【摘要】 采用料浆烧结工艺在激光选区熔化成形Ta10W合金基体表面制备三层结构的钼-硅系高温抗氧化涂层，采用SEM和EDS表征合金基体及涂层的微观组织和元素分布，评价合金基体及涂层的拉伸性能、显微硬度和涂层结合强度。结果表明：激光选区熔化成形Ta10W合金表面涂层具有外层、次外层和内层三层结构，外层为TaSi₂和MoSi₂相，次外层为TaSi₂相和弥散分布的Ta₅Si₃相，内层为Ta₅Si₃相。涂层试样和去除涂层试样的屈服强度、抗拉强度和均匀伸长率分别为639、647 MPa、13.6%和602、675 MPa、22.7%。相比Ta10W合金基体试样，去除涂层试样的均匀伸长率增加了5.5%，其原因是涂层制备过程中的热作用消除了激光选区熔化成形Ta10W合金的残余应力。涂层试样的屈服强度增加了37 MPa，其原因是涂层的制备提高了屈服强度。涂层外层、次外层、内层和基体的硬度分别为550HV_0.2、1120HV_0.2、534HV_0.01和307HV_0.2。涂层平均结合强度高达63 MPa，远高于目前结合强度优异的陶瓷系和高熵合金系涂层。这是因为本研究中三层结构的钼-硅系高温抗氧化涂层与基体产生较好的冶金结合。更多还原

【Abstract】 The three-layer structure molybdenum-silicon high-temperature oxidation-resistant coating was prepared on selective laser melting Ta10W alloy by slurry sintering process.The microstructure and element distribution of the Ta10W alloy and coating were characterized by SEM and EDS.The tensile properties,microhardness of the Ta10W alloy and coating,and the coating bonding strength were tested.The results show that the coating of selective laser melting Ta10W alloy is divided into three layers:outer,sub-outer and inner layers.The outer layer is TaSi₂ and MoSi₂ phases,the sub-outer layer is TaSi₂ phase and dispersed Ta₅Si phase,and the inner layer is Ta₅Si₃ phase.The yield strength,tensile strength and uniform elongation of the coating and remove coating specimens are 639,647 MPa,13.6%,and 602 MPa,675 MPa,22.7%,respectively.Compared to the Ta10W alloy specimen,the uniform strain of the remove coating specimen is increased by 5.5%.The reason for this is that the thermal effect in the coating preparation process eliminates the residual stress of the Ta10W alloy formed by selective laser melting.The yield strength of the coated specimen is increased by 37 MPa due to the application of the coating.The microhardness of the outer layer,sub-outer layer,inner layer and Ta10W alloy were 550HV_0.2,1120HV_0.2,534HV_0.01 and 307HV_0.2,respectively.The average coating bonding strength is 63 MPa,which is higher than that of the ceramic and high entropy alloy coatings.This is due to the fact that the threelayer coating has a good metallurgical bond to the Ta10W alloy.更多还原