Zhiyun Han
材料科学技术（英）
In this paper, Me (Me=Cr, Zr) and N co-doped diamond like carbon (DLC-MeN) composite films were prepared on cemented carbide substrates by pulsed bias arc ion plating. The effect of nitrogen flow rates on the microstructure and properties of the films were investigated by X-ray photoelectron spectroscopy (XPS), Raman spectra, grazing incident X-ray diffraction (GIXRD), high resolution transmission electron microscopy (HRTEM) and nano-indentation. Raman, GIXRD and HRTEM results show that the deposited films are nanocomposite films with MeN nanocrystalline phase embedded within DLC amorphous matrix, which are vital for the mechanical properties of the films. The nitrogen flow rate has significant effect on the compositions and structures and hence on the hardness and elastic modulus of the films, and increasing nitrogen flow rate decreases drastically the hardness and elastic modulus of the films.
关键词:
Diamond like carbon films
,
doping
,
Nitrogen flow rate
,
Arc ion plating
杨晨璟
,
杜景红
,
甘国友
,
严继康
,
易健宏
材料科学与工艺
为了精确控制共沉淀包膜法制备掺杂TiO2粉体的反应条件,本文通过对Men＋（Ni2＋、La3＋、Fe3＋、Al3＋）在NaHCO3-NH3.H2O体系中离子沉淀反应平衡的热力学分析,得到了Men＋-CO32--NH3.H2O体系中不同总氨浓度cN和总碳浓度cC时各金属离子总浓度与pH值的关系图,并由此确定了金属离子完全沉淀的最佳pH值.热力学分析表明,以NaHCO3-NH3.H2O作为沉淀剂,采用共沉淀包膜法制备掺杂TiO2粉体时,当cN=0.010 mol/L和cC=1.000 mol/L时,反应的适宜沉淀pH为9.0左右.
关键词:
热力学分析
,
共沉淀包膜
,
掺杂
,
TiO2
高从堦
,
蔡邦肖
,
陈欢林
,
钱锦文
膜科学与技术
doi:10.3969/j.issn.1007-8924.2003.04.001
用不同的方法制备了几种分离有机物的膜,如CA/PAN、PVA/PAN的复合膜,以及含金属离子载体的PVA膜,这些膜是复合膜或非对称膜.测量了膜材料(CA和PVA-Men+)的吸附特性并评价了其性能.结果表明,CA和CTA膜以及几种复合膜适于分离MTBE/MeOH,修正的溶解-扩散模型可成功地估算MTBE/MeOH透过CA膜的渗透汽化分离性能.从初步吸附试验看,含金属离子载体的PVA 膜对分离苯/环乙烷体系可能是一好的候选膜.
关键词:
渗透汽化
,
膜
,
有机物分离
彭忠东
,
杨建红
,
邹忠
,
刘业翔
,
李自强
无机材料学报
doi:10.3321/j.issn:1000-324X.1999.05.005
本文通过对Men+(Zn2+, Cr3+, Mn2+, Sb3+, Bi3+, Co2+)-NH3-CO2-3-H2O体系进行热力学分析的基础上, 获得了Me-NH3-CO2-3-H2O 体系中的lg[M]T-pH关系图,得到了用NH4HCO3和NH32O作沉淀剂,用共沉淀法制备掺杂氧化锌压敏陶瓷粉料时,最佳共沉淀pH为7.0左右.
关键词:
热力学分析
,
共沉淀
,
氧化锌
,
压敏陶瓷
ZHENG Wenlong ZHU Xiying SU Limin Shanghai Research Institute of Materials
,
Shanghai
,
China ZHENG Wenlong
,
Senior Research Engineer
,
Shanghai Research Institute of Materials
,
99 Handan Road
,
Shanghai
,
China
金属学报(英文版)
Fracture behaviour of low-alloy steels AIST4340,HY100,Welten60,AISIA537 and A131 in artificial seawater under static,cyclic loading and at cathodic protection potential has been investigated by using the techniques of fracture mechanics, electrochemistry and electronfractography.The results reveal that at hydrogen evolution potentials(cathodic pro- tection potential)the critical yield strength required for the occurrance of SCC decreases from 985 at corrosion potential(E_c)to 872 MPa.The effect of cathodic protection on crack propagation of corrosion fatigue(CF)is not simple,it is closely related to the yield strength of steels and their SCC behaviour.For the steels with high yield strength,cathodic protection promotes(da/dN)_Ⅱ evidently,and reduces △K_(th) value.The(da/dN)-△K curves dis- play a plateau at the third stage of CF for steels with medium or low yield strength.It is men- tioned that the cathodic protection potential for oceaneering constructures should be control- led at top level of the protective range.It seems reasonable that the strength of steel for oceaneeing use might be increased by 200 or 300 MPa.
关键词:
low-alloy steel
,
null
,
null
,
null
,
null
W. Chen
,
D. Fergson and H. Ferguson (Dynamic Systems Inc. Poestenkill
,
NY 12140
,
USA)
金属学报(英文版)
There is a considerable interest in developing methods for processing of materials with ultrafine grain si- zes. Widely used methods in refining microstructure are severe/intense plastic deformation techniques, such as torsion straining, equal channel angular (ECA) pressing/extrusion,and accumulative roll bonding (ARB) technique.While the torsion technique has been available for decades,a new torsion system has been developed at DSI for simulation of complex stress states such as combination of shear and compression or shear and tension stress states. The equal channel angular pressing technique is ma- inly used for production of ultrafine grain aluminum alloys,which is aimed at develoment of high strain rate superplasticity.The accumulative roll bonding technique has been applied for the rolling of both aluminum alloy and steels to produce ultrafine gained materials. Three different types of hot compression deformation methods, each with a different number of deforma- tion axis, are introduced in this paper. They are single axis deformation, two axis deformation and three axis deformation.The single axis deformation has us or little restraint such as plane strain type testing and axisymmetric compression testing, the two - axis deformation can be fully restrained or un- restrained, and the three - axis deformation has no restraint. The two - axis restrainsd compression deformation techopue is recommended for loboratory side after comparing the single - axis and the three - axis deformation techniques since the bulk volume of the two - axis restraint compression speci- men can be easily machined into mechanical testing speciments for mechanical property measurement and other studies,and the technique can be aplied to studies of any metallic materials.
关键词:
ultrafine grain
,
null
