Retraction Note to: Ablation Behavior of SiC/ZrB2 Multilayer Coating Prepared by Plasma Spray Method

Metallurgical and Materials Transactions A -     

Microstructures and Mechanical Properties of a New Low Carbon Bainitic Weathering Steel

A low carbon bainitic weathering steel with Cu-P alloying was developed.The mechanical properties and hot-rolled microstructures of the new steel at different finishing temperatures were investigated.Cu-P alloying produced strong solution strengthening,delayed the transformation of austenite to bainite,thereby increased the amount of M/A islands.The interaction of phosphorous and copper atoms with dislocations inhibited the recovery process and the formation of subgrains.Low temperature rolling promoted the formation of bainite plates and reduced the size of M/A island,which were beneficial to improving the low temperature impact toughness of phosphorus-bearing low carbon bainitic steel.     

Silico-ferrite of Calcium and Aluminum (SFCA) Iron Ore Sinter Bonding Phases: New Insights into Their Formation During Heating and Cooling

The formation of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter phases during heating and cooling of synthetic iron ore sinter mixtures in the range 298?K to 1623?K (25?°C to 1350?°C) and at oxygen partial pressure of 5?×?10^?3 atm has been characterized using in situ synchrotron X-ray diffraction. SFCA and SFCA-I are the key bonding phases in iron ore sinter, and an improved understanding of their formation mechanisms may lead to improved efficiency of industrial sintering processes.?During heating, SFCA-I formation at 1327?K to 1392?K (1054?°C to 1119?°C) (depending on composition) was associated with the reaction of Fe₂O₃, 2CaO·Fe₂O₃, and SiO₂. SFCA formation (1380?K to 1437?K [1107?°C to 1164?°C]) was associated with?the reaction of CaO·Fe₂O₃, SiO₂, and a phase with average composition 49.60, 9.09, 0.14, 7.93, and 32.15?wt pct Fe, Ca, Si, Al, and O, respectively. Increasing Al₂O₃ concentration in the starting sinter mixture increased the temperature range over which SFCA-I was stable before the formation of SFCA, and it stabilized SFCA to a higher temperature before it melted to form a Fe₃O₄?+?melt phase assemblage (1486?K to 1581?K [1213?°C to 1308?°C]). During cooling, the first phase to crystallize from the melt (1452?K to 1561?K [1179?°C to 1288?°C]) was an Fe-rich phase, similar in composition to SFCA-I, and it had an average composition 58.88, 6.89, 0.82, 3.00, and 31.68?wt pct Fe, Ca, Si, Al, and O, respectively. At lower temperatures (1418?K to 1543?K [1145?°C to 1270?°C]), this phase reacted with melt to form SFCA. Increasing Al₂O₃ increased the temperature at which crystallization of the Fe-rich phase occurred, increased the temperature at which crystallization of SFCA occurred, and suppressed the formation of Fe₂O₃ (1358?K to 1418?K [1085?°C to 1145?°C]) to lower temperatures.     

碳含量对新型Fe-Ni-Mn-Si-C系TWIP钢组织和力学性能的影响

通过光学显微镜、X射线衍射和透射电镜等方法研究了碳含量对Fe-Ni-Mn-Si-C系合金微观组织和力学性能的影响。结果表明:Fe-Ni-Mn-Si-C系合金的主要塑性变形机制为孪生诱发塑性(TWIP)效应。碳的质量分数由0.70%增加至0.98%,合金的屈服强度和抗拉强度分别由391 MPa和860 MPa增大到458 MPa和974 MPa,伸长率由63.6%提高到69.2%。随着碳含量的提高,Fe-Ni-Mn-Si-C系合金出现明显的动态应变时效现象。Fe-15Ni-12Mn-2.5Si-XC合金具有良好的应变硬化能力,随着碳的质量分数提高至0.98%,最大应变硬化指数达到0.73。     

Investigation into the Influence of the Structure Dispersion and Homogeneity on the Properties of Powder Metastable Austenitic Carbide Steels and Diamond Tools

Diffusion and homogenization in “iron (5 μm–nickel (5 μm or 50 nm)” powder systems of various degrees of dispersion during sintering (900 and 1000°C), as well as spark plasma sintering, are investigated using the Matano–Boltzmann method. Calculated diffusivities in pairs of micron powders sintering without applying pressure (900°C, 6 h) and by the spark plasma method (900°C, 5 min) in these systems are equal to 7 × 10–10 cm2/s. It is shown that the use of nanodispersed nickel powder in diffusion pairs based on finely dispersed iron powder promotes a twofold increase in diffusivity at 900°C in contrast to the pair with the microdispersed nickel powder. Constants in the Ivensen sintering kinetics equation are calculated for the “iron–nickel” powder systems, by which the factors activating sintering of these systems are established. The dependences of the structural phase composition and physicomechanical properties of carbide steels of the Fe(base)–14 wt % Ni–8 wt % TiC system on the sintering temperature in range t = 900–1200°C and structure dispersity and homogeneity are determined. The dependences of the grain size, porosity, hardness, microhardness, fracture toughness, and bending ultimate strength on the sintering temperature are shown. Dependences of tribotechnical properties on the degree of homogeneity of the solid solution and volume of the phase transformation of metastable austenite into deformation martensite during abrasive friction turn out similar for carbide steels and diamond tools based on carbide steel. Optimal values of the variation coefficient of the nickel concentration in austenite and carbide steels of the same chemical composition but with different degrees of dispersity, which provide the maximal volume of the austenite decomposition and high values of the diamond-tool grinding coefficient, turn out equal to 5 in both systems, but the sintering parameters are different. It is shown that the physicomechanical properties of the studied systems depend on the structure porosity and dispersity, while tribotechnical properties depend on the structural homogeneity of steels.     

二氧化钛直接电解提取钛短流程绿色新技术

钛金属因其特殊的性能而成为许多领域中的重要材料。虽然钛资源丰富，但由于传统工艺中钛金属生产成本过高而使钛工业的发展受到了限制，综述了目前国内外海绵钛的制造工艺，重点对二氧化钛熔盐电解提取钛新技术进行了论述，其中包括过程原理，实验装置等，并展望了该工艺的前景。     

低C含7.7%Ni低温钢经两相区淬火后的组织性能

 提出了一种Ni质量分数为7.7%的低C低温用CrNi钢,研究了其经淬火+两相区淬火+回火（QLT）处理后的力学性能,采用扫描电镜（SEM）、透射电镜（TEM）、X射线衍射（XRD）和电子背散射衍射（EBSD）对试验钢的显微组织演化规律进行了研究。结果表明：经QLT处理的试验钢的显微组织主要为铁素体（F）+板条马氏体（LM）+马氏体/奥氏体组元（M/A）+回转奥氏体（γ′）。随着两相区热处理温度（tL）的升高,LM的比例逐渐增加,F的比例逐渐减少,晶粒细化,大角度晶界（HAGB）比例和平均晶界角度（AGBA）大幅增加。当tL在650~680℃时,γ′的体积分数约为7%。-196℃下韧性（KV2）主要取决于γ′含量和HAGB比例两个因素。经QLT处理,试验钢的屈服强度（Rp0.2）大于530MPa,抗拉强度（Rm）大于670MPa,-196℃下的冲击韧性大于150J,强韧性达到了当前9Ni钢的水平。     

Friction Hydro-Pillar Processing of a High Carbon Steel: Joint Structure and Properties

Metallurgical and Materials Transactions B - A coupled experimental and theoretical study is reported here on friction hydro-pillar processing of AISI 4140 steel, which is a novel solid-state...     

Improvement in the Environmental Resistance to Oxidation and Surface Properties of Simple Carbon Steel Using Aluminum Coating

In the present work, using a new approach, Fe?CAl intermetallics were formed on the surface of a low-carbon steel (ST52) in order to study its effects on the oxidation, hardness and abrasive behavior. The samples were welded with gas tungsten arc welding technique using an aluminum?Ciron powder (stoichiometry ratio of 1:1) as filer. The microstructural evolutions of coated samples were then characterized using scanning electron microscopy and X-ray diffraction techniques. Besides, hardness and abrasion tests were carried out to study the abrasive behavior of coated layer. The resistance to hot oxidation of coated samples were evaluated by heating to 500, 600 and 700?°C and holding for 2?h. The results show that Fe₃Al and aluminum?Ciron carbide (FeAlC_0.65) were formed on surface of samples. The formation of these phases resulted in increase in the hardness and oxidation resistance, while no improvement on the wear resistance was observed.     

Fabrications of Surface Nanocomposite by Friction Stir Processing to Improve Mechanical and Microstructural Properties of Low Carbon Steel

Friction stir processing was used to fabricate metal matrix composites on the surface of low carbon steel. In this research for making 2 mm surface MMC, the groove method was applied to fabricate TiB₂ nanocomposite via cylindrical tool made of tungsten carbide. Microstructural properties of FSPed samples were studied by optical microscopy and scanning electron microscopy. To evaluate mechanical properties, the micro hardness and tensile properties of MMC were measured. The results indicated that the surface nanocomposite produced by this method had excellent properties. The microstructure of surface MMCs became fine (ferrite grain size became about 1–2 µm) with no defect and porosity. Moreover by adding TiB₂ nanoparticles to the low carbon steel matrix alloy, mechanical properties were improved. Micro hardness can become 200HV higher than that of the base metal. The surface nanocomposite also exhibited better tensile strength when sample yield stress increased to about 28 %.     

The Reaction Behavior of Direct Reduced Iron (DRI) in Steelmaking Slags: Effect of DRI Carbon and Preheating Temperature

An experimental study was conducted to quantify the rate of direct reduced iron (DRI) decarburization in a steelmaking slag using the constant volume pressure increase technique. Experiments were conducted by dropping DRI pellets into molten slag at temperatures from 1773 K to 1873 K (1500 °C to 1600 °C). Subsequent experiments were carried out in which the DRI pellets were preheated while the slag temperature remained constant. The effect of the initial carbon content and the preheating temperature of the DRI on the reaction rate was investigated. The decarburization of DRI seems to comprise two stages, a reaction between the FeO and DRI followed by decarburization through the iron oxide of slag. Carbon has a significant effect on the kinetics of both stages, whereas the preheating temperature mainly influences the rate of decarburization between FeO and carbon inside the pellet.     

Note on reductionism in cognitive psychology: Reification of cognitive processes into mind, mind-brain equivalence, and brain-computer analogy.

This note brings together three phenomena leading to a tendency toward reductionism in cognitive psychology. They are (1) the reification of cognitive processes into an entity called mind; (2) the identification of the mind with the brain; and (3) the congruence by analogy of the brain with the digital computer. Also indicated is the need to continue studying the effects upon behavior of variables other than brain function. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Microstructures and Mechanical Properties of a New As-Hot-Rolled High-Strength DP Steel Subjected to Different Cooling Schedules

Controlled rolling followed by accelerated cooling was carried out in-house to study the microstructure and mechanical properties of a low carbon dual-phase steel. The objective of the study described here was to explore the effect of cooling schedule, such as air cooling temperature and coiling temperature, on the final microstructure and mechanical properties of dual-phase steels. Furthermore, the precipitation behavior and yield ratio are discussed. The study demonstrates that it is possible to obtain tensile strength and elongation of 780 MPa and 22 pct, respectively, at the two cooling schedules investigated. The microstructure consists of 90 pct ferrite and 10 pct martensite when subjected to moderate air cooling and low temperature coiling, such that the yield ratio is a low 0.69. The microstructure consists of 75 pct ferrite and 25 pct granular bainite with a high yield ratio of 0.84 when the steel is directly cooled to the coiling temperature. Compared to the conventional dual-phase steels, the high yield strength is attributed to precipitation hardening induced by nanoscale TiC particles and solid solution strengthening by high Si content. The interphase precipitates form at a suitable ledge mobility, and the row spacing changes with the rate of ferrite transformation. There are different orientations of the rows in the same grain because of the different growth directions of the ferrite grain boundaries, and the interface of the two colonies is devoid of precipitates because of the competitive mechanisms of the two orientations.     

Judicial Application of Daubert to Psychological Syndrome and Profile Evidence: A Research Note.

The authors present previously unreported results from a nationwide survey (N=325) of state trial judges (S. I. Gatowski et al., 2001) that was conducted pre-Kumho. The authors report how the 1993 Daubert guidelines were applied to psychological syndrome and profile evidence, and the impact of the decision on the admissibility of such evidence. They found that judges' views of and experience with psychological testimony varied widely and that most judges neither understood nor applied the more technical Daubert guidelines, such as falsifiability and error rate, when assessing psychological evidence. Overall, the findings suggest that Daubert's impact on the admissibility of psychological syndrome and profile testimony is negligible and that most judges are more comfortable with pre-Daubert standards when this type of testimony is proffered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Failure to find latent spatial learning in the Morris Water Task: Retraction of Jacobs, Zaborowski, and Whishaw (1989).

Retracts W. J. Jacobs et al (see record 1989-14538-001) because of a failure to find latent spatial learning in the Morris Water Task using the same method. In addition, reexamination of the earlier study revealed that if discarded data from 2 rats with abnormally high scores had been included in the analysis, the results would have been nonsignificant. Methodological confounds may also have contributed to the earlier results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Direct delivery of platinum-based antineoplastics to the central nervous system: a toxicity and ultrastructural study

Platinum drugs are playing an increasingly major role in cancer treatment, but systemic administration of these agents has resulted in significant toxicity. To examine the effects of cisplatin and two newer agents, iproplatin and carboplatin, we injected the agents directly into the cerebrospinal fluid of rats and found that neurotoxic reactions resulted from doses of cisplatin (10 nmol) much lower than those of iproplatin (40 nmol) or carboplatin (80 nmol). Moreover, central nervous system tissue appeared to be less adversely affected by direct exposure to carboplatin since chronic toxicity was not observed in any of the animals receiving carboplatin until a lethal dose was reached. Furthermore, only the animals receiving cisplatin showed histologic damage in their spinal cords, and ultrastructural studies confirmed that while significant abnormalities were observed in the spinal cords of rats receiving 40 nmol cisplatin, no architectural changes were detected in the spinal cords of animals receiving 240 nmol carboplatin. We conclude that platinum drugs can be delivered intrathecally to achieve a much greater concentration of active drug than can be achieved by intravenous administration and that carboplatin appears to be the most suitable platinum-based drug for use in systems delivering drugs directly to the brain and spinal cord.