本发明属于难熔高熵合金涂层技术领域,公开了一种具有梯度结构的难熔高熵合金涂层及其制备方法。所述制备方法为：除去表面的氧化膜和杂质,获得预处理后的基体；采用激光熔覆技术,在惰性气氛下,将沉积涂层材料成分表达式为W-aMo-bTa-cM-d的难熔高熵合金粉末以同步式送粉的方式,沉积于所述预处理后的基体的表面,以在预处理后的基体表面上形成熔覆层；对熔覆层表面进行激光重熔,以使所述熔覆层转化为具有梯度结构的难熔高熵合金涂层。本发明通过低能量密度的同步式送粉激光熔覆+激光重熔能在涂层外表面实现单相固溶体结构,同时实现了从强度、硬度到热膨胀系数均匀过渡的梯度涂层的制备,获得具有优异性能的涂层材料。

The invention belongs to the technical field of refractory high entropy alloy coating and discloses a refractory high entropy alloy coating with gradient structure and a preparation method thereof. The preparation method is as follows: removing the oxide film and impurities on the surface to obtain the pretreated matrix; By laser cladding technology, the refractory high entropy alloy powder with the composition expression W-aMo-bTa-cM-d is deposited on the surface of the pretreated matrix by synchronous powder feeding under an inert atmosphere, so as to form a cladding layer on the surface of the pretreated matrix. Laser remelting is performed on the surface of the cladding layer to transform the cladding layer into a refractory high entropy alloy coating with a gradient structure. The invention realizes a single-phase solid solution structure on the outer surface of the coating by means of low energy density synchronous powder feeding laser cladding + laser remelting energy, and at the same time realizes the preparation of a gradient coating with uniform transition from strength, hardness to thermal expansion coefficient, and obtains a coating material with excellent performance.