喷射沉积7075A1／SICp铝基复合材料板材的高温拉伸变形行为

当温度为300-450℃，应变速率为0．001-0.1S^-1时，在WDW-E200拉伸机上采用单向拉伸实验研究喷射沉积7075A1／SIC。复合材料板材的高温变形行为；分析板材的变形激活能以及流变应力、变形温度和应变速率之间的关系。结果表明：随着变形温度升高和应变速率降低，7075AI／SiCp复合材料板材拉伸流变应力减小；其最大拉伸断裂伸长率由5．03％增加到71．07％；7075A1／SICp复合材料板材应变速率敏感系数的最大值仅为0．22，在温度为623、673和723K时其变形激活能分别为380．49、323．42和434．S6kJ／mol，均高于铝的晶格自扩散激活能（142kJ／mol）。     

喷射沉积7075Al/SiCp铝基复合材料板材的高温拉伸变形行为

当温度为300～450℃,应变速率为0.001～0.1 s-1时,在WDW-E200拉伸机上采用单向拉伸实验研究喷射沉积7075Al/SiCp复合材料板材的高温变形行为;分析板材的变形激活能以及流变应力、变形温度和应变速率之间的关系.结果表明:随着变形温度升高和应变速率降低,7075Al/SiCp复合材料板材拉伸流变应力减小;其最大拉伸断裂伸长率由5.03%增加到71.07%;7075Al/SiCp复合材料板材应变速率敏感系数的最大值仅为0.22,在温度为623、673和723 K时其变形激活能分别为380.49、323.42和434.56 kJ/mol,均高于铝的晶格自扩散激活能(142 kJ/mol).     

TiBw与TiCp原位增强钛复合材料的高温蠕变特性

分别对增强相体积分数为15%的TiBw/Ti和（TiBw TiCp）/Ti复合材料及相应的基体在798-848K范围内进行了蠕变行为研究，结果表明，两种复合材料的应力因子分别为4.6-4.7和4.3-4.5，激活能为294和343kJ/mol，比纯钛的昌格扩散激活能高，两种复合材料的抗蠕变能力均比基体好，而（TiBw TiCp)/Ti的抗蠕变性能比TiBw/Ti还要好，此外，实验表明在三种材料中都没有门槛应力存在，两种复合材料的蠕变机制均为位错攀移机制。     

搅拌铸造工艺制备Mg_2B_2O_5/AZ63B镁基复合材料的热变形行为

在变形温度为250~400℃,应变速率5×10-5~0.5 s~(-1)范围内,研究了均匀化热处理态Mg_2B_2O_5/AZ63B镁基复合材料的热压缩变形行为,并利用双曲线正弦函数建立了其本构方程。结果表明:复合材料的峰值应力及其对应的应变均随温度的降低及应变速率的增加而增大;计算峰值应力与实验值的比较表明双曲正弦函数可以准确描述复合材料的本构关系;复合材料的应力指数n和激活能Q分别为5.5和221 kJ/mol,其变形机制为晶格扩散控制的位错攀移机制。热挤压试验表明:经过均匀化热处理,复合材料的最大及稳态挤压力与铸态相比分别下降了92 kN和80 kN。     

一种钛基复合材料的热变形本构模型

在Gleeble-1500热模拟试验机上进行热压缩试验.研究了变形温度为900～1150℃、应变速率为0.001～10 s~(-1)时TiC颗粒增强钛基复合材料的热变形行为,根据所得应力应变曲线分析了该合金的热变形特征,并采用双曲正弦模型建立了该钛基复合材料的本构关系.计算了α+β区域的平均变形激活能为691 kJ/mol,β区域平均变形激活能为202 kJ/mol.     

热压缩条件下V-5Cr-5Ti合金的热激活参数

为了了解V?5Cr?5Ti合金(质量分数)热加工过程的基本物理机制，在Gleeble-3800热物理模拟试验机上采用热压缩方法测量合金在1373~1673 K范围内的热激活参数。结果表明：抛物线型本构方程的应力指数n和激活能Q分别为4.87和375.89 kJ/mol。通过引入临界应力参数(σ0)，计算得到的激活能Q为288.34 kJ/mol，这与合金的自扩散激活能(270~300 kJ/mol)相近。重复应力松弛实验得到合金的物理激活体积Vp和应变速率敏感指数m分别为(120~700)b3和0.075~0.122。上述激活参数表明：V?5Cr?5Ti合金在1373~1673 K和0.001~1.0 s?1范围内的热压缩物理机制为克服林位错钉扎的位错攀移。     

Sc掺杂TiB2/6061复合材料热变形行为及热加工图

采用Gleeble-3800热模拟试验机对0.2%Sc-2%TiB₂/6061复合材料进行热压缩实验，研究了该材料在变形温度为623～773 K、应变速率为0.001～1 s^-1条件下的热变形行为，基于应力应变曲线，构建了材料的本构方程及热加工图。结果表明：0.2%Sc-2%TiB₂/6061复合材料的流变应力随变形温度的升高和应变速率的降低而降低，材料的热变形激活能为227.751 kJ/mol；在热压缩过程中，失稳区主要出现在高应变速率区域(663～773 K,0.132～1 s^-1)及低温区域(623～655 K,0.001～0.040 s^-1)，最优的热加工区域为变形温度703～773 K、应变速率0.017～0.107 s^-1。热变形过程中该材料的软化机制主要为动态回复。     

热压缩条件下V-5Cr-5Ti合金的热激活参数（英文）

为了了解V-5Cr-5Ti合金(质量分数)热加工过程的基本物理机制,在Gleeble-3800热物理模拟试验机上采用热压缩方法测量合金在1373~1673K范围内的热激活参数。结果表明:抛物线型本构方程的应力指数n和激活能Q分别为4.87和375.89kJ/mol。通过引入临界应力参数(σ_0),计算得到的激活能Q为288.34 kJ/mol,这与合金的自扩散激活能(270~300kJ/mol)相近。重复应力松弛实验得到合金的物理激活体积V_p和应变速率敏感指数m分别为(120~700)b~3和0.075~0.122。上述激活参数表明:V-5Cr-5Ti合金在1373~1673K和0.001~1.0s~(-1)范围内的热压缩物理机制为克服林位错钉扎的位错攀移。     

Ti53311S钛合金的热变形和加工图

用Gleeble-1500对Ti53311S钛合金在温度为880-1080℃，应变速率为0．001～10s^-1。最大变形量为80％的条件下进行高温压缩变形行为研究。测试了其真应力一真应变曲线，建立了本构方程，并求出变形激活能。双相区为377kJ／mol，β相区为648kJ／mol。并观察了变形后的显微组织，计算分析了该合金的加工图。结果表明：该合金对温度和应变速率敏感，不同变形条件下的应力值变化很大；应变速率敏感指数随温度的升高而降低．而变形激活能随温度的升高而增大。合金的变形机理主要为动态再结晶和动态回复。Ti53311S钛合金加工过程中温度应控制在相变点以下，应变速率应控制在0．01s^-1以上、10s^-1以下为宜。     

热变形TiAl基合金的超塑性行为

采用包套锻复合热机械处理技术,在Ti-33Al-3Cr合金中得到了平均名义晶粒尺寸为1μm的热变形显微组织材料在1000—1075℃及10×10－6—8×10－3S－1的应变速率范围内显示良好的超塑性,其应变速率敏感系数高达0．9;热激活能仅为250kJ／mol．在1075℃及8×10－5s－1下得到517％的超塑性拉伸延伸率．获得高的超塑性拉伸值的机理是,动态再结晶导致应变速率硬化     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

THERMODYNAMICS STUDY ON THE DECOMPOSITION OF CHROMITE WITH KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

INFLUENCE OF HEAT TREATMENT ON DAMPING BEHAVIOUR OF THE MAGNESIUM WROUGHT ALLOY AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.     

An Easy Way to Quantify the Adhesion Energy of Nanostructured Cu/X(X=Cr,Ta,Mo,Nb,Zr) Multilayer Films Adherent to Polyimide Substrates

An approach based on film buckling under simple uniaxial tensile testing was utilized in this paper to quantitatively estimate the interfacial energy of the nanostructured multilayer films(NMFs) adherent to flexible substrates. The interfacial energies of polyimide-supported NMFs are determined to be *5.0 J/m2 for Cu/Cr, *4.1 J/m2 for Cu/Ta,*2.8 J/m2 for Cu/Mo, *1.1 J/m2 for Cu/Nb, and *1.2 J/m2 for Cu/Zr NMFs. Furthermore, a linear relationship between the adhesion energy and the interfacial shear strength is clearly demonstrated for the Cu-based NMFs, which is highly indicative of the applicability and reliability of the modified models.     

High-Speed Friction Stir Welding of SiC_p/Al–Mg–Si–Cu Composite

A 17 vol% SiCp/Al–Mg–Si–Cu composite plate with a thickness of 3 mm was successfully friction stir welded(FSWed) at a very high welding speed of 2000 mm/min for the first time. Microstructural observation indicated that the coarsening of the precipitates was greatly inhibited in the heat-affected zone of the FSW joint at high welding speed, due to the significantly reduced peak temperature and duration at high temperature. Therefore, prominent enhancement of the hardness was achieved at the lowest hardness zone of the FSW joint at this high welding speed, which was similar to that of the nugget zone. Furthermore, the ultimate tensile strength of the joint was as high as 369 MPa, which was much higher than that obtained at low welding speed of 100 mm/min(298 MPa). This study provides an effective method to weld aluminum matrix composite with superior quality and high welding efficiency.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.