Phosphor bronze is an alloy of copper whose origin dates back almost 4000 years. The alloy is a mix of copper, tin, and phosphorus, and has been historically well known for high corrosion and wear resistance. The introduction of tin (from 0.5–11%) results in a significant increase in strength and corrosion resistance for the alloy, while the addition of phosphorous (from 0.1–0.35%) to this alloy increases its stiffness and wear resistance. The phosphor becomes a de-oxidant, reducing viscosity and improving the fluidity of the metal, which in turn improves its cast-ability.
Together, it is these qualities that make Phosphor Bronze an alloy of choice for multiple aesthetic and functional applications. Its flexibility and resistance have paved the way for its use in springs and bolts, electrical hardware, in the aerospace and marine industries, and even musical instruments, to name just a few applications. Beyond this, the metal boasts of outstanding malleability for bending and drawing, and can be easily plated, making it a versatile metallic medium for artists and designers.
Japanese artist Taiichiro Yoshida is one such creative, who has exploited the excellent malleability, strength and corrosion resistance of Phosphor Bronze to create highly intricate sculptures. Taiichiro creates the outer skins or wings of mammal and bird forms with an assemblage of hundreds of flowers, leaves and butterflies. Each delicate petal or leaf is handmade from phosphor bronze, and while fragile and lightweight in appearance, is robust both individually and en-masse. Taiichiro achieves the detailed nature of each tiny component through smithing–a painstaking process where hot metal is beaten and then formed into custom shapes, before being colored or plated. Smithing is an artisan skill through which makers create a wide variety of forms from metal bars (or ores).
On the one hand, Taiichiro relies on an ancient technique–decorative hot metalworking, which has been used in Japan since the 2nd or 3rd century BC–and on the other, he uses a modern, abstracted process to generate his forms. The outer shells of his sculptures–which are animals mostly–are created from tiny plant forms–a representation of our interdependent life on earth perhaps? The artist earned both his bachelor’s and master’s degrees in metal carving at the Tokyo National University of Fine Arts and Music, and his metalworking skills are evident in the sophisticated, nuanced sculptures he creates.
Since Phosphor Bronze displays no seasonal cracking or age-based hardening and is highly resistant to chemical and other types of corrosion, these intricate and beautiful sculptures are highly resilient, and will stand the test of time. Creatives such as Taiichiro have the option of working with Phosphor Bronze in a number of formats, from rods, to sheets of varied thickness (which can be cold formed into varied shapes) and even wire. Each format has good mechanical properties – such as spring or flexibility–allowing it be transformed in endless ways in the hands of an artist or designer.
Image credits: Colossal and Taiichiro Yoshida