Precursor Dependent Structural Phase Evolution in Hydrothermally Prepared Cu<Subscript>2</Subscript>O Octahedrons and Cu Micro-Flakes and Their Structural and Optical Properties

Cuprous oxide (Cu₂O) and metallic copper particles with different microstructures have been prepared by a single-step hydrothermal method by using copper acetate monohydrate and sodium hydroxide as precursors, d-glucose as reducing agent, and poly (vinylpyrrolidone) as stabilizing agent. It was found that the concentration of the NaOH in the reactant solution played a significant role in the structural phase formation of the product. Further, it was also optimized to get either the single phase of Cu₂O or Cu or the mixed phase of Cu₂O and Cu depending on the NaOH content in the reaction mixture. The product material was systematically investigated by x-ray diffraction (XRD), Rietveld refinement, UV–Vis, Raman spectroscopies, scanning electron microscopy (SEM), and X-ray energy dispersive spectroscopy (XEDS). A thorough analysis of the XRD patterns in a standard method as well as by Rietveld refinement have shown the cubic phases for both Cu₂O and Cu. The same phases have been retained in the mixed phase sample also. Optical band gap was determined through Tauc plot to be 1.95 eV. Microstructural studies by SEM showed that the Cu particles were formed as micro flakes whereas the Cu₂O particles were formed with the well-defined octahedral morphology. The XEDS analysis confirmed the chemical composition in Cu₂O. This work reports the dependence of NaOH concentration in the reactant solution on the type of product (single phase or a mixed phases of Cu₂O and Cu) and their structural and optical properties.     

浅谈铜冶炼厂烟囱防腐设计

对铜冶炼厂烟囱烟气腐蚀的成因及防腐蚀烟囱结构形式和选材进行分析，并根据应用实践对烟囱重要部位防腐构造作了重点探讨。     

铜相纯度对钨铜复合材料性能的影响

钨铜复合材料作为一种用途广泛的粉末冶金材料受到了普遍关注。钨铜复合材料具有良好的耐电弧浸、抗熔焊性和高强度、高硬度等优点,目前被广泛地用作电触头材料、电极材料、电热合金、喉衬材料等。本文分析了铜相纯度对钨铜复合材料电阻率、硬度的影响,并对如何改善钨铜复合材料的微观组织等问题进行讨论。实验研究表明:随着铜相纯度的提高,材料的硬度降低、电阻率减小。     

氧化物杂质对铁氧化物还原动力学的影响

系统分析了氧化物杂质对铁氧化物还原动力学的影响及其机理。发现：各种杂 特点与杂质浓度、存在开矿和／或加入方法,样品的初始化学组成和物理性状,还原剂的种类、反应温度、还原分数等多种因素有关。     

水热温度对水合氧化铝相结构及微观形貌的影响

采用铝醇盐水热处理方法制备薄水铝石(Al2O3.xH2O)。研究了在100~180℃范围内水热处理温度对产物性能影响。XRD结果表明随水热处理温度升高,水合氧化铝由拟薄水铝石转变为结晶良好的薄水铝石,微观形貌从无规线团结构转变为菱形片层结构。由不同处理温度获得的TG曲线可计算出获得产物中含水量x在1.06~1.67。水热处理获得的薄水铝石经600℃焙烧获得γ-Al2O3,但其微观形貌不发生改变。     

热等静压(HIP)对CVDZnS光学性能的影响

对化学气相沉积(CVD)ZnS经热等静压(HIP)处理前后在光学透过率等方面的改变进行了比较分析。针对温度、原生样品厚度等因素对样品性能的影响做了详细阐述。实验表明，热等静压对原生CVDZnS光学性能有促进作用，随处理温度的升高，透过率在1010～1050℃之间出现峰值；原生样品厚度的影响不容忽视，导热均匀的薄样品晶粒均匀且尺寸较大，光学及力学性能要好于厚样品。     

Cu含量对Al-Cu合金板材组织及性能的影响

本文通过先熔炼铸锭,后轧制成板材的方法,制备了不同Cu含量的铝铜合金板材,研究了Cu含量变化(1.287%～9.806%)对合金板材显微组织、力学性能和成形性能的影响。结果表明,随着Cu含量的增加,合金中弥散析出的第二相质点逐渐增多;Cu含量在5.654%～9.806%范围时合金的力学性能较为理想,当Cu含量为5.654%时,合金的成形性能最好,此时板材的极限拉伸系数为0.75,制耳率低至3.8%。     

聚乙二醇对锂电铜箔组织性能的影响

利用直流电沉积技术在纯钛阴极上制备电解铜箔,在含有光亮剂和整平剂的电解液中加入0~6 mg/L聚乙二醇（PEG）,对电解铜箔表面状态和力学性能均产生影响。随着PEG浓度增加,铜箔抗拉强度轻微增加;过量的PEG则导致铜箔表面粗糙度增大。通过扫描电子显微镜（SEM）观察铜箔表面形貌发现：加入0~4 mg/L PEG可制得表面较为平整的电解铜箔,过量的PEG会使得铜箔表面出现球状突起。     

铜炉渣的可磨性及综合回收性能的影响因素分析研究

本文论述了铜冶炼炉渣浮选回收铜的影响因素,并指出熔融炉渣冷却方式及冷却速度是影响铜冶炼炉渣浮选回收铜的主要因素。对白银有色集团公司铜冶炼厂的两种铜炉渣的可磨性及综合回收性能进行了对比,并分析了难以获得铁精矿的原因和含铁硅酸盐的形成过程,再次证明了熔融炉渣的冷却方式及冷却速度是影响炉渣浮选回收铜的主要因素。     

添加铜对ZA12合金摩擦磨损性能的影响

研究铜对ＺＡ１２合金组织结构的作用,探讨铜对合金摩擦磨损性能的影响。随着铜添加量的变化,摩擦磨损性能有显著的改变。     

Structural Analysis and Magnetic Properties of Gd-Doped Li-Ni Ferrites Prepared Using Rheological Phase Reaction Method

A series of Gd-doped Li-Ni ferrites with the formula of LiNi0.5GdxFe2-xO4 where x = 0.00 - 0.08 in steps of 0.02, were prepared by thermolysis of oxalate precursors obtained by rheological phase reaction. The structure, morphology, and the magnetic properties of the samples were characterized by powder X-ray diffraction （XRD）, atomic force microscopy （AFM） and a vibrating sample magnetometer （VSM）. A single spinel phase was obtained in the range of x = 0.00 - 0.04. The lattice parameters of the Gd-doped samples were larger than that of pure Li-Ni ferrite, and increased in the range of 0.00 ≤ x ≤ 0.04, then decreased up to x = 0.08, because of the formation of the secondary phase （Gd- FeO3）. All samples were spheric particles with an average size of about 100 nm, but agglomerated to some extent. The hysteresis loops indicated that the saturation magnetization decreased gradually with increasing Gd content, while the variation of coercivity was related to the microstructure of the Gd-doped samples.     

含锰结构钢中带状组织及其对力学性能的影响

对含锰结构钢中带状组织的形成演化规律及对冷轧板力学性能的影响进行了研究。结果表明,钢板中的带状组织是由连铸过程中元素的中心枝晶偏析所致。带状组织的存在对冷轧板的强度无明显影响,但使冷轧板的塑性显著降低,从而影响产品的使用性能。采取控制连铸时钢水的过热度、加大电磁搅拌等措施,可减轻铸坯的中心偏析,遏制带状组织的形成。     

玻璃粉粘结剂对丝网印刷Zr-V-Fe吸气剂薄膜吸气性能的影响

利用丝网印刷技术制备Zr-V—Fe吸气剂薄膜。以Pb玻璃粉作为薄膜与基片的粘结剂，研究了三种不同退火温度下制备的Zr—V—Fe吸气剂薄膜的吸气性能，通过XRD，FESEM，EDS及吸气性能测试，分析讨论了薄膜的相组成、表面形貌和表面成分对吸气性能的影响。结果表明，退火温度变化会使薄膜表面Pb含量发生改变，从而引起吸气剂薄膜的吸气性能发生变化，在玻璃粉的熔点温度（350℃）进行退火，所得的薄膜具有更多清洁有效的表面，此时玻璃粉对薄膜的吸气性能影响最小，薄膜的吸气性能最佳。     

La0.8Ca0.2CrO3体系复合氧化物的甘氨酸-硝酸盐法合成与导电性能

采用甘氨酸-硝酸盐法合成La0.8Ca0.2CrO3复合氧化物粉料,对合成产物的晶体结构和显微形貌进行表征,研究烧成温度对La0.8Ca0.2CrO3相对密度和电导率的影响.实验结果表明,烧成温度为1400℃时样品即达较高的相对密度(92.6%),测试温度为800℃时样品的电导率为31.1 S·cm-1.与常规固相法相比,GNP法合成产物的纯度高、颗粒细(100nm～200nm),有良好的烧结活性,能够有效地降低材料的烧成温度和提高材料的电性能.     

快速凝固AlSi17Fe6Cu4.5Mg0.5合金的组织及性能

采用超音速气体雾化法制备快速凝固高硅铝合金粉末，通过热挤压法对雾化合金粉末进行固结成形，并利用T6处理工艺对挤压态合金进行热处理。对不同状态合金材料的组织及变化特征进行研究，同时对挤压态及T6处理态合金拉伸性能和耐磨性进行测试。     

The Effect of Alkali Concentration on the Structural and Magnetic Properties of Mn-Ferrite Nanoparticles Prepared via the Coprecipitation Method

MnFe₂O₄ nanoparticles were synthesized using the coprecipitation method under two different NaOH concentration settings as reaction agents at 355 K (82 °C). Structural and morphological properties of the nanoparticles were examined using X-ray diffraction and a scanning electron microscope. The decrease of NaOH concentration led to the increase of particle size. This result contradicts two recently published reports. Also, the decrease of NaOH concentration led to more crystallinity and a narrower particle size distribution. The results were evaluated from a chemical point of view and were based on the supersaturation level, which was influenced by alkali concentration. It was concluded that the higher NaOH concentration led to a more rapid nucleation and more random cation distribution. The magnetic properties of the nanoparticles examined by permeameter and faraday-balance equipment were consistent with the structural and morphological properties of the particles.     

The Influence of Heat Treatment on Structural and Mechanical Properties of the Tool Steel

Metallurgist - The present research work aims to study the heat treatment effect on the structural and mechanical properties of the tool steel AISI D2. The steel has undergone a double treatment....     

Tribological and Mechanical Properties of Al(Cu)/MWCNT Nanocomposite Prepared by Mechanical Alloying and Hot Extrusion

The bulk Al–Cu-multiwall carbon nanotube (MWCNT) nanocomposite was prepared using mechanical alloying (MA) and hot extrusion processes. Al–4 wt % Cu powder mixture was first milled for 20 h to form the nanostructured Al(Cu) solid solution. The MWCNT was then added to the Al(Cu) powder mixture and further milled for 5 h. X-Ray Diffraction (XRD) and Differential Thermal Analysis (DTA) were performed to study the phase transformations during mechanical alloying and hot extrusion. Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) were also employed to study the samples microstructure. Mechanical properties of the bulk Al(Cu)/CNT nanocomposite were also studied using room and high temperature compression and wear tests. The results showed that after 20 h of mechanical alloying, a supersaturated Al(Cu) solid solution with the average grain size of 25 nm was achieved. Homogenous distribution of CNTs in the Al(Cu) supersaturated matrix was obtained. CNTs retained their tubular structure after 5 h milling time. Hot extrusion process at 550°C also led to the formation of bulk samples with nearly full density. The average yield and compressive strength of the Al(Cu)/CNT nanocomposite were found to be around 450 and 590 MPa at room temperature. The bulk nanocomposite showed suitable thermal stability by keeping its strength up to 300°C.     

Influence of Carbon on Mechanical Properties of Cu bearing Extra Low Carbon Steel Sheets

This paper examines the effect of carbon (C) on solid solution strengthening, bake hardening and anti‐strain aging property for copper (Cu) bearing extra low carbon (ELC) steel sheets. For this purpose, five ELC steels that contain different content of C were selected. We have investigated the effect of C on mechanical properties and microstructures for the continuous annealed ELC steel sheets. Mechanical properties and microstructures were analyzed as well using uni‐axial tensile test and electron back‐scattered diffraction (EBSD) technique following pilot rolling and continuous annealing. It has been found that the addition of C increases the solid solution strengthening as well as 19.9MPa per 0.0010wt%C in yield strength. What is more, the addition of C increases the bake hardenability (BH) as well as 18.7MPa per 0.0010wt%C. In addition, the addition of C delays the recrystallization during continuous annealing process. From an industrial standpoint, it is possible to control both a stable anti‐strain aging property and high bake hardenability for the ELC steel sheets without Ti and Nb addition.