激光粉末床熔融镍基高温合金中第二相演化机制与调控策略进展

彭望君, 王长河, 杜大帆, 董安平, 陈彪, 孙宝德

A Review on the Evolution Mechanisms and Regulation Strategies of Secondary Phases in Laser Powder Bed Fusion Nickel-Based Superalloys

PENG Wangjun, WANG Changhe, DU Dafan, DONG Anping, CHEN Biao, SUN Baode

表1 LPBF镍基高温合金的缺陷类型、成因及化学不均匀性(元素偏析)

Table 1 Defect types, causes, and chemical inhomogeneity (element segregation) in nickel-based superalloys by LPBF

Defect type Characteristic size Main cause Impact on secondary phase Porosity 20-200 μm Entrapment of protective gas / keyhole collapse Localized accumulation of γ′ Hot cracking Length 500 μm Shrinkage stress of the liquid film Blocking the distribution of carbides Element segregation Segregation bandwidth 50 μm Solute trapping between dendrites Promoting coarsening of γ″