Scholarlink

<p>This study explores the fabrication of square thin-wall structures using Laser powder-directed energy deposition (LP-DED) with a 0.8&#xa0;mm laser spot size on Inconel 718, targeting applications like micro-channel heat exchangers. Material accumulation at corners, due to nozzle deceleration and acceleration, presents a major challenge in DED. To address this, two scanning strategies were compared: a conventional path and a novel U-path approach. The U-path, along with optimized parameters, enabled fabrication of high-quality structures featuring sharp corners, uniform wall thickness below 0.7&#xa0;mm, and no defects such as earing and tearing, The effects of laser power, scan speed, powder flow rate, and corner geometry (2, 1 and sharp) were evaluated in terms of dimensional accuracy, surface characteristics, microstructure, and microhardness. Multiple linear regression analysis revealed that while corner geometry had no significant effect on wall thickness, it strongly influenced surface roughness. Optimal results included a minimum wall thickness of 0.646 mm, surface roughness (Sa) of 8.01 µm, waviness (Wz-v = 56.007&#xa0;µm, Wz-h = 47.833&#xa0;µm), and a peak microhardness of 286.12 ± 9.10&#xa0;HV. Surface roughness was reduced by 71%, demonstrating substantial improvement. The optimal fabrication parameters identified were a laser power of 300&#xa0;W, scan speeds of 1500–2000 mm/min, a powder feed rate of 4 g/min, and a 2 mm corner radius. The findings demonstrate that the U-path scanning strategy effectively minimizes material accumulation at corners, enabling smoother directional transitions and enhanced geometric accuracy compared to conventional sharp-corner paths</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Minimizing surface roughness and material accumulation in thin-walled square structures via laser powder-DED

  • 期刊论文

  • 发表日期：

    2025年7月31日

查看全文
  • Seyedali Momeni,
  • Guilherme Rosati Mecelis,
  • Renato Goulart Jasinevicius

摘要

This study explores the fabrication of square thin-wall structures using Laser powder-directed energy deposition (LP-DED) with a 0.8 mm laser spot size on Inconel 718, targeting applications like micro-channel heat exchangers. Material accumulation at corners, due to nozzle deceleration and acceleration, presents a major challenge in DED. To address this, two scanning strategies were compared: a conventional path and a novel U-path approach. The U-path, along with optimized parameters, enabled fabrication of high-quality structures featuring sharp corners, uniform wall thickness below 0.7 mm, and no defects such as earing and tearing, The effects of laser power, scan speed, powder flow rate, and corner geometry (2, 1 and sharp) were evaluated in terms of dimensional accuracy, surface characteristics, microstructure, and microhardness. Multiple linear regression analysis revealed that while corner geometry had no significant effect on wall thickness, it strongly influenced surface roughness. Optimal results included a minimum wall thickness of 0.646 mm, surface roughness (Sa) of 8.01 µm, waviness (Wz-v = 56.007 µm, Wz-h = 47.833 µm), and a peak microhardness of 286.12 ± 9.10 HV. Surface roughness was reduced by 71%, demonstrating substantial improvement. The optimal fabrication parameters identified were a laser power of 300 W, scan speeds of 1500–2000 mm/min, a powder feed rate of 4 g/min, and a 2 mm corner radius. The findings demonstrate that the U-path scanning strategy effectively minimizes material accumulation at corners, enabling smoother directional transitions and enhanced geometric accuracy compared to conventional sharp-corner paths