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Abstract:With the development of numerical technique and computer technology, the numerical modeling of the solidification process is changing from macro to micro modeling. By micro modeling not only the solidified microstructure of materials can be predicted, but also the accurate information of latent heat releasing can be provided for the macro modeling. The complete coupling of macro and micro modeling can result in a more accurate prediction for the solidification process of casting alloys. In the paper the state of art of the microstructure simulation was given in order to describe the main methods of micro modeling, such as deterministic, stochastic and phase field modeling, etc. Because of the complexity of numerical simulation of the solidification microstructure, it is necessary to study deeply the microstructure simulation, which would be the important research orientation in the field of computational materials science. Finally, the existent problem and the future developing orientation were analyzed.

Abstract:Two kinds of cryomilling mills have been introduced. The current status of research of cryomilling has been briefly reviewed. The applications for nm scaled materials with high thermal stability are especially emphasized. The mechanism of alloying for cryomilling and the stability at elevated temperature are discussed. The future trend of cryomilling is presented.

Abstract:On basis of the internet resources, The concept and the processing of DU metal were introduced, including the physical and chemical properties and their applications in variety of fields. Specially the structures and characters of DU penetrators were described in detail. The aftermath of radiative pllution brought by DU on the warfield and force crew was discussed thoroughly. The unsolved problems of DU munitions and its development prospect were also presented.

Abstract:用掃描探針顯微鏡(SPM)研究了Zr—4合金在高壓釜中經(jīng)360℃高溫水腐蝕后氧化膜中的顯微組織和晶粒形貌。從氧化膜表面上觀察到的晶粒在100nm～400nm之間，比從截面上觀察到的大，說明氧化膜的晶粒在腐蝕過程中仍在不斷長大。從離子轟擊蝕刻后的氧化膜截面上，可以區(qū)分出由大角度晶界構(gòu)成的柱狀晶，以及在柱狀晶中由小角度晶界構(gòu)成的等軸晶。在三晶交界處，常常有明顯的“凹陷”，這應(yīng)是空位擴(kuò)散凝聚后形成的空洞，尺度在幾納米至幾十納米間。在氧化膜的截面上，除了可觀察到裂紋和空洞等缺陷外，在氧化膜／金屬交界處，有時(shí)還可觀察到片層狀的氫化鋯和顯示不出晶界的非晶ZrO2。

Abstract:通過化學(xué)鍍方法制備了Ni—B合金涂層。經(jīng)DSC和XRD分析確認(rèn)該合金涂層在0℃～500℃之間有3種相變發(fā)生，分別形成不同種類的鎳硼化合物。涂層硬度也因鎳硼化合物種類不同而變化。特定的處理工藝使涂層顯微硬度(HV)高達(dá)15000MPa以上。用原子力顯微鏡(AFM)對(duì)涂層表面觀察發(fā)現(xiàn)，不同熱處理的該合金涂層表面形態(tài)不同。表面形態(tài)的差異對(duì)涂層的硬度有影響。特別是當(dāng)涂層中出現(xiàn)粒徑為40nm～100nm、高度為10nm～20nm的突起物時(shí)，涂層的硬度會(huì)大幅提高，并對(duì)硬度提高的機(jī)制作了討論。

Abstract:A ruthenium oxide coated activated carbon (RuO2/C) was synthesized as a new electrode material for aqueous electrolyte super capacitor. Some laboratory scale prototype capacitors were fabricated with the RuO2/actived carbon electrode material and tested in term of capacitance and high power discharge for their electrochemical performance.These composite super capacitors exhibited a satisfactory performance,such as the rated capacitance higher than 350 F/g,compared with that of single electrode material only.

Abstract:T1(Al2CuLi)相是Al-Li-Cu-Zr合金中的重要強(qiáng)化相.通過TEM在對(duì)T1相結(jié)構(gòu)和形貌分析的基礎(chǔ)上,構(gòu)造了T1相的結(jié)構(gòu).T1相晶核以ABCBA的堆垛順序,共由36個(gè)原子組成,其晶格常數(shù)a=0.495nm,c=0.933nm.與基體的位相關(guān)系為{0001}T1∥{111}α,<>T1∥<110>α.合金中銅原子的偏聚降低了基體的層錯(cuò)能,從而為T1相依賴擴(kuò)散層錯(cuò)形核提供了有利條件.T1相長大依賴于原子擴(kuò)散和臺(tái)階滑移,是一種長程擴(kuò)散控制的臺(tái)階機(jī)制.

Abstract:The bonding strength of hydroxyapatite(HA)/Ti FGM implants fabricated by powder metallurgy was investigated by means of the in vivo implanting in rabbits and the shear strength testing. It was shown that the HA/Ti FGM possess a good biocompatibility and osteoconductivity, and can be integrated with bone. After implanted for three months, the FGM implants and the new bone formed around became one bony body. The bonding strength between FGM implants and the surrounding bone tissues raises quickly with increasing the implanting time, and can reach 6.49MPa after implanted for three months, higher than that of dense pure HA or Ti implants. Fractography observations reveal that the fracture occurred in the new bone near the interface during the shear testing of HA/Ti FGM implants, which indicates that its interfacial bonding strength even exceeds the shear strength of new bone tissues.

Abstract:Stress corrosion crack (SCC) susceptibility of titanium alloy TC4 in methane and hydrochloric acid methane solution was studied by slow strain rate tensile test (SSRT), SEM analysis and metallography observation. The experimental results show that TC4 is possessed of SCC susceptibility in methanol solution, and addition of methanol solution to hydrochloric acid methanol solution can greatly improved the SCC susceptibility of TC4 alloy. SCC of TC4 in hydrochloric acid mdethanol solution originates from the bottom of the corrosion pits.

Abstract:Effective and reasonable computational models are established to simulate the penetrating processes for the tungsten fiber reinforced tungsten alloy matrix composite penetrators and the tungsten alloy penetrators by the DYNA 3D finite element program. The simulation results are compared and verified by the penetrating experiments. The reason that the penetrating performance of the tungsten fiber reinforced tungsten alloy matrix composite penetrator is superior to that of the tungsten alloy penetrator is discussed.These results can provide reliable theory,computational models and experiment bases for further research.

Abstract:The superalloy melt is easily contaminated by the ceramic mold material because the melt is kept in it for long time for the traditional process. By the new electromagnetic soft contact confinement process, the superalloy melt is half suspended by electromagnetic pressure, so the contacting area and time between melt and magnetic mold decrease. Simultaneously, the contamination is decreased effectively. The new technique combines the electromangetic soft contact confinement with directional solidification process for manufacturing the near net shape turbine blade castings of superalloys. The effects of the magnetic mold material and the height and position of susceptor on the magnetic flux density distribution in the inductor were comprehensively investigated. In the experiment, two near net shape blade castings with directionally solidified microstucture are successfully obtained by the electromagnetic soft contact confinement process.

Abstract:在Thermecmaster-Z型熱加工模擬試驗(yàn)機(jī)上對(duì)TC6鈦合金在溫度800℃～1040℃,應(yīng)變速率10s～50s、最大變形程度50%條件下的高溫流動(dòng)應(yīng)力變化規(guī)律進(jìn)行了研究,進(jìn)而分析了變形參數(shù)對(duì)微觀組織的影響。結(jié)果表明合適的工藝參數(shù)是變形溫度為920℃～950℃,應(yīng)變速率為1.0s-1～1×10-3s-1。在變形過程中,變形溫度對(duì)α相體積分?jǐn)?shù)有著顯著影響,應(yīng)變速率對(duì)α相體積分?jǐn)?shù)影響不大,但對(duì)α相晶粒的形態(tài)有一定的影響。最后在分析變形溫度、變形程度和應(yīng)變速率對(duì)流動(dòng)應(yīng)力影響規(guī)律的基礎(chǔ)上提出了1種本構(gòu)關(guān)系模型,其擬合精度較高,為進(jìn)行鈦合金高溫變形過程的數(shù)值模擬打下了較好的基礎(chǔ)。

Abstract:自生顆粒增強(qiáng)鈦基復(fù)合材料中的TiC增強(qiáng)相，可分為初生TiC和共晶TiC，它們的形態(tài)、尺寸及形成機(jī)制均不盡相同。利用SEM、XRD、EDX等手段研究了鈦合金中共晶TiC的形態(tài)及形成機(jī)制。合金中含碳量不同時(shí)，可能形成規(guī)則共晶或離異共晶。成分處于共晶點(diǎn)附近的合金，由于兩相共生生長，β—Ti抑制了TiC的分枝，使TiC呈棒狀或顆粒狀，形成規(guī)則共晶。含碳量遠(yuǎn)低于共晶成分時(shí)易形成離異共晶，共晶反應(yīng)發(fā)生在初生β—Ti枝晶的間隙中，多數(shù)共晶β—Ti依附于初生β—Ti生長，TiC與熔體接觸增多，易分枝，而大量初生β—Ti的存在使TiC分枝受空間限制，只能在二維方向上分枝，從而促使羽毛狀TiC的形成。Mo、Sn等合金元素的加入可使共晶TiC形態(tài)成為球團(tuán)狀。

Abstract:利用超臨界CO2流體萃取技術(shù)從陶瓷注射成型坯體中萃取有機(jī)粘合劑。對(duì)陶瓷注射成型中所使用的有機(jī)載體組分進(jìn)行研究，對(duì)陶瓷注射成型超臨界CO2流體脫脂的工藝條件進(jìn)行了探索，研究了不同萃取壓力，溫度及時(shí)間對(duì)萃取率和陶瓷坯體脫脂質(zhì)量的影響。結(jié)果顯示利用40％～50％(質(zhì)量分?jǐn)?shù)，下同)非極性分子有機(jī)物石蠟(PW)與30％～40％極性分子有機(jī)物聚丙烯(PP)及20％硬脂酸(SA)組成陶瓷注射成型熔體中的有機(jī)載體，在壓力P=30MPa，溫度T=58℃的超臨界CO2流體中脫脂可在較短的時(shí)間內(nèi)獲得無缺陷的陶瓷注射成型生坯。

Abstract:Hydrogen Decrepitation (HD) has been used as an efficient and economical method in producing coarse NdFeB powder. This article studied the effects of hydrogen on the Nd Dy Fe B magnets, such as HD powder oxidation and magnetic performance of sintered magnets. The results showed that the hydrogen accelerated the oxidation of the coarse Nd Dy Fe B powder after HD process, and the dehydrogenated powder had higher oxidation resistance, especially degassed at higher temperature, and the hydrogen dropped the sintering temperature of Nd Dy Fe B magnets. The effects of hydrogen may focus on that hydrogen bonds accelerate absorption of water from ambient air, and the defects caused by hydrogen induce oxygen diffusing more quickly. The magnets could be sintered at a lower temperature with un dehydrogenated HD powder, but had poorer orientation degree.

Abstract:Some new magnetic properties would be produced during processing for the stainless steel fibers. The magnetic parameters had been obtained through a systemic testing and microstructure observation by XRD for the stainless steel fibers. The results showed that the change of composing phases, the internal stress and the microstructure had insignificant effects on the magnetic properties for the stainless steel fibers. It was important to optimize the processing parameters and to expend the application fields for the stainless steel fibers.

Abstract:將水熱合成引入到Pechini方法制得了尖晶石結(jié)構(gòu)的鋰離子電池正極材料LiMn2O4，此方法不但節(jié)省原料，而且工藝簡(jiǎn)單易行。討論了煅燒溫度、粒度和比表面積因素對(duì)LiMn2O4電化學(xué)性能的影響。結(jié)果表明：在煅燒溫度為650℃時(shí)，晶化完全，粒子尺寸適中，初始容量為122mAh／g。

Abstract:Viscosity of Al 16% Si alloys modified by Ce adding with different contents was studied. The results showed that the viscosity increased with the addition of Ce and their content. The variation of liquid structure and the relations between the liquid structure and the viscosity were discussed and analyzed for Al 16% Si alloys according to the variation of the hydrogen content, the solidification structure and the DSC curves.

Abstract:The burned resistant and reliability of initiating arc in GTAW for 1% CeO2 and 2% CeO2 tungsten bar have been compared in this research . It has been suggested that the tungsten bar with 1% CeO2 has a lower burned rate during manufacturing and better electrode performance in GTAW than the 2% CeO_2 tungsten bar .

Abstract:Mean and local residual stresses in Cu films and Ag films on 4Cr13 substrates are evaluated by cantilever beam method. The results show that the mean and local residual stresses in Cu films and Ag films decrease abruptly with the film thickness, then tend to be stable. The residual stress in the two kinds of films mainly originates from the interfacial misfit strain. Their interfacial stress is very large and the growing stress is small. The mean value of residual stress in thin Cu films is very large, even beyond the fracture strength of the bulk Cu material.