The IN718 alloys with different Al contents were fabricated by laser deposition manufacturing (LDM) technology. The microstructure and tensile properties of LDMed IN718 alloy with different Al contents before and after homogenization-solution-double aging (HSA) treatment were analyzed. The as-deposited samples show dendrite structure which develops with the addition of Al element. The microstructure of the as-deposited samples mainly consists of the γ matrix, Laves phases and a small amount of carbides. The HSA treatment improves the precipitation of γ″, γ′ and δ strengthening phases, and with the Al content increasing, the γ′ phase increases, but the γ″ phase decreases. With the increasing of Al content, the tensile strength of as-deposited samples increases, but the elongation decreases. For HSA-treated samples, the IN718+0.5Al alloy shows the highest tensile strength and elongation. The tensile fracture surfaces of LDMed IN718 alloys show dimpled surfaces, indicating the transgranular ductile failure mode.

中文翻译：

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Al添加对激光沉积制造IN718合金显微组织和力学性能的影响

采用激光沉积制造（LDM）技术制备了不同Al含量的IN718合金。分析了不同Al含量LDMed IN718合金均匀化-固溶-二次时效（HSA）处理前后的显微组织和拉伸性能。沉积态样品显示出随着 Al 元素的添加而形成的枝晶结构。沉积态样品的显微组织主要由γ基体、Laves相和少量碳化物。 HSA处理改善了沉淀γ”，γ' 和δ强化相，并且随着Al含量的增加，γ′ 相位增加，但γ”相减少。随着Al含量的增加，沉积态样品的抗拉强度增加，但延伸率降低。对于 HSA 处理的样品，IN718+0.5Al 合金表现出最高的拉伸强度和伸长率。 LDMed IN718 合金的拉伸断口表面呈现凹坑表面，表明穿晶延性破坏模式。