Advanced ceramics are increasingly applied in optical, electronic, mechanical and biomedical applications thanks to their inherent physical properties such as electrical behavior, electromagnetic response, high temperature strength, hardness and corrosion resistance. Nevertheless, this kind of materials are usually very difficult-to-machine by conventional technologies, while their applications become more and more demanding in terms of quality and precision. In such scenario, the Fine Abrasive Water Jet (FAWJ) represents a very appealing and promising technology compared to micromachining, laser or EDM, offering many advantages such as the absence of thermal distortions, high flexibility and versatility, small cutting forces and the increasing capability to cut smaller and smaller features. In the present work, carried out at Tecnalia R&I in collaboration with Politecnico di Milano, the machining of thin sheets of piezoelectric material (lead titanate zirconate, also called PZT) is investigated with a DOE approach, in order to optimize the FAWJ system cutting parameters, to test its capability and to demonstrate that it is a concrete alternative to high-precision machine ceramic materials. Finally, a possible application of PZT as actuator for micro positioning is presented.
I materiali ceramici piezoelettrici rappresentano un interessante campo di ricerca nel campo dell’ottica, dell’elettronica, per applicazioni meccaniche e biomediche grazie alle loro proprietà elettriche e magnetiche, alla resistenza alle alte temperature, alla durezza superficiale e alla resistenza alla corrosione. Tuttavia, questi materiali non possono essere lavorati con le tecnologie convenzionali: il fine abrasive water jet (FAWJ) rappresenta più che un valido concorrente di tecnologie come il laser o l’electric discharge machining (EDM) per via dell’assenza di zone termicamente alterate, piccole forze di taglio e una grande flessibilità. Il lavoro, sviluppato presso Tecnalia R&I, un centro di ricerca a San Sebastian (Spagna), in collaborazione con il Politecnico di Milano, consiste nella lavorazione di sottili piastrine di materiale ceramico piezoelettrico (titanato zirconato di piombo, PZT). Una prima ottimizzazione dei parametri è stata effettuata con un approccio statistico (DOE, design of experiments), per dimostrare tecnicamente la possibilità di lavorare questo materiale con buoni risultati dal punto di vista della precisione dimensionale e della rugosità. Un attuatore a due gradi di libertà, sviluppato dall’Università di Pisa, viene infine presentato come possibile applicazione industriale.
Fine abrasive water jet machining of piezoelectric ceramics
TROLLI, ALESSANDRO
2010/2011
Abstract
Advanced ceramics are increasingly applied in optical, electronic, mechanical and biomedical applications thanks to their inherent physical properties such as electrical behavior, electromagnetic response, high temperature strength, hardness and corrosion resistance. Nevertheless, this kind of materials are usually very difficult-to-machine by conventional technologies, while their applications become more and more demanding in terms of quality and precision. In such scenario, the Fine Abrasive Water Jet (FAWJ) represents a very appealing and promising technology compared to micromachining, laser or EDM, offering many advantages such as the absence of thermal distortions, high flexibility and versatility, small cutting forces and the increasing capability to cut smaller and smaller features. In the present work, carried out at Tecnalia R&I in collaboration with Politecnico di Milano, the machining of thin sheets of piezoelectric material (lead titanate zirconate, also called PZT) is investigated with a DOE approach, in order to optimize the FAWJ system cutting parameters, to test its capability and to demonstrate that it is a concrete alternative to high-precision machine ceramic materials. Finally, a possible application of PZT as actuator for micro positioning is presented.File | Dimensione | Formato | |
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2012_04_Trolli.pdf
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https://hdl.handle.net/10589/43581