In this work, ultra-low dilution rate Inconel 625 coatings with a thickness of ~534.4 μm were prepared by high-speed laser cladding technique on the Q245R steel. The XRD and TEM results show that the Inconel 625 coatings are mainly composed of the Nb and Mo-enriched laves phase with hexagonal close-packed (HCP) structure and the γ-Ni phase with face-centered-cubic (FCC) structure. The cellular crystal, column crystal, and equiaxed dendritic crystal were observed in the bottom, middle, and top of the Inconel 625 coatings from SEM results, respectively. The wear resistance and corrosion resistance of Q245R steel are significantly improved by high-speed laser cladding Inconel 625 coatings. In addition, the low dilution rate is beneficial for improving the wear and corrosion resistance of high-speed laser cladding Inconel 625 coatings. These findings may provide a method to design the wear and corrosion resistance of coatings on steel's surface.

Porous intermetallic membrane with extensive interconnected pores are potential candidates as functional materials for high-temperature particulate matter (PM) capturing. However, fabrication of intermetallic membrane with a combined performance of high filtration efficiency and high-temperature oxidation resistance remains a challenge. To tackle this issue, a hierarchical micro-/nano-dual-scale sized pores was constructed on the inner cell walls of a porous support through mutual diffusion and chemical reaction. Benefited from its hierarchical micro/nano-dual-scaled pore structural features, the high Nb containing TiAl-based porous composite microfiltration membrane demonstrates ultrahigh PM_>2.5removal efficiency (99.58%) and favorable oxidation/sulfidation performance at high temperature. These features, combined with our experimental design strategy, provide insight into designing high-temperature PM filtration membrane materials with enhanced performance and durability.

Microstructure and deformation mechanisms at a nanoindentation in the lamellar colony of high Nb containing TiAl alloy have been studied using the focused ion beam and the transmission electron microscopy. Considerable deformation twins are observed around the nanoindentation, and a strain gradient is generated. A continuous change in the bending angle of the lamellar structure can be derived, and a strain-induced grain refinement process is observed as various active deformations split the γ grains into subgrains. In addition to all possible deformation mechanisms (ordinary dislocation, super-dislocation and deformation twining) activated due to the heavy plastic deformation, a 6-layer hexagonal (6H) long-period stacking ordered structure is identified for the first time near the contact zone and is thought to be closely related to the glide of partial dislocations.

There is widespread attention to surface profile and modification of 304 stainless steel for research development and application. Here, a successful electrolytic plasma processing (EPP) technique has been developed for both surface pretreatment and coating deposition of 304 stainless steel. Representative images confirm that the number of the pits increases and the ravines gradually disappear on the steel pretreated by EPP with the increase of processing time and applied voltage. Moreover, there is an obvious enhancement in surface roughness of 304 stainless steel after EPP pretreatment. In the case of coating deposition, the further EPP modification conducted on the pretreated sample offers a simple and effective technique for the production of zinc coatings having the features of full coverage and homogeneous distribution. The results show that a zinc coating with a thickness of approximately 0.5 μm can be obtained on the 304 stainless steel by means of EPP for only 60 s.