50.8Ni-0.5V合金的相变行为、拉伸性能和形状记忆行为。结果表明:随退火温度和时间变化,合金的相变类型、R相变温度T_(R)和热滞ΔT_(R)、马氏体相变温度T_(M)和热滞ΔT_(M)、抗拉强度R_(m)、伸长率A、应力诱发马氏体相变临界应力σ_(M)、加载-卸载残余应变ε_(R)和能耗W_(D)的变化规律如下:400和500℃退火态Ti-50.8Ni-0.5V合金皆发生B2→R→B19’/B19’→R→B2(B2-母相,CsCl型结构;R-R相,菱方结构;B19’-马氏体相,单斜结构)型相变;T_(R)^(400℃)>T_(R)^(500℃),T_(M)^(500℃)>T_(M)^(400℃),ΔT_(M)^(400℃)>ΔT_(M)^(500℃)≥ΔT_(R)^(400℃)≈ΔT_(R)^(500℃)≈4℃;R_(m)^(400℃)>R_(m)^(500℃),A^(500℃)>A^(400℃);400℃退火态合金的超弹性(SE)稳定性高于500℃退火态合金。随退火时间延长,T_(R)^(400℃)、T_(R)^(500℃)、T_(M)^(400℃)和T_(M)^(500℃)升高,ΔT_(M)^(400℃)和ΔT_(M)^(500℃)减小,ΔT_(R)^(400℃)和ΔT_(R)^(500℃)在3.5~4.6℃之间变化;400℃退火态合金保持SE,500℃退火态合金由SE向SE+SME(形状记忆效应)转变;σ_(M)^(400℃)和σ_(M)^(500℃)降低;W_(D)^(400℃)和W_(D)^(500℃)增加;ε_(R)^(500℃)先降后升;ε_(R)^(400℃)在0.64%~1.36%之间变化。要使Ti-50.8Ni-0.5V合金获得较高的T_(R),可对其进行400℃退火;要使该合金获得较高的T_(M),可对其进行500℃退火;要使该合金在室温下获得超弹性,可对其进行400℃×10~120 min或500℃×10~60 min退火。

A Generic MEMS Fabrication Process Based on a Thermal Budget Approach

A modular and generic monolithic integrated MEMS process for integrating CMOS technology with polysilicon microstructures is presented. The proposed process flow is designed with an intra CMOS approach to fabricate the microstructures into trenches without the need of planarization techniques. After annealing at 1000°C at significant period of time, it is shown that Id-Vg characteristics of the CMOS transistors remain almost unchanged, indicating their robustness to the intra process fabrication for the micromechanical structures. The CMOS module is designed with a 3 μm length as a minimum feature and this process results with a minimum of residual strain and stress on the micromechanical devices (ε = 1.28 × 10-4 and σ = -21 MPa).

聚碳酸酯气体辅助注射成型制品内应力分布及改善工艺

聚碳酸酯(PC)注塑制品出模后在无外加约束条件下内部应力得不到松弛释放,易导致制品产生开裂,严重影响制品的服役性能。为探究PC制品内应力分布规律,找到有效降低内应力的工艺措施,基于气体辅助注射成型(GAIM)工艺和自行设计制造的带有半圆形加强筋的平板试验模具,结合光弹法和溶剂检测法,研究GAIM制品内应力的分布特点,讨论注气压力和气体保压压力两种工艺参数对GAIM制品内应力的影响规律,提出两种改善制品内应力的工艺方法。研究发现:通过光弹法观测到的应力条纹分布与溶剂浸泡后的裂纹开裂区域一致,即GAIM制品末端及边缘处内应力较大,沿气道两侧应力分布较均匀;较高的注气压力和较低的气体保压压力可以更加有效减小GAIM制品的内应力;通过对GAIM制品24 h即时退火和延长二次注气的卸压时间可以有效降低制品内应力。