热轧态Si—Mn系双相钢的组织转变

利用Ｇｌｅｅｂｌｅ－１５００热模拟试验机对试验钢进行了热模拟轧制。研究了在不同热轧工艺参数与合金化程度条件下Ｓｉ－Ｍｎ双相钢的组织转变。获得了估算热轧态Ｓｉ－Ｍｎ双相钢马氏体体积百分数和先共翁素体体积百分数的计算式。计算值与实测值相吻合，给出了ｆｍ－Ｔ－Ｖ和ｆＦｐ－Ｔ－Ｖ关系的三维图及相应的ｆＭ和ｆＦｐ等值线图。     

氧化钒制取碳化钒的热力学分析

采用热力学的方法对以五氧化二钒为原料制取碳化钒的工艺过程进行了分析,分析表明:钒氧化物的转化过程中遵守逐级还原理论。钒氧化物碳化过程中,不转化为金属钒,直接转化为碳化钒。在钒氧化物的转化过程中,应尽可能使其转化为二氧化钒。若采用气相还原碳化的方法,可通过调节气体的流量、配比、还原与碳化工艺参数进行质量控制。     

Microhardness and corrosion behavior in CrN/electroless Ni/mild steel complex coating

The electroless nickel–phosphorous (Ni–P) coating was chosen as an interlayer to improve the properties of the CrN/mild steel (MS) composite. A hypophosphite-reduced acid solution was used to first deposit electroless Ni–P onto MS substrates, and then the CrN overlayer was deposited by reactive r.f. magnetron sputtering onto the electroless Ni–P modified substrate. The electroless Ni–P layer crystallizes with the precipitation of a Ni₃P phase during r.f. sputtering, and thus a coating–substrate composite of CrN/Ni–Ni₃P/MS is formed. The electroless Ni–P coating increases the surface hardness of the steel substrate to more than three times. The surface hardness of the CrN coating modified by an electroless Ni–P interlayer exhibits a hardness higher than 2000 HK_0.015. The usual substrate effect on the microhardness of the coatings is nearly eliminated with the complex coating feature, and a significant enhancement of surface hardness in the coating assembly is achieved. The corrosion tests indicate that the Ni–Ni₃P/MS configuration exhibits a more positive E_corr value (i.e. less electronegative) than CrN/MS and the corresponding potential curve is shifted toward the low-current side, indicating a better anti-corrosion performance. Through comparison of the E_corr values and the polarization curves, it is demonstrated that the CrN/Ni–Ni₃P/MS composite exhibits significantly higher corrosion resistance than the Ni–Ni₃P/MS and CrN/MS coating configurations.     

含钴锆基块状非晶合金的制备与力学性能

采用水淬法制备了Zr—Ti—Cu—Ni—Be—Co块状非晶合金(BMGs)。使用XRD进行相分析，采用热分析仪进行玻璃转变温度、晶化温度和热稳定性等的测定，用SEM观察试样压缩后的外表面和断口形貌。研究了Co对Zr—Ti—Cu—Ni—Be合金非晶形成能力(GFA)、热稳定性及力学性能的影响。结果表明：含Co的所有Zr—Ti—Cu—Ni—Be BMGs都有1个明显的玻璃转变点和宽的过冷液相区(△T）。Zr38Ti17Cu10.5Co12Be22.5合金具有和Zr41Ti14Cu12.5Ni10Be22.5合金相当的△T；Co的添加明显提高Zr—Ti—Cu—Ni—Be BMGs的力学性能，含Co量大于10at％的Zr—Ti—Cu—Ni—Be BMGs的压缩断裂强度（σf）超过2000MPa，Zr38Ti17Co22.5Be22.5合金的σf达到2230MPa，比Zr41Ti14Cu12.5Ni10Be22.5合金的σf提高23％。     

CO2气体保护的激光焊接12mm厚低碳钢板

采用CO2 作为保护气体消除大熔深激光焊接低碳钢时易发生的气孔问题 ,并对比研究了CO2 和Ar气保护条件下 12mm厚低碳钢板激光焊缝的组织和韧性。焊接试验利用 4kWNd :YAG激光器 ,采用双面深熔焊的方法 ,焊接条件为 4kW激光功率和0 .3 ,0 .5m/min的焊接速度。冲击试验采用一种自行设计的带侧面缺口的三缺口冲击试样 ,以保证断裂全部发生在焊缝。结果表明 ,利用CO2 作保护气体焊接低碳钢板 ,可以有效消除大熔深激光焊接时的气孔问题 ,并获得比Ar气保护下硬度较低 ,冲击韧性高的焊缝。研究工作为解决大功率激光深熔焊时容易发生的气孔问题提供了一条有效途径     

电沉积镧镍合金薄膜的电化学贮氢性能研究

利用在水溶液中电沉积的方法制备了LaNi5贮氢合金薄膜。采用XRD方法研究了贮氢合金薄膜在充放电前后相结构的变化，运用扫描电镜观察了合金薄膜的表面形态，通过电化学测试（循环伏安、恒电流充放电）研究其电化学贮氢性能。结果表明，该合金薄膜具有较好的电化学贮氢性能，电化学活性较高，无需活化过程，最高电化学容量可达156mAh／g。     

应用人工神经网络理论建立热粘塑性材料的本构关系

本文将人工神经网络（ＡＮＮ）用于建立热粘塑性材料的本构关系，意在探索出一种描述材料变形力学行为的新方法。文中给出了应用人工神经网络建立热粘塑性材料本构关系的ＢＰ模型和学习算法过程，并应用于４５号钢在高温和高速变形条件下的流动应力计算。计算结果与实测结果比较表明，二者吻合良好。因此，应用人工神经网络建立热粘塑性材料的本构关系具有重要的工程应用价值。     

Novel Mo-V Oxide Catalysts with Nanospheres as Templates for the Selective Oxidation of Acrolein to Acrylic Acid

Catalysis Letters - Novel Mo-V-PMMA and Mo-V-PS catalysts are prepared by addition of hard polymethyl methacrylate (PMMA) and polystyrene (PS) nanospheres into Mo/V compounds in the preparation...     

PVP-assisted Sn-Ti microspheres for the efficient B–V oxidation of cyclohexanone

Journal of Porous Materials - New Sn-Ti microspheres were first successfully synthesized by a PVP-assisted sol-gel method in this paper, and their performance in the B–V oxidation of...     

Facile synthesis of nitrogen and oxygen co-doped hierarchical porous carbon materials for high performance super capacitors

Journal of Porous Materials - Nitrogen and oxygen co-doped hierarchical porous carbons (NOPCs) is prepared by the pyrolysis of polyethylene glycol-200 (PEG) and triazine carbon forming agent (CFA)...