Brass make brass was not recognised as a metal. The King James Bible makes many references to "brass". The Shakespearean English form of the word 'brass' can mean any bronze alloy, or copper, rather than the strict modern definition of brass. The earliest brasses may have been natural alloys made by smelting zinc-rich copper ores. By the Roman period brass was being deliberately produced from metallic copper and zinc minerals using the cementation process, and variations on this method continued until the mid-19th century. It was eventually replaced by speltering, the direct alloying of copper and zinc metal which was introduced
Microstructurally stable nanocrystalline alloys Microstructurally stable nanocrystalline alloys Microstructurally stable nanocrystalline alloys are alloys that are designed to resist microstructural coarsening under various thermo-mechanical loading conditions. Many applications of metal materials require that they can maintain their structure and strength despite very high temperatures. Efforts to prevent deformations from long term stress, referred to as creep, consist of manipulating alloys to reduce coarsening and migration of individual grains within the metal. The small size of individual metal grains provides high interfacial surface energy which is what prompts coarsening, the increase in grain size, and eventually metallic softening. Nanocrystalline creep is considered to follow the