METHOD OF RESTORATION OF SOUND CHARACTERISTICS OF METAL CAST PERCUSSION MUSICAL INSTRUMENT Russian patent published in 2009 - IPC C22F1/08 B23P6/04 

FIELD: metallurgy.

SUBSTANCE: invention relates to restoration of damaged hardware, namely to the methods of fixing the defects in metal percussion musical instruments and can be used to fix the defects in the bells, improve their acoustic and strength properties. A defect, for instance a through crack is sealed from the outdoor environment with padding made from a non-ferrous metal or alloy and the instrument is heated in the gas environment at pressure of 1000-2000 atmospheres to the temperature of plastic deformation of the instrument material and keep for at least an hour. Then the pressure is reduced by 2-3 times and the instrument is kept for 3 hours minimum, which is then followed by pressure release to the atmospheric level with the following temperature reduction to the room temperature for as long as it is required for the material to recrystallise. Neutral gas environment is used, for instance inert gas environment. The padding is welded or soldered to the instrument surface using a metal plate or solder alloy or the adding material close by the composition to the instrument material as a padding. Before welding the defect site on the instrument is degrease with an organic solvent, for example acetone.

EFFECT: fixed internal and external defects of the instrument material such as cracks, bubbles, pipes, slag inclusions and fine clear sound.

5 cl, 11 dwg