This work aimed to fabricate two varieties of near-equiatomic TiNbZr and TiTaZr medium-entropy alloy (MEA) claddings on pure Ti as protective layers by stepwise laser cladding. Their stratified component distribution, microstructural characteristics, and phase constitutions were analyzed, with their hardness and wear resistance were compared with that of pristine Ti. It was found that a single body-centered-cubic solid-solution phase in both MEA claddings were realized on the hexagonal closed-packed pure Ti substrates. The subgrain structures in the TiNbZr cladding were cellular grains, while the ones in the TiTaZr cladding were much denser dendrite arms, which led to increased residual stress. The results showed that the hardness of the TiNbZr and TiTaZr claddings were 450 ± 30 HV0.2 and 513 ± 27 HV0.2, respectively, 2.6 times and 3 times that of the pure Ti (170 ± 11 HV0.2). Also, the consequent wear rates decreased from 2.08 × 10−4 mm3·N−1·m−1 (pure Ti) to 0.49 × 10−4 mm3·N−1·m−1 (TiNbZr) and 0.32 × 10−4 mm3·N−1·m−1 (TiTaZr). Such high hardness and enhanced wear resistance are attributed to the solid-solution strengthening of the body-centered-cubic phase and the residual stress in the claddings. The realization of hard MEA layers by stepwise laser cladding offers a flexible and effective way for protecting pure Ti.

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The crystallizer is the key component controlling the solidification process and is mainly made of pure Cu. The poor wear resistance and oxidation resistance of pure Cu limit the working life of the Cu crystallizer. Herein, Fe/FeCr coatings are designed and successfully fabricated on the Cu substrate by laser cladding technique. The composition, microstructure, mechanical, and thermal properties of the Cu–Fe/FeCr composite are investigated. The coating is composed of a body‐centered cubic Fe–Cr alloy phase. The grains on the surface are equiaxed grains with an average diameter of 2 μm. The coating exhibits a tensile strength 3 times of Cu substrate and well elongation thanks to the fine‐grain structure. The interface between coating and substrate is metallic bonding and possesses a shear strength of as high as 200 MPa. The coating shows obvious advantages in wear resistance and antioxidation at high temperatures in comparison to Cu substrate. The laser cladding Cu–Fe/FeCr composite is promising to prolong crystallizer life for continuous casting.