Metal is among the most versatile of artistic mediums; it can be shaped, bent, cut, or forged in limitless ways. Copper, steel, brass, and aluminum can be combined with one another or with alternate materials for a truly unique expression. However, most metals should first be strengthened in order for the resulting product to withstand the strains of time and environment. Some common treatments include:
1. Annealing and Quenching
Annealing is a process in which the metal’s crystalline structure is altered with heat; it is then slowly cooled or plunged into oil or water to quench it, essentially freezing the new crystal arrangement. Annealing increases a metal’s ductility, making it easier to work. While copper, silver, and aluminum are commonly quenched, steel is best heated gently then allowed to cool to room temperature.
2. Work Hardening
Also known as cold working, work hardening changes a metal’s structure by stressing material through hammering, bending, or cold forging. The metal gets stronger as its atoms are manipulated, allowing it to withstand further pressure. Work hardening requires no heating, lowers risks of material contamination, and is well-suited for copper, aluminum, and low carbon steel. Though cold working increases the metal’s hardness, it is possible to overwork the material and cause it to fracture rather than bend; it may take a bit of practice at first.
Soldering is one of the most common methods of joining like metals. Solder, a protective flux, and the metal sections are gently heated until the solder flows into the joint and seals the weld. Soldered links and joints are strong and can even be liquid tight if handled correctly. Soft soldering is useful for joining small pieces that would otherwise be damaged by high overall heating.
Brazing bears many similarities to soldering; the main difference is in the temperature used. Soldering is usually performed with a 430 degree flame. Brazing requires a larger flame of over 800 degrees. Brazing is used to join various metals to each other using a filler metal with a lower melting point than the parent pieces. This technique can also join metals to non-metals, such as metalized ceramics.
Brazing stainless steel makes the metal extremely strong. A stainless steel piece requires a specialized flux in order to protect its surface against oxidation, but it forms a strong, permanent bond. Silver is often the filler metal of choice when brazing stainless steel.
All metals have unique characteristics and respond to strengthening methods in different ways. Practice and explore various techniques and expand your repertoire with alternate materials, methods, and artistic touches.