新型系列准贝氏体钢

介绍了我们多年的研究成果－－新型系列准贝氏体钢，该系列钢具有独特的组织和性能，以及广阔的应用前景。     

水量对锐钛矿溶胶制备、结构及光催化性能的影响

选择“钛酸丁酯-水-乙醇-盐酸”的溶胶．凝胶反应体系，考察反应物水的用量变化对反应过程、溶胶结构和光催化性能的影响，并获得了含有锐钛矿晶体、具有光催化性能的氧化钛溶胶。钛酸丁酯与水的摩尔比为1：2、1：4、1：8时，会逐渐形成凝胶，溶胶常温干燥后的粉体呈无定型结构，透射电镜中只能观察到细小的成膜粒子，溶胶不能使罗丹明B溶液分解褪色。钛酸丁酯与水的摩尔比为1：40、1：100、1：200时，钛酸丁酯发生充分水解，有可能形成稳定的溶胶；溶胶常温干燥后的粉体呈锐钛矿晶型，且结晶强度随水的用量的增加而增强；透射电镜中可观察到松散的团聚体、初显正方形较为紧密的结晶体和致密规则的正方形锐钛矿晶体；各溶胶均可催化降解罗丹明B使其褪色。     

Ti-26高强钛合金斜轧穿孔工艺研究

研究了Ti-26高强钛合金斜轧穿孔制备管坯工艺。测试了穿制的Ti-26合金管坯的力学性能，用金相显微镜观察了管坯的显微组织，用扫描电镜分析了拉伸断口的形貌。结果表明，采用斜轧穿孔方式完全可以制备Ti-26高强钛合金管坯；在1050℃下，选择合适的轧辊转速和前进角可顺利穿制Ti-26高强钛合金管坯，其管坯的强度为815MPa，延伸率达到13％，断面收缩率达到45％，晶粒度按ASTME标准为6级，比穿孔前细化，断口呈明显的塑性断口，加工管材无需热处理可以直接进行轧制，道次加工率可达45．8％。     

Mn,Zr对Mg-Gd-Y合金组织与力学性能的影响

研究了微量Mn、Zr对Mg-13%Gd和Mg-9%Gd-4%Y合金铸态和挤压后的微观组织及力学性能的影响.结果表明:在铸态,含Zr合金的晶粒明显小于不含Zr的合金,而Mn对合金的铸态显微组织影响不大;将Mg-9%Gd-4%Y-0.6%Mn和Mg-9%Gd-4%Y-0.6%Zr合金挤压后,都可以得到非常细小均匀的等轴晶,晶粒尺寸约14 μm;这两个合金在挤压时效态(T5)的力学性能都明显优于WE54合金的,且Mg-9%Gd-4%Y-0.6%Zr合金比Mg-9%Gd-4%Y-0.6%Mn合金性能更好.     

Accu Roll轧管机的背景、现状及前景

对Accu Roll轧管机的产生背景进行了回顾,对目前国内Accu Roll轧管机的使用现状进行了分析,在肯定其优点的同时,指出了该类轧管机存在的共同问题,提出了完善轧管机性能的可能途径及选择轧管机应注意的问题。     

TEMPERATURE DEPENDENCE ON HARDNESS AND EXPANSION OF SINTERED Nd-Fe-B MAGNETS

<正> Nd-Fe-B 合金,除用粉末冶金方法制备外,也用快淬、热压工艺制成具有优异性能的各向异性永磁体.实验表明,快淬 Nd-Fe-B合金的热压致密体于700℃下模压,若断面收缩达50%,则 Nd_2Fe_(14)B 基相的微晶因其 C 轴平行于压制方向而具有强的择优取向.显然,高温模压是用快淬合金制备高性能磁体的关键工艺,应变诱导晶粒长大和晶粒取向均在高温模压过程中完成.为探索快淬、热压磁体各向异性的成因,进而确定最佳热压工艺,有必要研究合金机械性     

国防生模拟连排建制管理的教育功能

依托普通高校培养军队干部是新时期我国国防建设的重大举措。本文针对普通高校如何完成该培养任务 ,在总结了中南大学国防生培养管理工作实践经验的基础上 ,提出了国防生模拟连排建制的管理模式 ,并对它的功能进行了具体分析。     

In situ technique for synthesizing multiple ceramic particulates reinforced titanium matrix composites (TiB + TiC + Y2O3)/Ti

In situ synthesized titanium matrix composites reinforced with multiple ceramic particulates including TiB, TiC and Y₂O₃ were fabricated by non-consumable arc-melting technique utilizing the chemical reaction among Ti, B₂O₃, B₄C and Y. The thermodynamic feasibility of the in situ reactions has been considered. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composites were observed by means of optical microscope (OM), scanning electron microscope (SEM) and electron probe. It is concluded that multiple reinforcements are synthesized and they show different shapes: TiB grows in needle shape; TiC grows in near-equiaxed and rod-like shapes; Y₂O₃ grows in near-equiaxed shapes when the content of Y is 0.6 wt.% and grows in dendritic shapes when the content of Y increases to 1.8 wt.%. Reinforcements TiB, TiC and Y₂O₃ are distributed uniformly in the titanium matrix.     

NANO-MULTILAYERS WITH HIGH PERPENDICULAR ANISOTROPY FOR MAGNETIC RECORDING

(FePt/Ag)n nano-multilayers were deposited on MgO (100) single crystal with laser ablation and then subjected to annealing. FePt L1o grains with (001) texture and thus a large perpendicular magnetic anisotropy constant Ku of the order of 106 J/m3 were formed. A thick Ag layer is found to be favorable for decreasing the dispersion of the easy axis for magnetization. The measurement of time decay of magnetization gave rise to a small activation volume of the order of 10-25m3, showing the promising of being the recording medium for future high density perpendicular recording.     

MICROSTRUCTURE AND PROPERTIES OF C-Cu NANOSTRUCTURE THIN FILM

Nanostructured C-Cu thin films were deposited by reactive sputtering method and co-sputtering method. The relationships between microstructures, properties, and depo-sition parameters were studied and the results obtained from TEM, AFM, and XPS.indicate that the thin films are nanostructural, and have good in-depth uniformity. Theselected area electron diffraction (SAED) found that the nanosize Cu particles havethe fcc structure and the others are amorphous carbon or nanocrystallized graphiticcarbon. The peak positions of the Cu and C in XPS indicate them to be at the ele-mental state. In the IR transmission spectrum, diamond two-phonon absorption andgraphite Raman peaks were observed, which suggests microcrystal diamond particlesand graphite components exist in the C-Cu film. The higher electrical resistivity wasobtained.