为制备适用于热喷涂的高熵合金粉末，本工作以金属单质粉末为原料，通过机械合金化(MA)法制备出AlCrCu_0.5Mo_0.5Ni高熵合金粉末。研究了球磨时间对MA粉末相结构、晶粒尺寸和微观组织演变的影响。利用XRD对MA粉末进行了物相分析，并计算了MA粉末的晶粒尺寸、晶格应变和晶格常数。利用SEM和TEM对MA粉末进行了组织形貌和微观结构分析。此外，利用真空等温退火对MA粉末进行相调控。结果表明，AlCrCu_0.5Mo_0.5Ni高熵合金粉末中形成2个bcc固溶体相(bcc1、bcc2)和fcc固溶体相。随着球磨时间的延长，MA粉末发生塑性变形，导致MA粉末的晶粒尺寸减小，晶格应变增大。粉末颗粒的破碎和元素富集区的细化加速了元素的扩散和合金化。球磨至40 h时，粉末颗粒内部元素分布较均匀，bcc1、bcc2和fcc相的质量分数分别为41%、37%和22%，平均粒径(D₅₀)为24 μm，适宜用作热喷涂粉末。球磨40 h的MA粉末经800 ℃退火后，bcc2固溶体结构分解，退火温度达到1000 ℃时，bcc2固溶体完全分解，bcc1和fcc相质量分数分别为68%和21%，并生成11%的CrMo相。随着退火温度升高，MA粉末释放出大量的应变能，导致晶粒尺寸增加，晶格应变减小。当退火温度为800 ℃时，MA粉末硬度和Young's模量最大，分别为(6.54 ± 0.58)和(65.62 ± 3.07) GPa。

Boiler steel is prone to thermal corrosion and abrasion in high-temperature environments, making thermal spray protective coatings a vital solution for enhancing the corrosion and abrasion resistance of boilers. This study focuses on the development of a novel AlCrCu_0.5Mo_0.5Ni high-entropy alloy powder synthesized through mechanical alloying (MA) using monolithic metal powders as starting materials. The effects of milling time on the phase structure, grain size, and microstructure evolution of the MA powder were investigated. Phase characterization was performed using XRD; grain size, lattice strain, and lattice constant were measured; morphological and microstructural analyses were performed using SEM and TEM. Phase regulation through vacuum isothermal annealing techniques was also explored. The findings indicated the formation of two bcc (bcc1, bcc2) and one fcc solid solution phases within the high-entropy alloy powder. With increased milling time, the MA powder experienced plastic deformation, which led to a reduction in grain size and an augmentation of lattice strain. Powder particle fragmentation and refinement of the element-enriched zones facilitated enhanced diffusion and alloying of the elements. At 40 h of milling, the powder particles exhibited a more homogeneous elemental distribution, with phase contents of 41% bcc1, 37% bcc2, and 22% fcc, and an average particle size of 24 μm, making them suitable for thermal spray applications. Annealing at 800 ^oC led to the decomposition of the bcc2 solid solution structure after 40 h of ball milling. Upon increasing the annealing temperature to 1000 ^oC, complete decomposition of the bcc2 solid solution was observed, resulting in 68% bcc1 and 21% fcc phases, with the emergence of 11% CrMo phase. As the annealing temperature was increased, the MA powder released significant strain energy, increasing grain size and a reduction in lattice strain. The maximum hardness and elasticity modulus were achieved after annealing at 800 ^oC, recorded at (6.54 ± 0.58) and (65.62 ± 3.07) GPa, respectively.