<Emphasis Type="Italic">Development of</Emphasis> an iron-base beryllium-strengthened alloy

The possibilities of beryllium-strengthened iron-base alloys have been pursued to achieve a commercial low-density, high-strength alloy for service to 1400°F.     

Electrochemical characteristics of amorphous MgTixNi （x = 0,0.1, and 0.2） hydrogen storage alloys

MgTi _x Ni (x = 0, 0.1, and 0.2) alloys were successfully prepared by mechanical alloying (MA), and the influence of milling time on the electrochemical characteristics of the electrodes was discussed. MgTi _x Ni alloys after 90 h milling displayed the best electrochemical performance. The X-ray diffraction patterns showed that the alloy ball-milled for 90 h was amorphous with a widened diffraction peak. The charge-discharge tests indicated that these alloys had good electrochemical activation properties, and the MgTi_0.2Ni alloy electrode exhibited the best cycle performance. The initial discharge capacity of the MgTi_0.2Ni alloy reached up to 401.1 mAh·g⁻¹, and the retention rate of capacity was 31.0% after 30 cycles, much higher than that of MgNi (17.3%). The Tafel polarization curves revealed that Ti addition could enhance the anticorrosion performance of these alloys in alkali solution, which was responsible for the ameliorated cyclic stability of these alloy electrodes.     

X-ray diffraction determination of root-mean-square displacements of atoms in <Emphasis Type="Italic">B</Emphasis>2 and <Emphasis Type="Italic">R</Emphasis> phases of titanium nickelide

Intensities of 15 fundamental and 11 superlattice reflections of the B2 phase have been measured in a titanium nickelide single crystal using X-ray Mo Kα radiation. Structure factors for these reflections and root-mean-square displacements of nickel and titanium atoms from the crystal-lattice sites have been calculated. The mean squared displacements of nickel atoms are equal to 〈u ²〉_Ni=0.087 ± 0.006 Ų; those of titanium atoms, 〈u ²〉_Ti = 0.039 ± 0.003 Ų. The temperature dependence of root-mean-square displacements in the B2 phase and in the temperature range of the B2 → R transformation has been determined. Root-mean-square atomic displacements in the R phase have been calculated. The Debye temperature has been determined and the root-mean-square atomic displacements in the B2 phase have been separated into static and dynamic ones.     

<Emphasis Type="Italic">An evaluation of</Emphasis> maraging steel sheet

Results of investigations into the metallurgical and mechanical behavior of 18Ni-9Co-5Mo maraging steel—one of a series of tough, high-strength alloys in a period of rapid development.     

<Emphasis Type="Italic">Recent Developments in</Emphasis> zinc blast-furnace technology

Improved zinc blast-furnace techniques—including the development of updraft sulfide sintering and utilization of charges containing up to 25% Pb—are reported. The installation and operational results of a new, large-furnace installation at Swansea, Wales, are described. Details of a vacuum method for improving the purity of the zinc—with lead impurities indicated to be as low as 0.4%—are included.     

<Emphasis Type="Italic">An evaluation of</Emphasis> disposable hot tops

The development of disposable hot tops has enabled a major steel producer to satisfy customer demands for wide killed-steel strip without having to resort to uneconomical practices.     

Biocompatibility of surface treated pure titanium and titanium alloy by<Emphasis Type="Italic">in vivo</Emphasis> and<Emphasis Type="Italic">in vitro</Emphasis> test

In the present study, commercial pure Ti and Ti-6Al-4V alloy specimens with and without alkali and heat treatments were implanted in the abdominal connective tissue of mice. Conventional stainless steel 316L was also implanted for comparison. After three months, their biocompatibility was evaluated byin vitro andin vivo experiments. Surface structural changes of specimens due to the alkali treatment and soaking in Hank’s solution were analyzed by XRD, SEM, XPS and AES. An apatite layer, which accelerates the connection with bone, was formed more easily on the alkali treated specimens than the non-treated specimens. The number of macrophages, which is known to increase as the inflammatory reaction proceeds, was much lower for the alkali and heat treated specimens than for the others. The average thickness of the fibrous capsule formed around the implant was much thinner for the alkali and heat treated specimens than for the others.     

Microstructure and mechanical properties of multi-principal component AlCoCrFeNiCu<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> alloy

By introducing Cu, AlCoCrFeNiCu _x (x values in molar ratio, x = 0, 0.1, 0.5, 1.0, 1.5, 2.0, and 2.5) alloys were designed and prepared. The effects of Cu on microstructure and properties of AlCoCrFeNi alloy were investigated. The introduction of Cu results in the formation of Cu-rich FCC solid solution phase when Cu content is low. There are two FCC solid solution phases, i.e., Cu-rich FCC solid solution phase and phase transformation-induced FCC solid solution phase, when the Cu content is more than 1.0. Both the yield stress and plastic strain of alloy show a turning point when the Cu content is 0.5. Among the seven alloys, Cu_0.5 alloy exhibits the largest yield stress of 1187 MPa and the lowest plastic strain of 16.01 %.     

Centrifugal casting processes of manufacturing <Emphasis Type="Italic">in situ</Emphasis> functionally gradient composite materials of Al-19Si-5Mg alloy

Cylindrical components of in situ functionally gradient composite materials of Al-19Si-5Mg alloy were manufactured by centrifugal casting. Microstructure characteristics of the manufactured components were observed and the effects of the used process factors on these characteristics were analyzed. The results of observations shows that, in thickness, the components possess microstructures accumulating lots of Mg₂Si particles and a portion of primary silicon particles in the inner layer, a little Mg₂Si and primary silicon particles in the outer layer, and without any Mg₂Si and primary silicon particle in the middle layer. The results of the analysis indicate that the rotation rate of centrifugal casting, mould temperature, and melt pouring temperature have evidently affected the accumulation of the second phase particles. Also, the higher the centrifugal rotation rate, mould temperature, and melt pouring temperature are, the more evident in the inner layer the degree of accumulation of Mg₂Si and primary silicon particles is.     

Mechanism of infiltration <Emphasis Type="Italic">of porous powder-metallurgy parts</Emphasis>

This article discusses the history, mechanism, and theory of infiltrating porous powder-metallurgy parts with molten metal.