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The Al–9Zr-0.9Sr master alloy was used to refine and modify the Al–7Si-0.5 Mg alloy, and to improve the refining and modification effects, the Al–9Zr-0.9Sr master alloy was carried out melt spinning treatment. The second phase particles in the ribbon are smaller and more evenly distributed than those in the ingot. The Al–Zr–Sr inoculation showed excellent refining and modification effects on Al–7Si-0.5 Mg alloy, and in the range of 1 wt.%∼4 wt.%, the refining effect was gradually enhanced with the increase of the inoculant dosage. The morphology and size of particles in inoculant have significant effects on the refinement and modification effects of the inoculant. The X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and selected area electron diffraction (SAED) results showed that in Al–7Si-0.5 Mg matrix alloy, (Al, Zr, Si) instead of Al3Zr was used as the heterogeneous nucleation substrate of α-Al to refine the grains. The Sr element in the master alloy was mainly used to modify eutectic silicon, and melt spinning could effectively improve its modification effect on eutectic silicon. With the increase of inoculant dosage, the mechanical properties of the alloy were gradually improved. However, when the dosage was increased to 4 wt.%, some large rod-like particles appear due to the excessive Zr element, resulting in a decrease in elongation.

The in-situ NdB6-Al11Nd3/Al inoculants were prepared by melt-spinning technology. The effects of cooling rate on the size and morphology of the NdB6 particles were researched. With the decrease of cooling rate, the average particle size increases, and the particle morphologies were changed from spherical to cubic gradually. The effects of the in-situ NdB6-Al11Nd3/Al inoculants on the evolvement of microstructure and mechanical properties of Al-5.8Cu-0.3Mn alloy were investigated in detail. The results of OM showed that the NdB6-Al11Nd3/Al inoculants had obvious refining effect on the Al-5.8Cu-0.3Mn alloy. The inoculants prepared at the highest cooling rate showed the best refining effect. The refining mechanism was studied by HRTEM. And the analysis results indicated that the in-situ NdB6 particles could form a good coherent interface with α-Al matrix, and thus played a role in the heterogeneous nucleation of the matrix. In addition, the excess rare-earth neodymium could also effectively refine grains and reduce the hydrogen porosities. The tensile strength of Al-5.8Cu-0.3Mn alloy was improved from 435 to 506 MPa, and the elongation was increased from 8.4 to 10.4%.

The properties of reinforcing particles, preparation technology and interfacial bonding between reinforcing particles and the matrix are crucial factors affecting the properties of particle-reinforced composites. In this paper, in-situ CaB 6 nanoparticles were prepared by melt-spinning and CaB 6 /Al–Cu–Mn nanocomposites with uniform distribution of reinforcing particles in the matrix were prepared with the aid of ultrasonic vibration. The effects of CaB 6 amounts on the microstructure and properties of the composites were studied. The distribution of CaB 6 particles in the matrix was analyzed by SEM. The results indicated that the dispersibility of CaB 6 nanoparticles in 1 vol.% and 2 vol.% CaB 6 /Al–Cu–Mn nanocomposites was better than that in 3 vol.% CaB 6 /Al–Cu–Mn nanocomposites. The CaB 6 /Al interface was studied by HRTEM and first-principles calculation. The results indicated that CaB 6 and α-Al could form a coherent interface, and the interfacial energies of the CaB 6 /Al interfaces were very low. The CaB 6 particles significantly improved the room and high temperature properties of the Al–Cu–Mn alloy.

To solve the problem of poor corrosion and wear resistance of Mg-Li alloys, Fe-based amorphous coatings were prepared by high velocity oxygen-fuel spraying technology (HVOF) on the LA141 magnesium alloy substrate with a Ni60 intermediate layer. The microstructure and performance of Fe-based amorphous coatings with different oxygen flow and kerosene flow were characterized and analyzed. The results demonstrate that there is an optimal oxygen/kerosene ratio where the porosity of Fe-based amorphous coating is the lowest. Moreover, the amorphous content increases with the decrease in the oxygen/kerosene ratio. In particular, when the oxygen flow is 53.8 m3/h and the kerosene flow is 26.5 L/h, the Fe-based amorphous coating possesses the lowest porosity (0.87%), the highest hardness (801 HV0.1), the highest bonding strength (56.9 MPa), and an excellent corrosion and wear resistance. Additionally, it can be seen that the Fe-based amorphous coating is composed of amorphous splats and amorphous oxides, but the Ni60 intermediate layer exhibits an amorphous and crystalline multi-phase structure. The high bonding strength of the coating is attributed to the low porosity of Fe-based amorphous coating and the localized metallurgical bonding between different layers. Finally, the mechanisms on corrosion and wear of Fe-based amorphous coatings are also discussed.

Combinatorial testing is an efficient test method, which can achieve high test coverage with as few test cases as possible. However, there are a large amount of test cases of combinatorial testing in industrial practice. If all the test cases are applied to executing, it takes a vast time and cost. How to select a subset of test cases which can guarantee failure detection rate is a common problem. In this paper, we introduce a novel technique for test case prioritization of combinatorial testing based on supervised machine learning. Our approach considers the test results of a small t-way covering array and the machine learning algorithm SVM is used to learn the test results first. Then SVM is used to predict a large t-way covering array. The test cases in the large t-way covering array are ordered according to the predicted results. The test cases which can lead failures in system under tests are ordered ahead. They own the priority. A subset of the ordered covering array which is selected from the start of the covering array can replace the whole covering array with time and cost saved reasonably. Our approach is evaluated by means of comparing the covering arrays which are ordered by SVM and the random ordering. Our results imply that our technique improves the failure detection rate significantly.

Mo, Zr, and Y with low diffusion coefficients in Al matrix were used to improve the high-temperature properties of the Al–5.8Cu–0.3Mn–0.2Mg alloy. The effects of these microalloying elements on the microstructures of the Al–5.8Cu–0.3Mn–0.2Mg alloy were investigated with the aid of optical microscopy and high-resolution transmission electron microscope (HRTEM). The HRTEM images and selected area electron diffraction patterns indicated that L12-Al3(Zr, Y), Al3Zr, Al3Y, and Al12Mo could precipitate in the process of solid solution treatment after adding Mo, Zr, and Y. These Mo-, Zr-, and Y-containing precipitates were stable at high temperatures and could slow the coarsening rate of θ′ precipitates at high temperatures. The tensile strength of the Al–5.8Cu–0.3Mn–0.2Mg alloy modified by Mo, Zr, and Y microalloying elements was improved significantly at both room and high temperatures. The strengthening mechanisms were discussed in detail.

Ceramic nanoparticles reinforced aluminum matrix composite is a kind of promising materials in industrial production. However, its preparation is difficult due to the poor wettability between Al melt and ceramic particles and severe particle aggregation tendency. In this paper, the in-situ NdB6/Al–5Cu-0.3Mn nanocomposites were successfully prepared with the aid of melt spinning technology and ultrasonic vibration. Optical microscopy (OM), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to observe the microstructures of nano-NdB6/Al ribbons and NdB6/Al–5Cu-0.3Mn nanocomposites. The observation results were as follows: (1) more than 80% of the prepared NdB6 particles were nanoscale; (2) the NdB6 particles could be uniformly distributed in the Al–5Cu-0.3Mn alloy; (3) the NdB6 particles had the effects of grain refinement and dispersion strengthening on the Al–5Cu-0.3Mn alloy; (4) the NdB6 particles had a certain orientation relationships with α-Al. The tensile strength of Al–5Cu-0.3Mn alloy strengthened by the NdB6 particles was improved significantly. The strengthening mechanisms were investigated in detail.

The in-situ Al3Nb-NbB2-NbC/Al inoculant (Al-5Nb-0.75B4C) ingots and ribbons were prepared with Al-Nb and B4C powers to refine the Al-Cu-Mn alloy. The Al3Nb-NbB2-NbC/Al inoculant ribbons showed excellent inoculant effect, which modified the dendrite crystals to equiaxed crystals and refined the grains from ~100 µm to ~30 µm. The transmission electron microscopy (TEM) images of the Al-Cu-Mn alloys reveal that the θ′ phases were refined from ~83 nm to ~40 nm and their number densities were also increased significantly. The selected area electron diffraction (SAED) patterns indicate that there are orientation relationships (ORs) between α-Al and Al3Nb, NbB2 and NbC, which suggest that these particles possess nucleation potency to α-Al. After inoculated by 1% Al3Nb-NbB2-NbC/Al ribbons, the ultimate tensile strength and elongation of the Al-Cu-Mn alloy were improved from 435 MPa and 8.4% to 514 MPa and 11.5%, respectively. The welding microstructure and property of the Al-Cu-Mn alloy inoculated by 1% Al3Nb-NbB2-NbC/Al inoculant were also improved significantly.

In this study, a heteroatom-doped porous biochar from waste biomass was prepared via a facile self-sacrificial template strategy for enhanced electrochemical capacitive performance. Numerous narrow pores and carbonized frameworks were formed by hydrothermally decomposing the unstable components in the biomass, which were further broadened to micropores and even larger mesopores through a molten salt activation method. The synthesized porous biochar displayed apparently increased specific surface area, up to 1138 m2 g−1, well-developed porous structure, and moderate heteroatom doping (5.35 at.% O and 1.02 at.% N), which offered more active storage sites and charge capacities. Consequently, the modified biochar exhibited significantly enhanced specific capacitance of 447 F g−1 at 0.2 A g−1, which was 1.6 and 6.0 times higher than that of the samples carbonized directly by molten salt and inert reduction methods, respectively. The findings indicate that the facile self-sacrificial template synthetic route of biochar does not only provide larger pores for reducing the ion diffusion resistance, but also introduces heteroatoms into the carbon frame to increase charge mobility. Moreover, the assembled two-electrode symmetric supercapacitor presented not only a specific capacitance of 367 F g−1 with an energy density of 12.75 Wh∙kg−1 but also an excellent stability after 10000 cycles.

Summary form only given. In this paper, the model of the output voltage for the cantilever-like sensor has been founded and the relationship between the output voltage and the external load has been determined, according to the inverse-magnetostrictive effect, the flexure mode, and the Jiles-Atherton model. The output voltage is relative with the bias magnetic field and the information of the sample, which is dependent on the contact force, the contact area and the friction coefficient, in addition to the Galfenol sheet material parameters. The Galfenol sheet material parameters include the length of Galfenol sheet, the Young's modulus, the Poisson's ratio, the relative permeability, the density of Galfenol sheet, the sectional moment of inertia, and the tilted angle of Galfenol sheet. The output voltage of the cantilever-like sensor is caused by the change of magnetic induction in Galfenol material.

Fe - Ga thin films were prepared by DC magnetron sputtering on Si (100) substrate and an alloy target consisting of Fe 81 Ga 19 was used. X-ray diffraction techniques were used to quantify the strain in the Fe - Ga thin films by measuring the interplanar spacings of select crystallographic planes. The interplanar spacing, d, for the family of Fe - Ga {211} planes was measured. Using the well-established sin 2ψ technique, the residual stress of the Fe - Ga thin films was calculated. It has been found that the stress for Fe - Ga thin films quickly increases with increasing the sputtering power. The residual stress of thin films is almost unchanged in the range of 220-440 nm, and then it decreases with increasing the thickness of thin films.

Based on the analysis of the magnetostriction for Terfenol-D composites, Terfenol-D 2-2 magnetostrictive composites have been prepared with laminations perpendicular to [1 1 2] axes. Then one of the samples was annealed in the vacuum at 423K for 15 min at the magnetic field of 240 kA/m, which is along the direction of laminations and vertical to the [1 1 2] axes of the specimen. The static magnetostriction l and dynamic magnetostrictive lambda coefficient d(33) of samples were measured under the compressive stress of 0, 2, 4, 6 and 8 MPa. Effects of the compressive stress and the magnetic field heat treatment on the magnetostriction lambda have been investigated. It is found that the magnetostriction of 2-2 composites can be improved under the compressive stress when the magnetic field is larger than 20 kA/m. The magnetostriction of 2-2 composites with the magnetic field heat treatment increases under compressive stress, and it can reach 1390x10(-6) at the magnetic field of 200 kA/m and under the compressive stress of 4 MPa, much larger than the value of 860x10(-6) without the magnetic field heat treatment. The highest magnetostriction of the 2-2 composite with the magnetic field heat treatment can reach 1530x10(-6). The dynamic magnetostrictive coefficient d(33) of 2-2 composites with the magnetic field heat treatment have been improved, compared with that without magnetic field heat treatment. The maximum value of d(33) of the sample with magnetic field heat treatment is 71% larger than that without magnetic field heat treatment. (C) 2007 Elsevier B.V. All rights reserved.

Phase equilibria of the Tb-Dy-Zn system were determined in an isothermal section at 500 degrees C and vertical sections of TbZn-DyZn and (Tb0.4DY0.6)(0.6)Zn-0.4-(Tb0.4DY0.6)(0.45)Zn-0.55 by using optical microscopy, X-ray diffraction analysis, electron probe microanalysis and differential thermal analysis techniques. The isothermal section possesses nine single-phase regions and eight two-phase regions. There are seven intermetallic phases: (Tb,Dy)Zn, (Tb,Dy)Zn-2, (Tb,Dy)Zn-3, (Tb,DY)(3)Zn-11 (Tb,Dy)(13)Zn-58, (Tb,DY)(2)Zn-17 and (TbDY)Zn-12. No (Tb,DY)(3)Zn-22 phase exists in the ternary system. The vertical section of TbZn-DyZn in Tb-Dy-Zn system contains two single-phase regions. Investigation of the vertical section of (Tb0.4DY0.6)(0.6)Zn-0.4-(Tb0.4DY0.6)(0.45)Zn-0.55 indicates that the (Tb,Dy)Zn single-phase region is a little shifted into Zn-rich region. (c) 2005 Elsevier B.V. All rights reserved.

Based on the atomic model of rare earth-Fe 2 (RFe 2 ) compounds, the magnetoelastic model of Laves phase RFe 2 compounds has been proposed and it can be used to explain the strain caused by both a magnetic field and a compressive stress. The magnetic field dependence of Young's modulus under different bias stress has been founded according to magnetoelastic theory. It is found that the calculating result is in a good agreement with the experimental one for Tb 0.3 Dy 0.7 Fe 2 alloy. This result indicates that the founded model can describe the relation between Young's modulus and magnetic fields under different bias stress.

Phase equilibria of the Tb-Dy-Zn system were determined in an isothermal section at 500 degrees C and vertical sections of TbZn-DyZn and (Tb0.4DY0.6)(0.6)Zn-0.4-(Tb0.4DY0.6)(0.45)Zn-0.55 by using optical microscopy, X-ray diffraction analysis, electron probe microanalysis and differential thermal analysis techniques. The isothermal section possesses nine single-phase regions and eight two-phase regions. There are seven intermetallic phases: (Tb,Dy)Zn, (Tb,Dy)Zn-2, (Tb,Dy)Zn-3, (Tb,DY)(3)Zn-11 (Tb,Dy)(13)Zn-58, (Tb,DY)(2)Zn-17 and (TbDY)Zn-12. No (Tb,DY)(3)Zn-22 phase exists in the ternary system. The vertical section of TbZn-DyZn in Tb-Dy-Zn system contains two single-phase regions. Investigation of the vertical section of (Tb0.4DY0.6)(0.6)Zn-0.4-(Tb0.4DY0.6)(0.45)Zn-0.55 indicates that the (Tb,Dy)Zn single-phase region is a little shifted into Zn-rich region. (c) 2005 Elsevier B.V. All rights reserved.