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RISS 인기검색어
- 검색키워드
- 저자 : Octavio Pereira (검색결과 3 건)
- 무료
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Simulation of Cryo-cooling to Improve Super Alloys Cutting Tools
Octavio Pereira,Adrián Rodríguez,Amaia Calleja-Ochoa,Ainhoa Celaya,Luis Norberto López de Lacalle,Asier Fernández-Valdivielso,Haizea González 한국정밀공학회 2022 International Journal of Precision Engineering and Vol.9 No.1
Improve machining processes from an environmental point of view is a hot topic currently. In this line, cryogenics CO 2 is presented as a solution to substitute conventional oil emulsions. However, to be applied industrially, it is needed to control CO 2 flow rate with the aim of reducing CO 2 consumption to reach what it is known as ECO 2 -performance (economy + ecology). Then, despite currently CO 2 cooling technique is used as external coolant, it is needed to improve its use—especially in milling processes—for achieving this goal. In line with this, in this paper is presented the use of CO 2 as tool internal coolant as a solution to optimize its use. For checking its suitability, a study based on computer fluid dynamics with a new cryogenic tool channels design and experimental tests were carried out for analyzing the differences between using CO 2 as internal and external coolant with the aim of improving the use of cryogenic gases during Inconel 718 milling processes. The results show that the use of CO 2 as internal coolant improves the current milling process not only from environmental point of view but also economic and technical, bringing CO 2 cryogenic technology closer to industrial milling conditions.
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Nozzle Design for Combined Use of MQL and Cryogenic Gas in Machining
Octavio Pereira,Adrián Rodríguez,Joaquín Barreiro,Ana Isabel Fernández-Abia,Luis Norberto López de Lacalle 한국정밀공학회 2017 International Journal of Precision Engineering and Vol.4 No.1
Nowadays, the need for not only technically but also environmentally efficient machining processes is increasing. In this context, the reduction of oil emulsion type coolants used during machining of aeronautical engine components supposes a great challenge. In this paper, a novel approach based on the design, optimization and validation of a nozzle adaptor combining cryogenic technology and minimum quantity lubrication systems is proposed. The proposed work also deals with the aim of obtaining a cost-effective process. Thus, CO2 flow and velocity was optimized in this line. Theoretically-based analysis were performed and compared with computational fluid dynamics (CFD) simulations and with real experimental tests as well. Once optimizing these key factors, two nozzle adaptors were designed and simulated by CFD. Different geometries were tested looking for the most efficient design. Finally, to obtain a feasible industrial product, the developed nozzle was tested as a CryoMQL demonstrator comparing with other lubri-coolant techniques during milling Inconel 718. Results show a successful balance between technical and environmental issues using this technology when milling aeronautical alloys.
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A Cleaner Milling Process Replacing Emulsion Coolant by Cryogenics CO2
Octavio M. Pereira Neto,Calleja‑Ochoa,I. Ayesta,A. Rodríguez,H. González‑Barrio,L. N. López de Lacalle 한국정밀공학회 2024 International Journal of Precision Engineering and Vol.11 No.1
In manufacturing sector, looking for a balance between environmental and technical efficiency taking into account productivity is mandatory. Some sectors, such as the biomedical manufacturing sector, also needs to consider the cleanness inherent to prosthesis manufacturing processes for avoiding pathogens transfer to the human body, that is, neither chemicals, bacteria, nor uncontrolled metals can be introduced during the surgical intervention. This work here presented stems from the idea of analyzing the cleanness of cryogenic cooling to be applied to medical pieces. For this, several samples were machined using CO2 cryogenic technology and oil emulsions, respectively. In particular, a modified milling tool was used to apply not only efficiently as cutting fluid but also as cleaner fluid. Afterwards, they were analyzed by Scanning Electron Microscope (SEM) with the aim of looking for biological remains. Finally, with the aim of validating the modified tool in which CO2 is introduced axially as internal coolant, its tool life was tested in comparison with a conventional one. The results shown that the use of CO2 as internal coolant significantly improves the cleanness of current machining processes in comparison with the use of oil emulsions and the way in which is injected does not affect to machining performance.
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