采用激光增材制造技术制备了钴基高温合金DZ40M, 研究了沉积态DZ40M的微观组织, 对比分析了不同热处理制度下DZ40M的微观组织及力学性能。结果表明, 激光增材制造技术得到的DZ40M组织比传统定向凝固的更细, 拉伸强度及塑性都有不同程度的增大。1280 ℃固溶处理能够使DZ40M的初生碳化物充分固溶并析出新的共晶组织, 再经950 ℃或者1020 ℃的时效处理, 有二次碳化物析出, 时效处理对DZ40M力学性能起到良好的强化作用, 并在一定范围内保留其塑性, 其中1280 ℃/4 h＋1020 ℃/12 h热处理制度处理试样, 能够在提高室温抗拉强度的同时, 最大程度地保留沉积态塑性。

Cobalt-based superalloy DZ40M sample is prepared by laser additive manufacturing method and its microstructure is studied. The microstructure and mechanical properties of the alloy under different heat treatments are compared. Results show that the dendrites size of DZ40M microstructure obtained by the laser additive manufacturing method is finer than the traditional directional solidification structure, and the tensile strength and plasticity are improved in different degrees. Solution treatment under 1280 ℃ can make the primary carbide achieve full solid solution and new eutectic structure appears. Then after 950 ℃ or 1020 ℃ aging treatment, the secondary carbides are obtained. The samples after aging treatment show better mechanical properties. Especially, 1280 ℃/4 h+1020 ℃/12 h heat treatment system can improve the tensile strength at room temperature and keep the maximum degree of ductility of the deposition state sample.