Parfenov Vadim A. — Doctor of Technical Sciences, associate professor; Saint-Peterburg Institute of History of Russian Academy of Sciences, leading research fellow;
Saint Petersburg Electrotechnical University, professor;
Immanuel Kant Baltic Federal University, professor
E-mail: vadim_parfenov@mail.ru

The article describes a new approach to the reconstruction of damaged and severely destroyed metal monuments, which is based on the use of the direct metal laser sintering technology. The results of experimental studies aimed at investigation of the possibility of its application are presented using the example of filling the losses on a fragment of a cast-iron fence of one of the tombstones of the XIX century in the Alexander Nevsky Monastery in St. Petersburg. This item is a cast decoration in the form of a multi-pointed star, which had multiple losses of elements. To reconstruct the “star”, its 3D laser scanning and computer 3D modeling were carried out. The 3D model obtained as a result of these works was transformed into a CAD model, which was used to manufacture the lost elements using a robotic laser machine. A nickel alloy powder with a granule size of 50–150 microns was used as a “building material” in the experiments. The melting of the metal powder was carried out using a continuous-wave fiber ytterbium laser with a wavelength of 1.06 microns and an output power of up to 80 watts. As a result of the high-precision movement of the laser beam along a given calculated trajectory, which led to the layered application of thin layers of molten metal, the missing elements of the “star” were reconstructed. Thus, the effectiveness of the proposed approach was proved. This work is the first experience of using laser additive technologies in Russia in the restoration of historical cast iron objects.

3D scanning, additive technologies, direct metal laser sintering, laser, metal monuments, reconstruction, restoration.