搭接工艺对选区激光熔化镍基单晶高温合金<strong>DD491</strong>晶体取向与微观组织的影响

搭接工艺对选区激光熔化镍基单晶高温合金DD491晶体取向与微观组织的影响

张振武, 李继康, 许文贺, 沈沐宇, 戚磊一, 郑可盈, 李伟, 魏青松

Effects of Overlapping Process on Grain Orientation and Microstructure of Nickel-Based Single-Crystal Superalloy DD491 Fabricated by Selective Laser Melting

ZHANG Zhenwu, LI Jikang, XU Wenhe, SHEN Muyu, QI Leiyi, ZHENG Keying, LI Wei, WEI Qingsong

图16 扫描间距h影响搭接区晶体生长示意图

Fig.16 Schematics of smaller scanning hatch (a), larger scanning hatch (b), and heat gradient (c) affecting the grain growth in the overlapping region (G₀—residual heat gradient in old melt pool; $G_{i n p u t}$ —heat gradient of laser input; $G_{u v w}$ —heat gradient of crystal solidification; α—the angle between $G_{u v w}$ and [001]-axis; $G_{100}$ , $G_{010}$ , and $G_{001}$ — $G_{u v w}$ component on [100], [010], and [001] direction, respectively; G_∥ and G_⊥—the magnitude of $G_{i n p u t}$ component parallel and perpendicular to [001]-axis)