A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications
The mechanisms of deep-hole microdrilling of pure Mg material were experimentally studied in order to find a suitable setup for a novel intraocular drug delivery device prototyping. Microdrilling tests were performed with 0.20 mm and 0.35 mm microdrills, using a full factorial design in which cuttin...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-01-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/14/1/132 |
| _version_ | 1797438611244711936 |
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| author | Margherita Pizzi Francesco De Gaetano Marco Ferroni Federica Boschetti Massimiliano Annoni |
| author_facet | Margherita Pizzi Francesco De Gaetano Marco Ferroni Federica Boschetti Massimiliano Annoni |
| author_sort | Margherita Pizzi |
| collection | DOAJ |
| description | The mechanisms of deep-hole microdrilling of pure Mg material were experimentally studied in order to find a suitable setup for a novel intraocular drug delivery device prototyping. Microdrilling tests were performed with 0.20 mm and 0.35 mm microdrills, using a full factorial design in which cutting speed <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>v</mi><mi>c</mi></msub></semantics></math></inline-formula> and feed <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula> were varied over two levels. In a preliminary phase, the chip shape was evaluated for low feeds per tooth down to 1 μm, to verify that the chosen parameters were appropriate for machining. Subsequently, microdrilling experiments were carried out, in which diameter, burr height and surface roughness of the drilled holes were examined. The results showed that the burr height is not uniform along the circumference of the holes. In particular, the maximum burr height increases with higher cutting speed, due to the thermal effect that plasticizes Mg. Hole entrance diameters are larger than the nominal tool diameters due to tool runout, and their values are higher for high <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>v</mi><mi>c</mi></msub></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula>. In addition, the roughness of the inner surface of the holes increases as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula> increases. |
| first_indexed | 2024-03-09T11:40:33Z |
| format | Article |
| id | doaj.art-bb629ed3683c4b36a4e5e05a668d5abb |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T11:40:33Z |
| publishDate | 2023-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-bb629ed3683c4b36a4e5e05a668d5abb2023-11-30T23:33:39ZengMDPI AGMicromachines2072-666X2023-01-0114113210.3390/mi14010132A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical ApplicationsMargherita Pizzi0Francesco De Gaetano1Marco Ferroni2Federica Boschetti3Massimiliano Annoni4Department of Mechanical Engineering, Politecnico di Milano, 20156 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, 20133 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, 20133 Milan, ItalyDepartment of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, 20133 Milan, ItalyDepartment of Mechanical Engineering, Politecnico di Milano, 20156 Milan, ItalyThe mechanisms of deep-hole microdrilling of pure Mg material were experimentally studied in order to find a suitable setup for a novel intraocular drug delivery device prototyping. Microdrilling tests were performed with 0.20 mm and 0.35 mm microdrills, using a full factorial design in which cutting speed <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>v</mi><mi>c</mi></msub></semantics></math></inline-formula> and feed <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula> were varied over two levels. In a preliminary phase, the chip shape was evaluated for low feeds per tooth down to 1 μm, to verify that the chosen parameters were appropriate for machining. Subsequently, microdrilling experiments were carried out, in which diameter, burr height and surface roughness of the drilled holes were examined. The results showed that the burr height is not uniform along the circumference of the holes. In particular, the maximum burr height increases with higher cutting speed, due to the thermal effect that plasticizes Mg. Hole entrance diameters are larger than the nominal tool diameters due to tool runout, and their values are higher for high <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>v</mi><mi>c</mi></msub></semantics></math></inline-formula> and <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula>. In addition, the roughness of the inner surface of the holes increases as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mi>f</mi><mi>z</mi></msub></semantics></math></inline-formula> increases.https://www.mdpi.com/2072-666X/14/1/132microdrillingmagnesiummicroholesmicromachinabilityholes qualitychip formation |
| spellingShingle | Margherita Pizzi Francesco De Gaetano Marco Ferroni Federica Boschetti Massimiliano Annoni A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications Micromachines microdrilling magnesium microholes micromachinability holes quality chip formation |
| title | A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications |
| title_full | A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications |
| title_fullStr | A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications |
| title_full_unstemmed | A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications |
| title_short | A Deep-Hole Microdrilling Study of Pure Magnesium for Biomedical Applications |
| title_sort | deep hole microdrilling study of pure magnesium for biomedical applications |
| topic | microdrilling magnesium microholes micromachinability holes quality chip formation |
| url | https://www.mdpi.com/2072-666X/14/1/132 |
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