Shibuichi
Encyclopedia
is an alloy which can be patina
ted into a range of subtle muted shades of blue or green. Its name means "one-fourth" in Japanese
and indicates the standard formulation of one part silver
to three parts copper
, though this may be varied according to the desired effect. A 5% silver / 95% copper alloy is also marketed as "shibuichi" . A wide range of colours can be achieved using the whole range of alloy compositions, even above 50% silver. It is a common misconception that both copper and silver oxides form but in fact a detailed study has shown that only copper oxides are formed on the copper rich regions of the materials microstructure while the silver rich regions are left largely untouched.
For most of its history, shibuichi was mostly used to ornament various fittings for katana
until the Meiji
reforms, when most swordmakers began to make purely decorative objects instead. Similar alloys have been used elsewhere but the use of shibuichi to achieve different colored patinas has remained nearly unknown outside Japan, despite recent interest from artisans in the West.
Patina
Patina is a tarnish that forms on the surface of bronze and similar metals ; a sheen on wooden furniture produced by age, wear, and polishing; or any such acquired change of a surface through age and exposure...
ted into a range of subtle muted shades of blue or green. Its name means "one-fourth" in Japanese
Japanese language
is a language spoken by over 130 million people in Japan and in Japanese emigrant communities. It is a member of the Japonic language family, which has a number of proposed relationships with other languages, none of which has gained wide acceptance among historical linguists .Japanese is an...
and indicates the standard formulation of one part silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...
to three parts copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
, though this may be varied according to the desired effect. A 5% silver / 95% copper alloy is also marketed as "shibuichi" . A wide range of colours can be achieved using the whole range of alloy compositions, even above 50% silver. It is a common misconception that both copper and silver oxides form but in fact a detailed study has shown that only copper oxides are formed on the copper rich regions of the materials microstructure while the silver rich regions are left largely untouched.
For most of its history, shibuichi was mostly used to ornament various fittings for katana
Katana
A Japanese sword, or , is one of the traditional bladed weapons of Japan. There are several types of Japanese swords, according to size, field of application and method of manufacture.-Description:...
until the Meiji
Meiji period
The , also known as the Meiji era, is a Japanese era which extended from September 1868 through July 1912. This period represents the first half of the Empire of Japan.- Meiji Restoration and the emperor :...
reforms, when most swordmakers began to make purely decorative objects instead. Similar alloys have been used elsewhere but the use of shibuichi to achieve different colored patinas has remained nearly unknown outside Japan, despite recent interest from artisans in the West.
External links
- Reactive Metal Studio Inc. -- Shakudo & Shibuichi Data Sheet
- http://www.schichtwerk.com/ semi-finished mokume gane material of the highest quality and resilience made in Germany