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

FIELD: metallurgy.

SUBSTANCE: invention relates to restoration of damaged metal articles, namely to the methods of fixing internal defects in cast percussion musical instruments occurring at the time of using the instruments as well as during manufacturing them and the invention can be used to fix the defects of bells. The instrument is heated in the gaseous medium under the pressure of 1000-2000 atm to reach the temperature of plastic flow of the instrument material and it is kept for as long as one hour minimum. 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 instrument material to recrystallise. Neutral gas environment is used, for instance, inert gas environment.

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

2 cl, 9 dwg