The uneven distribution and large size of the second phase weakens the effect of dispersion strengthening in ODS-W alloys. In this article, the W-Al₂O₃ composite powders were fabricated using a wet chemical method, resulting in a finer powder and uniformly dispersed Al₂O₃ particles in the tungsten-based alloy. The particle size of the pure tungsten powder is 1.05 μm and the particle size of W-0.2 wt.%Al₂O₃ is 727 nm. Subsequently, the W-Al₂O₃ alloy plates were successfully obtained by induction sintering and rolling processes. Al₂O₃ effectively refined grain size from powder-making to sintering. The micro-hardness of the tungsten alloy plates reached 512 HV_0.2, which is 43.7% higher than that of pure tungsten plates. The nano-hardness reached 14.2 GPa, which is 24.1% higher than that of the pure tungsten plate; the compressive strength reached 2224 MPa, which is 37.2% higher than that of the pure tungsten.

To improve the Al/Steel bimetallic interface, Eu was firstly added to the Al/Steel bimetallic interface made by liquid-solid casting. The effects of Eu addition on the microstructure, mechanical capacities, and rupture behavior of the Al/Steel bimetallic interface was studied in detail. As the addition of 0.1 wt.% Eu, the morphology of eutectic Si changed from coarse plate-like to fine fibrous and granular in Al-Si alloys, and the average thickness of the intermetallic compounds layer decreased to a minimum value of 7.96 μm. In addition, there was a more sudden drop of Fe in steel side and the Si in Al side was observed to be more than the other conditions. The addition of Eu did not change the kinds of intermetallic compounds in the Al/steel reaction layer, which was composed of Al₅Fe₂, τ₁-(Al, Si)₅Fe₃, Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases. The addition of the element Eu did not change the preferential orientation of the Al₅Fe₂, τ₁-(Al, Si)₅Fe₃, Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases, but refined the grain size of each phase and decreased the polar density of Al₅Fe₂ phase. Eu was mainly enriched in the front of the ternary compound layer (τ₆-Al₉Fe₂Si₂) near the Al side and steel matrix. The Fe and Al element distribution area tended to narrow in the interface after the addition of 0.1 wt.% Eu, which is probably because that Eu inhibits the spread of Al atoms along the c-axis direction of the Al₅Fe₂ phase and the growth of Al₁₃Fe₄, τ₅-Al₇Fe₂Si, and τ₆-Al₉Fe₂Si₂ phases. When the Eu content was 0.1 wt.%, the shear strength of the Al/Steel bimetal achieved a maximum of 31.21 MPa, which was 47% higher than the bimetal without Eu.

In the present work, a low-pressure chemical vapor deposition (LPCVD) Ti_0.17Al_0.83N and state-of-the-art arc ion plating PVD-Ti_1−xAl_xN (x = 0.25, 0.55, 0.60, 0.67) coatings were deposited on cemented carbide substrate. The morphological, structural, and electrochemical properties of LPCVD-Ti_0.17Al_0.83N and PVD-Ti_1−xAl_xN coatings were compared. The X-ray diffraction (XRD) results and scanning electron microscopy (SEM) images revealed that the LPCVD-Ti_0.17Al_0.83N coating had a face-centered cubic (fcc) structure, while presenting a crack-free surface morphology and a compressive residual stress of −131.9 MPa. The PVD coatings with a composition of x ≤ 0.60 had an fcc structure, while the PVD-Ti_0.33Al_0.67N coating consisted of fcc and w-AlN phases. The results of the electrochemical corrosion test showed that the LPCVD-Ti_0.17Al_0.83N coating had the lowest corrosion current density in a 3.5 wt.% NaCl solution. After a 20-day immersion corrosion test in a 5 mol/L HCl solution, the LPCVD-Ti_0.17Al_0.83N coating displayed higher stability than the PVD-Ti_1−xAl_xN coating. The results of electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) analysis revealed that more uniform and denser passivation film, as well as higher Al₂O₃ proportion in the Al₂O₃/TiO₂ composite passive layer, led to the outstanding corrosion resistance of the LPCVD-Ti_0.17Al_0.83N coating.

Casting infiltration technology was used to fabricate a high-chromium coating on the surface of parent ZG45 steel with different Ni content. SEM, EDS analysis, CALPHAD-type calculations, Rockwell hardness test and impact wear test were utilized to investigate the influence of Ni on the microstructure, hardness and impact wear resistance performance. The as-cast microstructure of the casting infiltration coatings with Ni content less than 2.82 wt.% was a pearlite matrix with reticular eutectic M₇C₃ carbide, while the matrix of the coatings with 5.53 wt.% Ni showed austenite. The content of Ni had little effect on both the solidification behavior and the amount of eutectic M₇C₃. After heat treatment, the transformation of the matrix to martensite occurred, and the Rockwell hardness significantly increased. The proportion of the retained austenite in the casting infiltration coatings increased from 6.4 vol.% to 27.5 vol.% with increasing Ni content, resulting in a decrease in the hardness. Due to a better balance of the hardness and toughness, the casting infiltration coating with 1.53 wt.% Ni showed the best impact wear resistance performance.