In this study, laser surface remelting of an AlCoCrFeNi_2.1 high-entropy alloy was performed using a Yb:YAG laser. The effects of laser surface remelting on the phase structure, microstructure, Vickers hardness, frictional wear properties, and corrosion resistance of the high-entropy alloy were investigated. The remelted layer of the AlCoCrFeNi_2.1 high-entropy alloy was produced by remelting at 750 W laser power and formed a good metallurgical bond with the substrate. The X-ray diffraction results showed that the 750 W remelted layer consisted of face-centered cubic and body-centered cubic phases, which were consistent with the phases of the as-cast AlCoCrFeNi_2.1 high-entropy alloy, and a new phase was not generated within the remelted layer. Laser surface remelting is very effective in refining the lamellar structure, and the 750 W remelted layer shows a finer lamellar structure compared to the matrix. The surface hardness and wear resistance of the AlCoCrFeNi_2.1 high-entropy alloy were substantially improved after laser surface remelting. In a 3.5 wt.% NaCl solution, the laser-remelted surface had a larger self-corrosion potential and smaller self-corrosion current density, and the corrosion resistance was better than that of the as-cast high-entropy alloy.

The bond strength is a critical consideration for the plasma-sprayed NiCrBSi coatings. However, the conventional methods for testing the bond strength of NiCrBSi coatings always cost time and money. If there is a simple method that could predict the bond strength of the prepared NiCrBSi coatings without destroying the coatings, it would be significantly beneficial for industrial applications. In this work, a new method was proposed based on the total areas of the interfacial pores for the NiCrBSi coatings. The NiCrBSi coating was prepared by plasma spraying technology and the as-sprayed coating was subsequently remelted by plasma arc using the powers of 20 kW, 25 kW, and 30 kW, respectively. The interfacial microstructures, the size distributions and total areas of the interfacial pores, interfacial hardness, and bond strength of all prepared coating samples were investigated. After remelting, the number and the total area of interfacial pores decrease with increasing the remelting power. Correspondingly, the interfacial hardness and bond strength of coatings increase with increasing the remelting power The bond strength of coatings basically has a linear relationship with the total area of interfacial pores. The built relationship may be used to predict the bond strength of NiCrBSi coatings.

To prepare wrought magnesium alloys with excellent plastic deformation properties, Mg-3Sn-2Al-1Zn-0.6Nd alloys were prepared. A hot compression test of Mg-3Sn-2Al-1Zn-0.6Nd alloy was carried out on a thermo-mechanical simulator. The hot deformation behavior of the alloys was studied, and the constitutive equations and the processing map at the strain of 0.8 were established. The processing map exhibited the stable domain (temperature range of 320–350 °C and strain rate range of 0.001–0.04 s⁻¹) with the high power dissipation efficiency (>30%). A large number of fine dynamic recrystallization (DRX) grains and deformed twinning existed in the alloy after the hot deformation. The dominant texture of the Mg-3Sn-2Al-1Zn-0.6Nd alloy is //CD texture after the hot deformation. The continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) were the dominant recrystallization mechanisms, and {10$\overline{1}$2} extension twinning also occurred in the alloy during the hot deformation.

Stainless steel, due to its exceptional comprehensive properties, has been widely adopted as the primary material for liquid cargo tank containment systems and pipelines in liquefied natural gas (LNG) carriers. However, challenges such as hot cracking, excessive deformation, and the deterioration of welded joint performance during stainless steel welding significantly constrain the construction quality and safety of LNG carriers. While conventional tungsten inert gas (TIG) welding can produce high-integrity welds, it is inherently limited by shallow penetration depth and low efficiency. Magnetic field-assisted TIG welding technology addresses these limitations by introducing an external magnetic field, which effectively modifies arc morphology, refines grain structure, enhances penetration depth, and improves corrosion resistance. In this study, TIG bead-on-plate welding was performed on 304 stainless steel plates, with a systematic investigation into the dynamic arc behavior during welding, as well as the microstructure and anti-corrosion properties of the deposited metal. The experimental results demonstrate that, in the absence of a magnetic field, the welding arc remains stable without deflection. As the intensity of the alternating magnetic field intensity increases, the arc exhibits pronounced periodic oscillations. At an applied magnetic field intensity of 30 mT, the maximum arc deflection angle reaches 76°. With increasing alternating magnetic field intensity, the weld penetration depth gradually decreases, while the weld width progressively expands. Specifically, at 30 mT, the penetration depth reaches a minimum value of 1.8 mm, representing a 44% reduction compared to the non-magnetic condition, whereas the weld width peaks at 9.3 mm, corresponding to a 9.4% increase. Furthermore, the ferrite grains in the weld metal are significantly refined at higher alternating magnetic field intensities. The weld metal subjected to a 30 mT alternating magnetic field exhibits the highest breakdown potential, the lowest corrosion rate, and the most protective passive film, indicating superior corrosion resistance compared to other tested conditions.

Due to air pollution and energy shortages in the contemporary world, weight lighting for transportation vehicles and energy conservation, as well as emission reductions, are necessary to achieve carbon neutrality and fuel conservation