ON THE DEBOSSING, ANNEALING AND MOUNTING OF BELLS

✍ Scribed by R PERRIN; G.M SWALLOWE; T CHARNLEY; C MARSHALL

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 178 KB
• Volume: 227
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1999.2352

✦ Synopsis

Changes in the frequencies of the musical partials of various types of bells following debossing dismounting/mounting and annealing/quench annealing are reported. Debossing, dismounting and quench annealing lead to frequency drops, while mounting gives rises. Annealing can lead to frequency increases or decreases depending upon the maximum temperature employed and the initial residual stress. Qualitative explanations of these phenomena are given in terms of changes in crown sti!ness, internal stress and alloy phase structure. These are supported by the results of X-ray di!raction measurements. Although the e!ects are all small they can be large enough to be detected by a reasonably musical car. This, together with the fact that the e!ects cannot be controlled, gives a plausible explanation of why modern bellfounders use vertical lathes for tuning, even with small carillon bells, and do not anneal bells when trying to control warble.