拉伸变形对高熵合金激光涂层组织和性能的影响

Effect of tensile deformation on the microstructure and properties of highentropy alloy laser cladding coating

采用激光熔覆设备在不锈钢片和40Cr钢表面制得Al2Co Cr Cu0.5Fe Mo Ni Ti高熵合金涂层,对涂层进行退火和拉伸变形,并采用X射线衍射仪、扫描电子显微镜和显微硬度计对涂层进行测试。结果表明,熔覆涂层经过抛光和王水腐蚀后,显微形貌为胞粒状特征。300℃退火对涂层硬度没有影响;500~700℃退火后,涂层硬度提高,说明涂层具有时效硬化效应。涂覆态涂层由bcc单相组成,300℃退火后,涂层保持稳定的相结构。拉伸变形后,涂层的衍射峰强度增加,晶界清晰;硬度则随变形量增加先降低后提高。涂层具有良好的附着性能,除了断口附近出现涂层脱落外,其他位置的涂层都保持良好的附着状态。

Al2CoCrCu0.5FeMoNiTi high-entropy alloy laser cladding coating was synthesized on stainless steel and40 Cr steel with laser cladding equipment. The coating was annealed and stretched,and was tested by X-ray diffractometer,scanning electron microscope and microhardness tester. Results show that the coating shows granular structure after polishing and aqua regia corrosion. The hardness of the coating is not affected by annealing at300 ℃,while the hardness of the coating increases after annealing at 500-700 ℃,indicating that the coating has an aging effect. The cladding coating is composed of bcc single phase,and the coating maintains a stable phase structure after annealing at 300 ℃. After tensile deformation,the diffraction peak intensity of the coating increases and the grain boundary is clear. The hardness decreases firstly and then increases with the increase of deformation.The coating has good adhesion,except that the coating near the fracture surface is peeling.