GIAMPAOLO CAMPANA | Università di Bologna (original) (raw)

Papers by GIAMPAOLO CAMPANA

Il progetto di ricerca TILAS (Tecnologie Industriali di LAvorazione Schiume metalliche) intende c... more Il progetto di ricerca TILAS (Tecnologie Industriali di LAvorazione Schiume metalliche) intende contribuire alla maggiore conoscenza dei materiali cellulari nelle applicazioni industriali. Le schiume metalliche costituiscono una interessante alternativa ai materiali compositi nella realizzazione di componenti per il settore automotive e per l'aeronautica, per le applicazioni medicali, per l'impiego strutturale, nella nautica e nelle attrezzature sportive. Per le caratteristiche di smorzamento delle vibrazioni e del rumore e per il comportamento ignifugo sono inoltre applicabili in molti altri prodotti, dai beni strumentali per l'industria all'edilizia. Nonostante a questa tipologia di materiali venga dedicato, particolarmente negli ultimi anni, un crescente interesse scientifico, le ricadute applicative sono ancora frenate dalla scarsa disponibilità di conoscenze tecnologiche sulla lavorazione meccanica delle schiume. Unitamente all'approfondimento sulle caratteristiche reologiche dei materiali cellulari a base metallica e sulle modalità di riempimento di componenti cavi (tubi, shell, etc.), il progetto TILAS si propone di indagare le tecnologie di trasformazione (taglio, deformazione, saldatura) delle schiume metalliche e dei componenti riempiti. A tal fine le cinque U.R. del progetto, che hanno avuto precedenti occasioni per lo sviluppo di collaborazioni scientifiche, si sono coordinate per analizzare le problematiche tecnologiche dei principali processi di trasformazione delle schiume e per evidenziare potenziali vantaggi e limitazioni della applicazione delle schiume metalliche ad alcuni prodotti esemplificativi utilizzati come casi di studio (serbatoio idrogeno, telaio motociclistico, componenti strutturali per l'automobile, etc.). Testo inglese The research project TILAS (Innovative Manufacturing Technologies for Metal Foams) has the aim to contribute to increase the knowledge of the industrial application of cellular materials. Nowadays metal foams are an interesting alternative to composite materials in the production of a wide range of components in different fields as: automotive, aeronautics, medical applications, nautical constructions and sport equipments. As they provide good damping behaviour and are fire-resistant, metal foams can be applied also in buildings and civil constructions. In the last years, metal foams are receiving an increasing scientific interest; nevertheless industrial applications are limited from the lack of knowledge on metal foams machining. Together with the deepening on rheological properties of metal based cellular materials and the various filling methods for hollow components (tubes, shell, etc.), the project TILAS focus the research on the transformation technology (milling, deformation, joining) of the metal foams and filled components. With this purpose the five U.R., that had past scientific collaboration experience, are coordinated to analyze the technological problems of metal foams machining and to highlight potential advantages and drawback of the application of metal foams to some products used as case study (hydrogen pressurized vessel, automotive structural components, etc.)

LA RIVISTA STORICA DEDICATA ALLE FONDERIE La rivista Fonderia Pressofusione continua a essere un ... more LA RIVISTA STORICA DEDICATA ALLE FONDERIE La rivista Fonderia Pressofusione continua a essere un insostituibile strumento per l\u2019aggiornamento professionale delle fonderie ferrose e non ferrose. Con la presentazione di nuove macchine e di nuovi impianti, con ampi articoli applicativi realizzati direttamente nelle fonderie, con gli articoli tecnici dedicati ai processi di fusione e alle tecniche di produzione, Fonderia Pressofusione segue il passo di un settore in continuo rinnovamento e che fa dell\u2019innovazione tecnologica la sua arma vincente

The main practical policy objective of EuMaT is to assure optimum involvement of industry and oth... more The main practical policy objective of EuMaT is to assure optimum involvement of industry and other important stakeholders in the process of establishing European R&D priorities in the area of advanced engineering materials and technologies. EuMaT should improve coherence in existing and forthcoming EU projects, and introduce \u201cRadical Changes\u201d and assure \u201cSustainable Development\u201d in the sector of advanced engineering materials and related technologies. EuMaT covers all elements of the life cycle of \u201cAdvanced Engineering Materials & Technologies\u201d (AEMT). The term AEMT refers in EuMaT to the three pillars 1. multifunctional materials, 2. Materials for extreme conditions 3. Hybrid & Multimaterials as used in engineering (and, e.g., coupled with \u201cconventional\u201d structural materials like steel, aluminum, titanium, metallic alloys, composites, polymers, advanced ceramics, coatings, adhesives, concrete, \u2026) and/or used to enhance the engineering products, systems and processes in areas like energy, gas & oil, chemical, space, transportation, electronics, environment, health, etc. EuMaT covers the lifecycle of lightweight materials and nanomaterials in engineering components/ applications/systems. In particular it clearly points out the link toward large European projects like KMM-NoE (www.kmm-noe.org) and Extremat (http://www.extremat.org), in which advanced engineering materials like intermetallics, metal ceramic composites, functionally graded materials, self-passivating protection materials, radiation resistant materials and heat sink materials and high-temperature materials are investigated. The examples of advanced new products directly enabled by the progress in the area of advanced engineering materials are, e.g., gas and steam turbines (for 1600 \ubaC and 800 \ubaC respectively, ITER reactor or the \u201cThird Millennium Car\u201d). The advanced engineering materials will have a similar impact in the area of manufacturing (cf. the MANUFUTURE Technology platform)

L'articolo prende in analisi i metodi e gli impianti in funzione della precisione dimensional... more L'articolo prende in analisi i metodi e gli impianti in funzione della precisione dimensionale e di forma che pu\uf2 essere assicurata sul prodotto finale. In particolare sono analizzate le architetture delle macchine per la pressofusione e degli stampi al fine di individuare quelli in grado di assicurare migliore precisione dei getti

La tempra \ue8 un processo che, per sua natura, determina una variazione dimensionale dei compone... more La tempra \ue8 un processo che, per sua natura, determina una variazione dimensionale dei componenti rendendo necessarie costose lavorazioni successive al trattamento termico. La simulazione di processo e la tempra in pressa possono essere due strumenti strategici per riuscire a trattare componenti meccanici di precisione senza la necessit\ue0 di realizzare ulteriori lavorazioni. L\u2019attivit\ue0 presentata ha avuto l\u2019obiettivo di pianificare e realizzare una sperimentazione volta a ottenere i dati numerici da impiegare per la validazione del modello matematico del processo di tempra

I termini tecnici che sono comunemente utilizzati in fonderia costituiscono, come accade anche in... more I termini tecnici che sono comunemente utilizzati in fonderia costituiscono, come accade anche in altri settori della tecnologia, un vero e proprio gergo. La difficolt\ue0 maggiore, quando ci si avvicina alle tecnologie fusorie, consiste non tanto nell\u2019apprendimento del vocabolario di settore, ma molto spesso nel fatto che esiste una certa confusione a causa di termini tecnici simili che nella pratica quotidiana hanno significati e utilizzi diversi. A questo proposito, ad esempio, il termine \u201ccolata in conchiglia\u201d pu\uf2 indurre a pensare a tutt\u2019altra cosa che ad un processo produttivo. Un esempio fra tutti siano ancora i termini pressofusione e iniettofusione, che esamineremo a breve. Altrettanto difficoltosa pu\uf2 risultare, talvolta, la traduzione da altra lingua. Infatti, non sempre esiste il termine tecnico corrispondente. Proprio in questo periodo mi \ue8 successo di cercare la traduzione italiana di un termine che definisce una particolare conformazione geometrica del sistema di riempimento nella pressofusione che in altre lingue assume una definizione specifica. Poich\ue9 la ricerca \ue8 stata infruttuosa allora \ue8 stato necessario ricorrere ad una lunga locuzione che, a mio parere, ha portato inoltre ad una perdita d\u2019informazione. Prendiamo, quindi, in considerazione alcuni termini tecnici che saranno ampiamente utilizzati in queste pagine ed esaminiamone il significato insieme alla traduzione in alcune lingue europee. In Gran Bretagna i termini \u201cdie casting\u201d oppure, con maggiore precisione, \u201cgravity die casting\u201d corrispondono a \u201ccolata in conchiglia a gravit\ue0\u201d; \u201cpressure die casting\u201d oppure \u201chigh pressure die casting\u201d si traduce con \u201cpressofusione\u201d, con le dovute attenzioni che vedremo. Altrettanto usato e il termine \u201cchill casting\u201d, che \ue8 pi\uf9 generico. Negli USA si usa distinguere: \u201cpermanent mold casting\u201d, \u201csemi-permanent mold casting\u201d e \u201cdie casting\u201d. I primi due processi corrispondono all\u2019italiano colata in conchiglia a gravit\ue0. Gli statunitensi sono per\uf2 pi\uf9 meticolosi e distinguono due differenti processi a seconda che, rispettivamente, si utilizzino o no tasselli o anime in sabbia. L\u2019ultime termine corrisponde alla \u201ccolata sotto pressione\u201d. In tedesco la terminologia tecnica \ue8 assai precisa: la colata in conchiglia a gravit\ue0 si traduce con \u201cKokillenguss\u201d; la colata sotto pressione in camera calda ovvero la \u201ciniettofusione\u201d diventa \u201cSpritzguss\u201d e infine la colata sotto pressione in camera fredda ovvero la \u201cpressofusione\u201d propriamente detta diventa \u201cPressguss\u201d. E\u2019 necessaria una precisazione sul termine iniettofusione. Tale termine \ue8 raramente utilizzato in fonderia ed \ue8 comunemente sostituito dallo stesso pressofusione. Il termine \u201cpressocolata\u201d \ue8 forse preferibile, infine, ad entrambi i termini pressofusione o iniettofusione, in quanto descrive in modo pi\uf9 generale, preciso e sintetico il processo di colata sotto pressione. Ciononostante nel gergo di fonderia si utilizza molto spesso il termine pressofusione al posto di pressocolata. Nel seguito prenderemo in considerazioni i processi di formatura da liquido di cui si \ue8 brevemente discusso

Smart Innovation, Systems and Technologies, 2017

The Smart Innovation, Systems and Technologies book series encompasses the topics of knowledge, i... more The Smart Innovation, Systems and Technologies book series encompasses the topics of knowledge, intelligence, innovation and sustainability. The aim of the series is to make available a platform for the publication of books on all aspects of single and multidisciplinary research on these themes in order to make the latest results available in a readily-accessible form. Volumes on interdisciplinary research combining two or more of these areas is particularly sought. The series covers systems and paradigms that employ knowledge and intelligence in a broad sense. Its scope is systems having embedded knowledge and intelligence, which may be applied to the solution of world problems in industry, the environment and the community. It also focusses on the knowledge-transfer methodologies and innovation strategies employed to make this happen effectively. The combination of intelligent systems tools and a broad range of applications introduces a need for a synergy of disciplines from science, technology, business and the humanities. The series will include conference proceedings, edited collections, monographs, handbooks, reference books, and other relevant types of book in areas of science and technology where smart systems and technologies can offer innovative solutions. High quality content is an essential feature for all book proposals accepted for the series. It is expected that editors of all accepted volumes will ensure that contributions are subjected to an appropriate level of reviewing process and adhere to KES quality principles.

Lightweight design is often assumed to be the leading strategy to improve the sustainability of p... more Lightweight design is often assumed to be the leading strategy to improve the sustainability of parts produced by additive manufacturing. The present study confutes such an assumption by a cradle-to-gate life cycle assessment of different lightweight strategies applied to a specific case study in the medical field. In particular, a patient-specific finger splint made of polyamide is redesigned by means of generative design, topology optimization and lattice structures. The analysis investigates two markedly different deposition processes, namely Arburg plastic freeforming and fused filament fabrication. The former is carried out on an industrial-grade machine, while a desktop printer is used for the latter. This allows for observing the impact of the redesign in two quite distinct scenarios. Findings demonstrate that, since environmental impacts are mainly driven by building time, the adoption of automated design algorithms can be detrimental to the sustainability of the process. On the other hand, relevant benefits on environmental impacts were achieved by reducing the infill percentage of parts. The results of this work highlight the most relevant aspects which must be considered to limit environmental impacts when designing parts for deposition-based additive manufacturing. This information can be used by designers to drive weight reduction towards sustainability.

Laser hardening is a laser assisted process devoted to the surface hardening of the mechanical co... more Laser hardening is a laser assisted process devoted to the surface hardening of the mechanical components. This process is highly suitable for medium carbon steels with carbon content comprised between 0.2 - 0.6% or for low alloy steels which are usually surface hardened during their manufacturing process. Laser hardening technology is gaining a great industrial interest in the last years in fact, the possibility of integrating the heating source directly on the production line, together with the absence of the quenching medium, meets the production needs of modern industries. Laser hardening optimization could be complex especially when tempering due to multiple passes effects must be considered. Many research studies have been proposed in the last years with the aim to predict the optimal laser process parameters such as laser power density, laser beam velocity and scanning strategies. Many Authors agree with the assumption that the whole austenite resulting from the heating is transformed into martensite during the quenching. This is a valid approximation for single pass but could be a rough hypothesis in multiple-passes when the cooling rate could be in laser hardening, hysteresis phenomena should be taken into account for pearlite to austenite and martensite to austenite transformations during heating and martensite tempering during multiple passes. In this paper the crucial problems that have to be faced in laser surface hardening modelling are discussed according to the current literature. In particular, partial austenitization of the pearlite is suggested as a solution of the hardness prediction of the profile depth. Then three transformation parameters are proposed to take into account the hysteresis phenomena in martensite and pearlite transformations into austenite and martensite tempering.Finally, experimental examples are proposed to validate the assumptions

LPM2012 (the 13th International Symposium on Laser Precision Microfabrication), 2012

This paper presents the recent results in micro-welding of nearly eutectoid steels obtained with ... more This paper presents the recent results in micro-welding of nearly eutectoid steels obtained with a nanosecond pulsed laser. By using this source, good penetration depth and seam geometry can be obtained with minimum energy delivered to the work piece, and minimum heat affected zone, if compared to long pulse laser sources or low energy density sources. Moreover, by using appropri- ated controlled axes, high welding rates and high flexibility, in terms of seam paths, are easily ob- tained. A numerical simulation of micro-welding of nearly eutectoid steels by nanosecond pulsed laser is carried out to evaluate the weld pool dimension and the heat-affected zone extension

LAMIERA 2006. Prospettive nelle lavorazioni laser delle lamiere, 2006

Proceedings of the 7th AITeM Conf. - Enhancing the Science of Manufacturing, 2005

This paper analyses the modelling of conduction losses in laser-material interaction. The incomin... more This paper analyses the modelling of conduction losses in laser-material interaction. The incoming laser energy is evaluated by means of a non linear system equation which allows to calculate the physical state and the shielding effect of the plasma plume. The conduction losses were in particular evaluated by means of several models in order to understand the applicability of each one in relation to power intensity. Their influence has been tested by means of welding experiments with a 3 kW CO2 laser source, where penetration depths on an AISI 304 stainless steel were measured. Samples were extracted from the weld seams and geometric and microstructure evaluations were performed in order to verify the analytical models. Some of the considered conduction losses models evidenced good predicting capabilities in the range of the investigated parameters

In this paper a numerical model for simulation of hypo eutectoid steel laser hardening process is... more In this paper a numerical model for simulation of hypo eutectoid steel laser hardening process is presented. The Finite Difference Method (FDM) was used to solve the heat transfer and the carbon diffusion equations for defined workpiece geometry. The model is able to predict the thermal cycle into the target material, the phase transformations and the resulting microstructures according to the laser process parameters, the workpiece dimensions and the physical properties of the workpiece. The effects of the overlapping laser beam tracks on the resulting microstructures can be also considered. Besides the original material microstructure is taken into account in the simulation process by means of a digitized photomicrograph in which the initial ferrite-pearlite distribution is acquired. Several experimental tests were then carried out on a torque limiter hub made of C43 UNI 7847 and laser hardened by means of CO2 laser or induction source. The comparisons were made between the geometry of the two different surface hardenings and the hardness profiles

Si affronta la tecnologia della tempra laser attraverso la modellazione del processo e attivit\ue... more Si affronta la tecnologia della tempra laser attraverso la modellazione del processo e attivit\ue0 sperimentale. Il modello implementato secondo il metodo alle differenze finite consente di prevedere il ciclo termico, le fasi microstrutturali presenti nella zona trattata e la conseguente durezza mediante due metodi differenti. Il primo metodo calcola la durezza attraverso la conoscenza della composizione microstrutturale. Il secondo metodo valuta il profilo di durezza attraverso un modello empirico che necessita di una taratura attraverso i dati sperimentali

The present work defines a strategy to perform an automatic setup procedure for a laser milling m... more The present work defines a strategy to perform an automatic setup procedure for a laser milling manufacturing process. The manufacturing system is constituted by a milling CNC machine structure coupled with a DPSS Nd:YAG Laser source. This work shows the criteria developed to evaluate the influence of process parameters on material removal rate when processing mild steels and aluminium alloys. The method, based on a statistical approach, was performed by experiments executed using DOE techniques and developing a regression model validated by a ANOVA Analysis. It can be easily applied to other materials and it represents an useful tool to asses the right process parameters in roughing and in finishing operations. A basic manual approach is presented and the automatic procedure developed is in detail explained. The implemented Software System automatically generates a part program to laser milling a set of pockets, using different laser parameters, then permit to scan them by an optical sensor and to calculate the empirical coefficients to use in the regression model that provide the material removal rate

Smart Innovation, Systems and Technologies, 2017

LPM2012 (the 13th International Symposium on Laser Precision Microfabrication), 2012

LAMIERA 2006. Prospettive nelle lavorazioni laser delle lamiere, 2006

Proceedings of the 7th AITeM Conf. - Enhancing the Science of Manufacturing, 2005