Surface polishes of the SKD 61 tool steel by a femto pulse laser operating in a wide range of powers

Chang Shuo Chang, Chen Kuei Chung, Jen Fin Lin

研究成果: Article

1 引文 斯高帕斯(Scopus)

摘要

SKD 61 tool steel workpieces without prior heat treatment are adopted for pulse femto laser polish with the power in a range of 0.1–20 mW. Single-pass tracks are provided first to evaluate the width (W) and depth (D) of groove's lateral profile. With the characteristics exhibited in the nearly constant D/W data and the noticeable changes in the crystal species and the Fe content in this powers range, the three power subregions and the powers required for the solid-(plasma) ablation and the ablation-evaporation plus plasma breakdown transitions can be identified clearly. Surfaces polished with 0, 50, and 70 % as the overlap ratio are presented to investigate the mean areal roughness (Sa) and the highest roughness amplitude (HA) affected by the laser fluence (F) in these three subregions and the overlap ratio. As power is applied below the solid-ablation transition (9–10 mW, F: 1.3777–1.5239 J/cm2), (Sa)0% >> (Sa)70 % > (Sa)50% is obtained; if it is applied higher than this transition, (Sa)0% >> (Sa)50 % > (Sa)70% is presented. When the power is applied beyond the threshold (14 mW, 1.7224 J/cm2) for material evaporation and plasma breakdown, the HA value is reduced by increasing overlap ratio. As the laser power is sufficient low (<5 mW, F: 0.8252 J/cm2), the hardness (HD) and reduced modulus (Er) of polished surface are dominated by areal surface roughness (Sa), they are lowered by increasing in Sa.

原文English
文章編號116465
期刊Journal of Materials Processing Technology
277
DOIs
出版狀態Published - 2020 三月

    指紋

All Science Journal Classification (ASJC) codes

  • Ceramics and Composites
  • Computer Science Applications
  • Metals and Alloys
  • Industrial and Manufacturing Engineering

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