M.B.Peterson(Wear Sciences Corporation
,
Arnold
,
Maryland
,
USA)Shizhuo LI(Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)S.F.Murray(Rensselaer Polytechnic Institute
,
Thoy
,
New York
,
USA)
材料科学技术（英文）
A study was conducted to develop low-friction, wear-resistant surfaces on high temperature alloys for the temperature range from 26℃ to 900℃. The approach investigated consists of modifying the naturally occurring oxide film in order to improve its tribological properties. Improvement is needed at low temperatures where the oxide film, previously formed at high temperature, spalls due to stresses induced by sliding. Experiments with Ti, W and Ta additions show a beneficial effect when added to Ni and Ni-base alloys. Low friction can be maintained down to 100℃ from 900℃. For unalloyed Ni friction and surface damage increases at 400℃ to 500℃. Two new alloys were perpared based on the beneficial results of binary alloys and ZrO2 diffusion in Ni.Low friction at temperature above 500℃ and reasonable values (0.32~0.42) at low temperature are obtained.
关键词:
P.Sit
金属学报(英文版)
Friction and sliding wear behaviour of Ti-B-N coatings against AISI440C steel ball and WC-6wto ball were studied by using pin-on-disk tribometer along with microstructure characterization using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). It is shown that the wear resistance of film depended on the wear mechanism. In the case of AISI440C steel, adhesive wear were pre-dominant and the wear rate increased sharply to a maximum when N content reach -38at. This might be related to the change of film microstructure and phase configuration, so the least adhesive transfer of tribo-film was observed. If WC-6wt0o ball was used, less deformation wear debris was observed, this was responsible for the rise of wear rate. Despite of different wear modes, friction coefficients in both cases were found to depend mainly on the formation and the amount of h-BN phase. Elemental anal)sis by energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) revealed that oxygen participated in the wear behavior by reacting with films to form the debris comprised of various types of Ti oxide including TiO, TiO2 and Ti2O3, which increased wear resistance.
关键词:
dry sliding wear
,
null
,
null
ZHANG Shourong
钢铁研究学报(英文版)
One of the problems encountered in 60′s to 80′s of 20th century in China′s steel industry was short life of blast furnace shaft as well as the excessive erosion of blast furnace hearth. A series of research work was carried out in order to extend blast furnace campaign life. The concept of research and development was integrated in the construction of BF (blast furnace) No5 at WISCO (Wuhan Iron and Steel Corporation), and in October, 1991, the BF No5 was blown in. The blast furnace has worked smoothly for more than 15 years without any medium repair even guniting. It is expected that the campaign life of BF No5 would be longer than 16 years with a production over 11 000 t per unit inner volume (m3). A new blast furnace with an inner volume of 3 400 m3 is under construction, and is designed with a campaign life of 20 years without any medium repair. The campaign life of blast furnaces in China has been extended in recent years.
关键词:
blast furnace;campaign life;erosion
Wear
The non-lubricated, sliding friction and wear behavior of Ti3Si(Al)C-2 and SiC-reinforced Ti3Si(Al)C-2 composites against AISI 52100 bearing steel ball were investigated using a ball-on-flat, reciprocating tribometer at room temperature. The contact load was varied from 5 to 20 N. For monolithic Ti3Si(AI)C,, high friction coefficients between 0.61 and 0.90 and wear rates between 1.79 x 10(-3) and 2.68 x 10(-3) mm(3) (N m)(-1) were measured. With increasing SiC content in the composites, both the friction coefficients and the wear rates were significantly decreased. The friction coefficients reduced to a value between 0.38 and 0.50, and the wear rates to between 2.64 x 10(-4) and 1.93 x 10(-5) mm(3) (N m)(-1) when the SiC content ranged from 10 to 30 vol.%. The enhanced wear resistance of Ti3Si(Al)C-2 is mainly attributed to the facts that the hard SiC particles inhibit the plastic deformation and fracture of the soft matrix, the oxide debris lubricate the counterpair, and the wear mode converts from adhesive wear to abrasive wear during dry sliding. (c) 2006 Elsevier B.V. All rights reserved.
关键词:
Ti3Si(Al)C-2-based composites;SiC;friction;wear resistance;mechanism;self-lubrication mechanism;ti3sic2-based material;grain-size;ceramics;transition;coatings;abrasion;hardness;couples
Journal of the Less-Common Metals
High-field magnetization measurements were performed on magnetically aligned samples of quasi-ternary compounds of the Pr2(Fe,M)14B series with M = Al, Ga and Si at 4.2 K in magnetic fields up to 35 T. The saturation magnetization and anisotropy constants were derived as functions of composition. The results suggest that the transition in the magnetization curves of these series is probably not a first-order magnetization process (FOMP).
关键词:
crystal;anisotropy;pr2fe14b
Mehdi Mazar Atabaki
,
Sajjad Jafari
,
Hassan Abdollah-pour
钢铁研究学报(英文版)
Abstract： Wear properties of two different crushers used for grinding raw materials of cement industry are compared using pin-on-disk wear test. The wear test was carried out with different loads on a pin. Abrasive wear behavior of two alloys was evaluated by comparing mass loss, wear resistance, microhardness and friction coefficient. The microstructure of the specimens was detected using optical microscope. The results showed that abrasive wear of high chromium cast iron is lower than that of Hadfield steel. Due to the presence of M7C3 carbides on the high chromium cast iron matrix, impact crushers exhibited higher friction coefficient.
关键词:
Key words: abrasive wear
,
Hadfield steel
,
high chromium
,
cast iron
Journal of Applied Physics
The magnetic properties of nanocomposite multilayer magnets of the (Nd,Dy)(Fe,Co,Nb,B)(5.5)/M (M=Co,FeCo) on Ti-buffered Si substrates have been investigated. X-ray diffraction results reveal that the Nd2Fe14B-type phase in almost all the films is randomly oriented. Different thickness x (nm) for Co layers and y (nm) for FeCo layers were adopted in the multilayers. It is found that high remanence is achieved in the nanocomposite multilayer films consisting of the Nd2Fe14B-type phase and soft magnetic phase for Co with 6greater than or equal toxgreater than or equal to4 and for FeCo with 10greater than or equal toygreater than or equal to6. The enhancement of the remanence in the nanocomposite multilayer films is attributed to the exchange coupling between the magnetically soft and hard phases. Increasing the soft magnetic components results in a continuously decreasing coercivity. (C) 2002 American Institute of Physics.
关键词:
remanence enhancement;fe;films
Wear
The effect of additives on the tribological behaviour of 1045 steel in NaCl and H2SO4 solution was investigated. Four substances (K2Cr2O7, sodium dodecyl benzene sulphonate (SDBS), (CH2)6N4 and IMC-5) were used in both solutions as additives to control the corrosive wear loss of specimen. A pin-on-ring wear apparatus and a rotating scratching device with a speed regulator were designed and manufactured for the investigation of steady and transient corrosive wear process. The dependences of friction coefficient and wear loss of specimen vs. load and speed in both aggressive media with or without additives were determined and the morphology of wear tracks was observed by scanning electron microscopy. In order to explain the effect of additives on corrosive wear, the re-formation rate of the passive film and the effect of additives on polarization curves were also determined for the same testing condition. The results show that the roles of additives in corrosive wear can be divided into three types in reducing material removal: (a) as the lubricating additive in a heavy duty and mild corrosive medium (SDBS); (b) as the corrosive inhibitor in a low duty and severe aggressive medium (K2Cr2O7 and (CH2)6N4); (c) as the corrosive wear inhibitor in serious situations (IMC-5).
关键词:
Journal of Magnetism and Magnetic Materials
Phase constitution and magnetic properties of Nd10Fe76B4M10 and Nd10Fe76B2M12 (M = Fe,Ti,V,Cr, Mn,Co and Al) alloys prepared by mechanical alloying and subsequent annealing have been systematically studied. It is found that the components of phases in the alloys critically depend on the additive transition metals M. In all the alloys, only the addition of Ti give significant enhancement to the permanent-magnetic properties. The increase of the Curie temperature in the Ti-doped alloys with an excessively low B content implies that part of the Ti atoms may occupy crystalline sites other than the Fe sites. In all the M additive alloys, with increasing content of the additive elements, the quantity of 1:7 phase increases and that of Nd2Fe14B-type phase decreases, (C) 2000 Elsevier Science B.V. All rights reserved.
关键词:
phase constitution;structure;magnetic properties;alloys;mechanical;alloying;nd;coercivity
