【摘要】 激光粉末床熔融(laser powder bed fusion, LPBF)被广泛应用于航空航天领域的镍基高温合金零部件制造，而组织高度依赖于LPBF的工艺参数，通过改变热输入研究LPBF制备IN738LC的组织及显微硬度调控能力.结果表明，试验中的IN738LC合金工艺性较好，在40～97 J/mm~3体能量密度(volume energy density,VED)范围内无裂纹、孔洞缺陷；晶粒尺寸随热输入增加而增大，从44 J/mm~3的百微米级提高到94 J/mm~3的毫米级.侧截面(xOz面)的显微硬度略高于水平截面(xOy面)显微硬度，且随体能量密度从38 J/mm~3提高到91 J/mm~3侧截面的显微硬度从340 HV1.0提高到440 HV1.0，而水平截面显微硬度从330 HV1.0提高到420 HV1.0.更多还原

【Abstract】 LPBF is widely used in the manufacture of nickel-based superalloy parts in aerospace industry. The microstructure which determines mechanical properties of parts is dependent on LPBF process parameters. In this work, the tailored ability of the microstructure and microhardness for LPBF built IN738LC was studied by altering heat input. The results show that the IN738LC alloy has a good printability and no crack or hole defects in the VED range of 40 J/mm~3 to 97 J/mm~3. The grain size increased with the heat input from a 100-micron scale of 44 J/mm~3 to a millimeter scale of 94 J/mm~3. The microhardness of xz plane was slightly higher than that of x Oy plane. Moreover, microhardness was increased from 340 HV1.0 to 440 HV1.0 and from 330 HV1.0 to 420HV1.0 for x Oz plane and xy plane with increase of VED from 38 J/mm~3 to 91 J/mm~3.更多还原