Iron mediated cathodic electrosynthesis of hausmannite nanoparticles

A novel synthetic route has been proposed to prepare hausmannite nanoparticles. The synthetic route comprises an iron mediated constant current cathodic electrodeposition of manganite and heat treatment of the latter to obtain hausmannite. The obtained nanostructures have been characterized using X-ray Diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX) and Fourier transform Infrared Spectrometry (FTIR). The role of iron in the formation of manganite precursor has been studied by cyclic voltammetry (CV) and differential thermal analysis (DTA). A formation mechanism based on iron mediated formation of Mn³⁺ and subsequent cathodic reduction of the disproportionated products has been proposed accordingly. The prepared nanoparticles exhibited specific capacitance of 143 F g⁻¹ in 0.5 M Na₂SO₄ solution. The retained specific capacity was 87% after 2000 cycles.     

Role of Co in formation of Ni-Ti clusters in maraging stainless steel

The effect of Co addition on the formation of Ni-Ti clusters in maraging stainless steel was studied by three dimensional atom probe (3DAP) and first-principles calculation. The cluster analysis based on the maximum separation approach showed an increase in size but a decrease in density of Ni-Ti clusters with increasing the Co content. The first-principles calculation indicated weaker Co-Ni (Co-Ti) interactions than Co-Ti (Fe-Ti) interactions, which should be the essential reason for the change of distribution characteristics of Ni-Ti clusters in bcc Fe caused by Co addition.     

0.88C-1.2Si-0.75Mn-2Al高强度电缆铠装钢用盘条的试制

采用中高碳成分添加低密度元素Si、Al进行轻量化的设计思路设计了试验钢的化学成分,试验钢采用50 kg真空感应炉冶炼。利用金相显微镜、SEM扫描电镜和力学性能检测设备对试制后的Φ6 mm盘条进行了显微组织观察、珠光体片层间距的测量和屈服强度、抗拉强度、延伸率的检验。结果表明:盘条在600℃等温2 h后的金相显微组织为铁素体+珠光体的混合组织,珠光体的片层间距为(126±5) nm,屈服强度大于1 183 MPa、抗拉强度大于1 425 MPa、延伸率大于10%,其力学性能满足电缆用铠装钢的技术要求。     

Modified Mechanical Coating Technique for the Preparation of Nanohydroxyapatite Coated Ti–6Al–4V Dental Implants

Protection of Metals and Physical Chemistry of Surfaces - To improve the mechanical and biological properties and also to increase the lifetime and performance of Ti–6Al–4V dental...     

攀西钒钛磁铁矿尾矿制备储水泡沫陶瓷的研究

以攀西钒钛磁铁尾矿和废玻璃为主要原料通过高温烧结法制备储水泡沫陶瓷，研究原料配比和发泡剂（SiC）添加量对材料性能的影响。结果表明:随着钒钛磁铁矿尾矿含量的增加，材料的体积密度及抗压强度逐渐增大，平均气孔孔径逐渐减小；当尾矿添加量为50 wt%，材料的体积吸水率出现极值。当SiC添加量为0.3 wt%，材料内部气孔分布均匀，平均孔径约为2.93 mm。最终以50.0 wt%的钒钛磁铁矿尾矿和50.0 wt%的废玻璃为原料，外加3.0 wt%的石英，0.3 wt%的SiC，3.0 wt%的Na3PO4，在1040℃下制得性能最优的储水泡沫陶瓷，材料的体积密度为0.26 g/cm-3、体积吸水率为56.5%和抗压强度为0.68 MPa。采用SEM、XRD等检测手段研究材料的微观形貌及物相组成，结果表明储水泡沫陶瓷内部由三维立体结构组成，有利于储存水分；材料主要物相包括硅灰石、长石、透辉石和钛铁矿。      

Facile route to fabricate large-scale silver microtubes

Large-scale uniform Ag microtubes with high length diameter ratios have been first successfully synthesized by a facile approach, using low-cost super fine glass fibers as templates. The samples were characterized by SEM and XRD. The investigations showed that calcining or adding of PEG-1000 and alcohol could greatly improve the mechanical strength of the sample. Especially the products exhibited favorable catalytic properties during the degradation of Rhodamine B by NaBH₄.     

Structural and Superconducting Property Variations with Nominal Mg Non‐Stoichiometry in MgxB2 and Its Enhancement of Upper Critical Field

By applying a combination of characterisation tools, changes in structural and superconducting properties with nominal Mg non‐stoichiometry in Mg_xB₂ are found. The non‐stoichiometry produces enhanced in‐field critical current densities (J_c's) and upper critical field / irreversibility field (H_c2/H_irr(T)) values. Upper critical fields of ～ 21 T (4.2 K) were obtained in nominal Mg‐deficient samples compared to ～ 17 T (4.2 K) for near‐stoichiometric samples.     

注射成形粘结NdFeB磁体:工艺·性能·应用

综合介绍了几种适于注射成形粘结NdFeB磁体的磁粉制备方法及特点；讨论了粘结剂、改性剂及磁场取向对注射成形NdFeB磁体最终磁性能的影响及其应用市场。在此基础上，指出了今后开展研究工作的方向。