La tecnologia laser nella pulitura dei manufatti lapidei, casi studio a confronto

Bartolomeo Megna, Rossella Licciardi

Research output: Contribution to conferenceOtherpeer-review

Abstract

[automatically translated] In this paper we present the experiments conducted as part of a Master thesis in Single Cycle in Conservation and Restoration of Cultural Heritage, at the Institute of Applied Physics "Nello Carrara" of the National Research Council of Florence, accounted for the potential of different regimes laser Nd: YAG laser at 1064 nm: Short Free Running (30-110 mS) and Long Q-Switch in single, double and triple pulse (120 ns spaced 40 mS). For this purpose were selected fragments of stone artefacts, different historical period, dating from the seventeenth century BC and the twentieth century, which offered special interest conservation problems. The knowledge of these artifacts and phenomena of degradation present on them has been deepened through the synergistic use of various investigative techniques, from non-destructive, such as Raman Microscopy, Reflection Screen Vis-NIR and colorimetric measurements. Subsequently, were conducted the sampling and analysis of micro-samples, studied with the aid of Optical Microscopy, into visible light and fluorescence, Scanning Electron Microscopy (SEM) and elemental chemical microanalysis EDS (Energy Dispersive Spectrometry RX ). On selected artifacts we were conducted laser ablation trials, using different operating modes, in order to identify the damage thresholds and fluence operating ranges suitable and paying particular attention to assessing the efficiency of the cleaning process. The effects of irradiation and the different levels of cleaning obtained were evaluated in depth thanks to the help of colorimetric comparisons and implementation of cross section, observed and analyzed by Optical Microscopy and Electronics. By varying the operating conditions it was possible to obtain optimum cleaning levels, in accordance with the complexity of the different treated surfaces, and sift through all the possible implications of the use of a scheme or another, in order to implement a correct, timely and selective conservative intervention, specific to the cases examined study.
Original languageItalian
Pages1-1
Number of pages1
Publication statusPublished - 2014

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