ADVANCED MATERIALS & PROCESSES | JANUARY/FEBRUARY 2025 15 This article concludes a two-part series on the bronze cymbal making process as performed by ancient metalworkers and modern cymbalsmiths. The process is described and examined through both historical context and cymbal metallurgy. The culture and metalworking traditions of a country influence the type of cymbals made, the manner in which musicians play them, and how these instruments are used in society. The cymbals examined for this article are of Turkish origin and manufactured using ancient practices, which remain largely unchanged. The Turkish process of cymbal making begins by melting a tin-copper combination and pouring the molten metal into open molds (bowls)—one casting per mold. The chemical composition of the bronze is ~20% Sn and ~80% Cu. The basic process of casting, rolling, hammering, and lathing (metal turning) remains customary practice in modern times with only minor changes, for example, the use of machinery powered by electrical, pneumatic, or hydraulic technology. Beginning in the late 18th century, at which time modern rolling methods appear, the introduction of two-high rolling mills (i.e., two horizontal rolls, one over the other, each roll turning opposite the other) for hot rolling iron would eventually be adapted by cymbalsmiths, who used the two-high mills for reducing bun castings into specific sized blanks. This new practice of hot rolling, working the hot metal above crystallization temperature, provided much improved gauge-thickness consistency as well as accurate dimensional tolerances and allowed development of specific reduction schedules. The applied force of the rolls reduced material thickness with each successive roll-pass, changing both the shape and internal microstructure of the castings. Following the reduction steps, cold working begins (hammering, forming, and bending). The metallurgy of two samples examined at this point in the process indicates equiaxed grain structure. The microstructure consists of copper-rich metallic grains and tin-rich grains with fine inter- metallic precipitates. Microstructure shows twinning and signs of light cold working in the metallic grains. Both samples have inclusions of varying morphologies. Using color thresholding, analysis of the phase constituents of the microstructure revealed a copper-rich alpha phase composition of 50% and 52%, respectively. The remainder of the microstructure is composed of tin-rich grains with fine intermetallic precipitates, pro- ducts of decomposition of the high-temperature Cu-Sn phase. Analysis confirms an insignifi- cant volume fraction of inclusions[1]. This type of micro- structure contributes to the ease of cold working and eventually the sound of a cymbal. FORMING PRESS Another late 18th century manufacturing advancement that helped the efficiency of cymbalsmiths and integrated into the cymbal making process is the metal forming press. The use of a machine press for hot forming a bell onto a blank, versus hammering the bell, saved much time and offered advantages including extended production runs and a consistent, if not precise bell shape, allowing a given cymbal line (same model) uniform and repeatable bell shape and, surmising downstream operations adhered to standard manufacturing practices, sound characteristics within an expected range (Table 1). For efficiency, metalworkers perform the Zildjian workers outside of early manufacturing facility, circa 1929. Seated from left: Puzant Zildjian, Aram Zildjian, Avedis Zildjian III, and Avedis Varteresian. TABLE 1 — BELL SIZE AND ASSOCIATED SOUND CHARACTERISTICS Bell shape Sound characteristics Small High pitch, short sustain Large Low pitch, long sustain Low profile Less sustain High profile Bright Thin walled Low pitch, less sustain Thick walled High pitch, more sustain
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