Controllable in-situ aging during selective laser melting: Stepwise precipitation of multiple strengthening phases in Inconel 718 alloy

• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2019,（9）
• 页码范围: 1925-1930
• 页数: 6页
• 语种: 英文

摘要

A controllable in-situ aging treatment of Inconel 718 alloy was successfully developed by governing the types and times of the thermal cycles during selective laser melting (SLM).The sequential precipitation of γ',composite phase of primary/secondary γ'coated by a γ" shell,and γ" occurs as the times of vertical thermal cycles increase when laser peak temperature (Tp) is between the precipitation temperature of strengthening phase (Tpre) and liquid temperature (TL),which causes an increase in microhardness by 40 HV.Also,short-term aging mechanisms on three types of strengthening phases are proposed based on a great number of vacancies in the matrix.