An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy
The conventional (mechanical) micro-drilling of Inconel 625 alloys suffers from premature breakage of the drill bit due to its brittle nature and limited cutting tool life. Even greater problems are encountered when micro-drilling holes at an acute angle to the machining plane. In such a process, th...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Lubricants |
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| Online Access: | https://www.mdpi.com/2075-4442/11/9/384 |
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| author | Krzysztof Szwajka Joanna Zielińska-Szwajka Krzysztof Żaba Tomasz Trzepieciński |
| author_facet | Krzysztof Szwajka Joanna Zielińska-Szwajka Krzysztof Żaba Tomasz Trzepieciński |
| author_sort | Krzysztof Szwajka |
| collection | DOAJ |
| description | The conventional (mechanical) micro-drilling of Inconel 625 alloys suffers from premature breakage of the drill bit due to its brittle nature and limited cutting tool life. Even greater problems are encountered when micro-drilling holes at an acute angle to the machining plane. In such a process, there are great difficulties associated with the low stiffness of the tool, which leads to the frequent breakage of the drill during machining. Therefore, in this type of mechanical drilling operation, the hole surface is usually milled with an end mill to provide a flat surface on the entry side of the drill bit. The aim of this article is to recognise the process of sequential micro-drilling and to assess the possibility of its use as an effective and efficient method of micro-drilling in hard-to-cut metals. The paper describes the process of initial laser drilling followed by final mechanical micro-drilling. Inconel 625 Ni-based alloy sheets were used as the test material. The shape and microstructure of pre-holes made with a laser, the volumetric efficiency of laser processing, the energy in the mechanical drilling process, and tool wear were analysed. The research results show that in the sequential drilling process, mechanical re-drilling eliminates the geometrical discrepancies resulting from the laser pre-drilling. In addition, it was found that, compared to mechanical micro-drilling, the use of sequential micro-drilling resulted in a two-fold increase in drill life. It has been also observed that sequential machining reduces the energy demand by 60% compared to mechanical micro-drilling. In addition, it was found that the edge of the drill bit is a key factor in deciding the target diameter of the laser-drilled pilot hole, and thus in selecting the micro-drilling parameters. |
| first_indexed | 2024-03-10T22:31:58Z |
| format | Article |
| id | doaj.art-589cf897cb80440ebb259f19f426f6b7 |
| institution | Directory Open Access Journal |
| issn | 2075-4442 |
| language | English |
| last_indexed | 2024-03-10T22:31:58Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Lubricants |
| spelling | doaj.art-589cf897cb80440ebb259f19f426f6b72023-11-19T11:39:44ZengMDPI AGLubricants2075-44422023-09-0111938410.3390/lubricants11090384An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based AlloyKrzysztof Szwajka0Joanna Zielińska-Szwajka1Krzysztof Żaba2Tomasz Trzepieciński3Department of Integrated Design and Tribology Systems, Faculty of Mechanics and Technology, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, PolandDepartment of Component Manufacturing and Production Organization, Faculty of Mechanics and Technology, Rzeszow University of Technology, ul. Kwiatkowskiego 4, 37-450 Stalowa Wola, PolandFaculty of Non-Ferrous Metals, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Krakow, PolandDepartment of Manufacturing Processes and Production Engineering, Rzeszow University of Technology, al. Powstańców Warszawy 8, 35-959 Rzeszow, PolandThe conventional (mechanical) micro-drilling of Inconel 625 alloys suffers from premature breakage of the drill bit due to its brittle nature and limited cutting tool life. Even greater problems are encountered when micro-drilling holes at an acute angle to the machining plane. In such a process, there are great difficulties associated with the low stiffness of the tool, which leads to the frequent breakage of the drill during machining. Therefore, in this type of mechanical drilling operation, the hole surface is usually milled with an end mill to provide a flat surface on the entry side of the drill bit. The aim of this article is to recognise the process of sequential micro-drilling and to assess the possibility of its use as an effective and efficient method of micro-drilling in hard-to-cut metals. The paper describes the process of initial laser drilling followed by final mechanical micro-drilling. Inconel 625 Ni-based alloy sheets were used as the test material. The shape and microstructure of pre-holes made with a laser, the volumetric efficiency of laser processing, the energy in the mechanical drilling process, and tool wear were analysed. The research results show that in the sequential drilling process, mechanical re-drilling eliminates the geometrical discrepancies resulting from the laser pre-drilling. In addition, it was found that, compared to mechanical micro-drilling, the use of sequential micro-drilling resulted in a two-fold increase in drill life. It has been also observed that sequential machining reduces the energy demand by 60% compared to mechanical micro-drilling. In addition, it was found that the edge of the drill bit is a key factor in deciding the target diameter of the laser-drilled pilot hole, and thus in selecting the micro-drilling parameters.https://www.mdpi.com/2075-4442/11/9/384angled holesdrillingInconel 625laser drillingre-drillingthrust force |
| spellingShingle | Krzysztof Szwajka Joanna Zielińska-Szwajka Krzysztof Żaba Tomasz Trzepieciński An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy Lubricants angled holes drilling Inconel 625 laser drilling re-drilling thrust force |
| title | An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy |
| title_full | An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy |
| title_fullStr | An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy |
| title_full_unstemmed | An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy |
| title_short | An Investigation of the Sequential Micro-Laser Drilling and Conventional Re-Drilling of Angled Holes in an Inconel 625 Ni-Based Alloy |
| title_sort | investigation of the sequential micro laser drilling and conventional re drilling of angled holes in an inconel 625 ni based alloy |
| topic | angled holes drilling Inconel 625 laser drilling re-drilling thrust force |
| url | https://www.mdpi.com/2075-4442/11/9/384 |
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