Mechanical alloyed Ti–Cu–Ni–Si–B amorphous alloys with significant supercooled liquid region

This study examined the glass formation range of Ti_94–x–yCu_xNi_ySi₄B₂ alloy powders synthesized by mechanical alloying technique. According to the results, after 5–7 h of milling, the mechanically alloyed powders were amorphous at compositions with (x+y) equal to 20–40%. For the compositions with (x+y) larger than 45% or smaller than 10%, the structure of ball-milled powders is a partial amorphous single phase or coexistent partial amorphous and crystalline phases, respectively. The thermal stability of the amorphous powders was also investigated by differential thermal analysis. As the results demonstrated, several amorphous powders were found to exhibit a wide supercooled liquid region before crystallization. The temperature interval of the supercooled liquid region defined by the difference between T_g and T_x, i.e. ΔT(=T_x–T_g), are 52 K for Ti₇₄Ni₂₀Si₄B₂, 74 K for Ti₆₄Ni₃₀Si₄B₂, 58 K for Ti₆₄Cu₂₀Ni₁₀Si₄B₂, and 61 K for Ti₇₄Cu₁₀Ni₁₀Si₄B₂.     

Strategy, IT applications for planning and control, and firm performance: The impact of impediments to IT implementation

Our study examined the association among strategy, the extent of IT applications to 12 planning and control functions, and firm performance. Special attention was paid to the moderating effect on these relationships of 15 technical, human, and organizational impediments to IT implementation. We analyzed survey data obtained from 296 Taiwanese companies, supplemented by financial data from publicly disclosed financial reports. Results indicated that strategy significantly influenced the extent of IT applications for planning and control. In turn, the extent of IT applications had a significant direct effect on firm performance, while the direct effect of strategy was insignificant. The relationship between strategy and the extent of IT applications, and between the latter and firm performance were both stronger when the level of impediments to IT implementation was low. The findings went beyond these general relationships to reveal systematic differences in the specific IT applications and impediments of firms pursuing different strategies.     

Effects of the addition of Pd on the hydrogen absorption–desorption characteristics of Ti33V33Cr34 alloys

The hydrogen absorption–desorption performance of the body-centered-cubic (bcc) Ti–V–Cr–Pd alloys have been investigated. Ti₃₃V₃₃Cr₃₄ ingots with 0, 0.05, 0.5 at.% Pd were prepared by arc melting. X-ray diffraction (XRD) revealed that all of these alloys were homogeneous bcc solid solutions. Pd-containing (0.05, 0.5 at.% Pd) Ti–V–Cr alloys have better initial activation properties than those without Pd, and the desorption plateau pressure of the (Ti₃₃V₃₃Cr₃₄)_99.5Pd_0.5 alloy was substantially higher than that of the alloy without Pd. It is also found that the hysteresis difference is smaller in these alloys and degradation of hydrogen absorption capacity becomes steady after the 25th cycling test. (Ti₃₃V₃₃Cr₃₄)_99.5Pd_0.5 alloy exhibits large hydrogen absorption and desorption capacity of up to 3.42 and 2.07 mass% at 353 K, respectively.     

Mass production of alloy bulk by isothermal evaporation casting process

An innovative method, isothermal evaporation casting process (IECP), is developed to produce Mg₂Ni alloy for mass production in this work. In the past, high vapor pressure of Mg was considered as a disadvantage for producing pure Mg₂Ni alloy. However, this characteristic was used to develop a refinement procedure to separate primary Mg₂Ni alloy from Mg/Mg₂Ni eutectic matrix. Characteristics of as-cast specimens measured by X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES) and electron probe X-ray microanalyzer (EPMA) reveal that mass production of single phase Mg₂Ni alloy was successfully fabricated by IECP. For every 4.0 kg of raw materials, alloy bulk was extracted at a yield of about 65%. The hydrogen storage capacity of the well-activated Mg₂Ni alloy reaches 3.58 wt% at 300 °C under 40 atm H₂ atmosphere which is close to the theoretical capacity of 3.6 wt%.