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Purpose: The aim of this study is to investigate the effects of Al2O3 mass fraction on the corrosive-wear and electrochemical performance of NiTi coating in 3.5% NaCl solution. Design/methodology/approach: The NiTi–xAl2O3 coatings were fabricated on S355 steel by laser cladding, and their corrosive-wear and electrochemical performance were investigated using a wear tester and electrochemical workstation, respectively. Findings: The wear rates of NiTi–5%Al2O3, –10%Al2O3 and –15%Al2O3 coatings are 82.33, 54.23 and 30.10 µm3 mm−1 N−1, respectively, showing that the wear resistance of NiTi–15%Al2O3 coating is the best. The wear mechanism is abrasive wear, which is attributed to the increase of coating hardness by the Al2O3 addition. The polarization resistance of NiTi–5%Al2O3, –10%Al2O3 and –15%Al2O3 coatings is 3,639, 5,125 and 10,024 O cm2, respectively, exhibiting that the NiTi–15% Al2O3 coating has the best corrosion resistance. Originality/value: The roles of Al2O3 in the corrosive-wear and electrochemical performance of NiTi–xAl2O3 coating were revealed through the experimental investigation. Peer review: The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2024-0044/ [ABSTRACT FROM AUTHOR]

Ni625-xTiC coatings were prepared on 45 steel by laser cladding to improve its corrosive-wear and electrochemical performances. The microstructure, phase composition and hardness of obtained coatings were analyzed using a super-depth field microscope, x-ray diffraction, and microhardness tester, respectively. The effects of TiC mass fraction on the corrosive-wear and electrochemical behaviors in 3.5% NaCl solution were investigated. The results show that the Ni625-xTiC coatings are mainly composed of γ-Ni, TiC, Cr23C6, Cr7C3, Fe3Mo, FeTi and Nb2C phases, and the coating hardness increases with the TiC mass fraction, which is 3 times that of substrate. The wear rates of Ni625-0%TiC, -5%TiC, -10%TiC and -15%TiC coatings are 65.86, 55.09, 47.92 and 42.15 μm3 mm−1 N−1, respectively, showing that the wear resistance of Ni625-15%TiC coating is the best. The wear mechanism is primary abrasive wear, accompanied with adhesive wear and pitting corrosion. Moreover, the polarization resistance Rp of Ni625-0%TiC, -5%TiC, -10%TiC and -15%TiC coatings is 1.136 × 105, 1.459 × 105, 8.619 × 104, 5.698 × 104 Ω cm2, respectively, showing that the Ni625-5%TiC has the best corrosion resistance. [ABSTRACT FROM AUTHOR]

This paper proposes a casting improvement process to enable the casting of Al-Cu alloy cylinder heads to achieve the required quality. The hot tearing defects generated in the fire face of the cylinder head during casting were simulated using MAGMA software. The simulation results show that the large wall thickness transition difference in the fire face of the cylinder head is the reason for the large temperature and stress gradient during solidification. Therefore, the first solution was optimised by forming the fire face as a whole into a flat plate, but the fire face centre area stress is still too high. The second optimisation option optimises the cold iron structure of the fire face, the probability of cracking in the fire face is reduced to 17%. These results have important reference significance for the optimisation of the Al-Cu alloy cylinder head hot tearing problem. [ABSTRACT FROM AUTHOR]

Ni625–xCr 3 C 2 coatings were prepared on 45 steel by laser cladding to improve its tribocorrosion and electrochemical property. The microstructure, phases and hardness of obtained coatings were analyzed using a super–depth field microscope, X–ray diffraction, and microhardness tester, respectively, and the effects of Cr 3 C 2 mass fraction on the tribocorrosion and electrochemical properties of Ni625–xCr 3 C 2 coatings in 3.5 % NaCl solution were investigated. The results show that the Ni625–xCr 3 C 2 coatings are mainly composed of γ–Ni, Fe 3 C, Cr 3 C 2 , Mo 2 C, Cr 7 C 3 and Cr 23 C 6 phases, and their coating hardness increases with the Cr 3 C 2 mass fraction, which are almost three times that of substrate. The coefficients of friction and wear rates of Ni625–5%Cr 3 C 2 , −10%Cr 3 C 2 and − 15%Cr 3 C 2 coatings are reduced compared with the Ni625 coating, and the wear mechanism is primary abrasive wear, accompanied with adhesive wear and pitting corrosion. Moreover, the polarization resistance of Ni625–5%Cr 3 C 2 , −10%Cr 3 C 2 and − 15%Cr 3 C 2 coatings are higher than that of Ni625 coating, showing that the corrosion resistance of Ni625–10%Cr 3 C 2 coating was the best among the four kinds of coatings. • The grains of Ni625–xCr 3 C 2 coatings are refined by the addition of Cr 3 C 2. • The hardness of Ni625–xCr 3 C 2 coatings is increased with the Cr 3 C 2 mass fraction. • The wear mechanism of Ni625–xCr 3 C 2 coatings is abrasive wear, adhesive wear and pitting corrosion. • The polarization resistance and charge transfer resistance are increased with the Cr 3 C 2 mass fraction. [ABSTRACT FROM AUTHOR]

A Grimm-type glow discharge ion source, operated in the microsecond pulsed mode, has been interfaced to a commercial time-of-flight mass spectrometer. Ion transport from the source to the mass spectrometer, an inherent limitation of a Grimm source and mass spectrometer combination, was evaluated. The primary discharge operating conditions found to influence transport efficiency were gas flow rate and source pressure. The configuration of the Grimm-type source also influenced ion transport, including use of a gas-directing sleeve device. The effect of transport efficiency was separated into two components: (1) total ion signal and (2) temporal resolution. The latter is an advantage afforded by use of a pulsed glow discharge source and time-of-flight spectrometer, which allows discrimination against interfering gaseous background ions by appropriate ion sampling time. Shown as an example is the identification of trace magnesium from potential background interference using an optimized source configuration based on this temporal resolution method. [ABSTRACT FROM AUTHOR]

Discusses various aspects of pulsed glow discharge (GD) techniques for atomic generations. Pulsed GD properties; Ability of GD to convert solid samples into gas-phase atoms; Applications of GD spectroscopies; General scheme of GD source for optical emission; Time-resolved spectroscopy of GD; Analytical considerations for GD techniques; Other possibilities.

Examines the application of microsecond pulsed Grimm glow discharge (GD) atomic emission spectrometry for depth profiling of thin films. Effects of pulsed conditions on depth profiling performance of zinc and copper coatings on steel; Linear calibration curves of coating thickness for zinc and copper on steel.

In this paper, the second harmonic generation (SHG) method, a non-linear ultrasonic technique, is employed to investigate the interface debonding of steel-concrete composites. The quadratic parameter of non-linear constitutive relationship for the steel-concrete composites is adopted as a measure of the debonding between a steel component and a concrete component. The quadratic parameter is calculated based on the amplitude measurements of probing ultrasonic waves and the corresponding second harmonic generated by the non-linear response of the debonded steelconcrete interface. The ultrasonic experiments are conducted on both scaled-down laboratory samples and full-size structures. Results from both experiments show that the defined parameter is highly correlated with the debonding condition of the composite interface, indicating an excellent feasibility for its use in the detection of the variation of interface microstructure. The SHG experimental results are further compared with results from the amplitude attenuation, a conventional ultrasonic method. It is shown that the change in the defined parameter is orders of magnitude larger than the traditional attenuation coefficient. The results of the comparison demonstrate the higher sensitivity of the developed SHG method in terms of the assessment of interface debonding of steel-concrete composites, particularly in the early phase of structural deterioration. [ABSTRACT FROM AUTHOR]

A novel set of multifunctional optically active π-conjugated polymers incorporating perylenyl moieties, were designed and synthesized. Chirality transfer and amplification from chiral unit to the mainchain backbone in dilute solution was achieved, which was closely related to the stereocenter in the pendant of a π-conjugated polymer. In addition, annealed films of these polymers exhibited near-infrared emission by direct absorption of visible light, resulting from the introduction of a strong fluorophore perylenyl moiety. Such a design strategy opens up new perspectives for the future development of novel optically active materials with near-infrared emission for photonic applications. [ABSTRACT FROM AUTHOR]

Islanding detection is a significant technical barrier to the distributed generation (DG) industry. When islanding occurs, the inverter current of DG has a strong correlation with load voltage of DG. With respect to the correlation, this paper proposes an islanding detection method (IDM) based on periodic matching of the sequence perturbation. In this periodic code matching detection method, a periodic sequence is introduced to perturb the inverter current amplitude. The IDM can be achieved by calculating periodic matching degree between the islanding detection coefficient and the sequence. The influence on IDM imposed by sequence characteristics and load variation is also discussed in this paper. According to IEEE Std. 1547, an islanding detection model is designed and simulated in this paper. The simulation and experiment results indicate a strong ability to anti-harmonic noise when the 1-0 non-zeroing sequence with six bits is selected as the perturbation sequence. The proposed method introduces little damage to grid. In the normal range of voltage and frequency, this method can detect the islanding of DG reliably and effectively even if load varies. [ABSTRACT FROM AUTHOR]

The properties of spray-induced vortex-like structures for asymmetric pressure swirl atomizer were studied experimentally with different injection pressures. The high-speed Particle Imaging Velocimetry (PIV) was used to study the spray characteristics such as velocity and vorticity. The vortex centers were identified by velocity weighted vorticity. The translational velocity components of vortex centers were computed from its displacement divided by the time interval. For five different pressure conditions, the motion trajectories of vortex center were the same in an earlier period of spray, but were different in a later period of spray. The normalized translational velocity of vortex center and normalized time were introduced to compare with vortex ring model. The results indicated that the normalized axial translational velocity decreased with increasing normalized time, which converged to the predictions of the model in long time limit where α = -0.75 in the turbulent case. However, the results for the normalized radial translational velocity were different from the predictions of the model. The normalized radial translational velocity decreased with the increase of the normalized time when the injection pressure was lower than a critical value, but it obviously increased with the increase of the normalized time in case of the injection pressure higher than the critical value. Furthermore, the average vorticities at the vortex center were obtained and increased with the increase of the injection pressure. This study provides references for developing spray theory and improving injection technology. [ABSTRACT FROM AUTHOR]