|
Honjo Masamune
, was a medieval Japanese blacksmith widely acclaimed as Japan's greatest swordsmith. He created swords and daggers, known in Japanese as ''tachi'' and ''tantō'', in the ''Sōshū'' school. However, many of his forged ''tachi'' were made into ''katana'' by cutting the tang (''nakago'') in later times. For this reason, his only existing works are ''katana'' and ''tantō''.相州伝の名工「正宗」. Nagoya Japanese Sword Museum Touken World. No exact dates are known for Masamune's life. It is generally agreed that he made most of his swords between 1288 and 1328. Some stories list his family name as Okazaki, but some experts believe this is a fabrication to enhance the standing of the |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans Japanese archipelago, an archipelago of List of islands of Japan, 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa Island, Okinawa. Tokyo is the Capital of Japan, nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the List of countries and dependencies by population, eleventh most populous country in the world, as well as one of the List of countries and dependencies by population density, most densely populated and Urbanization by country, urbanized. About three-fourths of Geography of Japan, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martensite
Martensite is a very hard form of steel crystalline structure. It is named after German metallurgist Adolf Martens. By analogy the term can also refer to any crystal structure that is formed by diffusionless transformation. Properties Martensite is formed in carbon steels by the rapid cooling (quenching) of the austenite form of iron at such a high rate that carbon atoms do not have time to diffuse out of the crystal structure in large enough quantities to form cementite (Fe3C). Austenite is gamma-phase iron (γ-Fe), a solid solution of iron and alloying elements. As a result of the quenching, the face-centered cubic austenite transforms to a highly strained body-centered tetragonal form called martensite that is supersaturated with carbon. The shear deformations that result produce a large number of dislocations, which is a primary strengthening mechanism of steels. The highest hardness of a pearlitic steel is 400 Brinell, whereas martensite can achieve 700 Bri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokugawa Yoshimune
was the eighth ''shōgun'' of the Tokugawa shogunate of Japan, ruling from 1716 until his abdication in 1745. He was the son of Tokugawa Mitsusada, the grandson of Tokugawa Yorinobu, and the great-grandson of Tokugawa Ieyasu. Lineage Yoshimune was not the son of any former ''shōgun''. Rather, he was a member of a cadet branch of the Tokugawa clan. Tokugawa Ieyasu, the founder of the Tokugawa shogunate, well aware of the extinction of the Minamoto line in 1219, had realized that his direct descendants might die out, leaving the Tokugawa family at risk of extinction. Thus, while his son Tokugawa Hidetada was the second ''shōgun'', he selected three other sons to establish the ''gosanke,'' hereditary houses which would provide a ''shōgun'' if there were no male heir. The three ''gosanke'' were the Owari, Kii, and Mito branches. Yoshimune was from the branch of Kii. The founder of the Kii house was one of Tokugawa Ieyasu's sons, Tokugawa Yorinobu. Ieyasu appointed him ''daimyō ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kyōhō
, also pronounced Kyōho, was a after '' Shōtoku'' and before '' Gembun.'' This period spanned the years from July 1716 through April 1736. The reigning emperors were and . Change of era * 1716 : The era name of ''Kyōhō'' (meaning "Undergoing and Supporting") was created in response to the death of Tokugawa Ietsugu. The previous era ended and the new one commenced in ''Shōtoku'' 6, on the 22nd day of the 6th month. Events of the ''Kyōhō'' era * 1717 (''Kyōhō 2''): ''Kyōhō'' reforms are directed and overseen by Shōgun Yoshimune. * 1718 (''Kyōhō 3''): The ''bakufu'' repaired the Imperial mausolea.Ponsonby-Fane, Richard. (1956). ''Kyoto: the Old Capital, 794–1869'', p. 320. * 1718 (''Kyōhō 3, 8th month''): The ''bakufu'' established a at the office of the ''machi-bugyō'' in Heian-kyō. * 1720 (''Kyōhō 5, 6th month''): The 26th High Priest of Nichiren Shōshū, Nichikan Shōnin, who is considered a great reformer of the sect, inscribed the Gohonzon which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daimyō
were powerful Japanese magnates, feudal lords who, from the 10th century to the early Meiji era, Meiji period in the middle 19th century, ruled most of Japan from their vast, hereditary land holdings. They were subordinate to the shogun and nominally to the Emperor of Japan, emperor and the ''kuge''. In the term, means 'large', and stands for , meaning 'private land'. From the ''shugo'' of the Muromachi period through the Sengoku period, Sengoku to the ''daimyo'' of the Edo period, the rank had a long and varied history. The backgrounds of ''daimyo'' also varied considerably; while some ''daimyo'' clans, notably the Mōri clan, Mōri, Shimazu clan, Shimazu and Hosokawa clan, Hosokawa, were cadet branches of the Imperial family or were descended from the ''kuge'', other ''daimyo'' were promoted from the ranks of the samurai, notably during the Edo period. ''Daimyo'' often hired samurai to guard their land, and they paid the samurai in land or food as relatively few could aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nanboku-chō Period
The Nanboku-chō period (南北朝時代, ''Nanboku-chō jidai'', "North and South court period", also known as the Northern and Southern Courts period), spanning from 1336 to 1392, was a period that occurred during the formative years of the Muromachi (Ashikaga) shogunate of Japanese history.During the early period, there existed a Northern Imperial Court, established by Ashikaga Takauji in Kyoto, and a Southern Imperial Court, established by Emperor Go-Daigo in Yoshino. Ideologically, the two courts fought for 50 years, with the South giving up to the North in 1392. However, in reality the Northern court was under the power of the Ashikaga shogunate and had little real independence. The destruction of the Kamakura shogunate of 1333 and the failure of the Kenmu Restoration in 1336 opened up a legitimacy crisis for the new shogunate. Institutional changes in the estate system ('' shōen'') that formed the bedrock of the income of nobles and warriors altered the status of the var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shogun
, officially , was the title of the military dictators of Japan during most of the period spanning from 1185 to 1868. Nominally appointed by the Emperor, shoguns were usually the de facto rulers of the country, though during part of the Kamakura period, shoguns were themselves figureheads, with real power in hands of the Shikken of the Hōjō clan. The office of shogun was in practice hereditary, though over the course of the history of Japan several different clans held the position. The title was originally held by military commanders during Heian period in the eighth and ninth centuries. When Minamoto no Yoritomo gained political ascendency over Japan in 1185, the title was revived to regularize his position, making him the first shogun in the usually understood sense. The shogun's officials were collectively referred to as the ; they were the ones who carried out the actual duties of administration, while the Imperial court retained only nominal authority.Beasley, William G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokugawa Shogunate
The Tokugawa shogunate (, Japanese 徳川幕府 ''Tokugawa bakufu''), also known as the , was the military government of Japan during the Edo period from 1603 to 1868. Nussbaum, Louis-Frédéric. (2005)"''Tokugawa-jidai''"in ''Japan Encyclopedia'', p. 978.Nussbaum"''Edo-jidai''"at p. 167. The Tokugawa shogunate was established by Tokugawa Ieyasu after victory at the Battle of Sekigahara, ending the civil wars of the Sengoku period following the collapse of the Ashikaga shogunate. Ieyasu became the ''shōgun,'' and the Tokugawa clan governed Japan from Edo Castle in the eastern city of Edo (Tokyo) along with the ''daimyō'' lords of the ''samurai'' class.Nussbaum"Tokugawa"at p. 976. The Tokugawa shogunate organized Japanese society under the strict Tokugawa class system and banned most foreigners under the isolationist policies of ''Sakoku'' to promote political stability. The Tokugawa shoguns governed Japan in a feudal system, with each ''daimyō'' administering a ''han'' (f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hōki Province
was an old province of Japan in the area that is today the western part of Tottori Prefecture. It was sometimes called . Hōki bordered on Inaba, Mimasaka, Bitchū, Bingo, and Izumo Provinces. The ancient capital was in the area that is now Kurayoshi, and a major castle town was at Yonago. Maps of Japan and Hōki Province were reformed in the 1870s when the prefecture system was introduced. At the same time, the province continued to exist for some purposes. For example, Hōki is explicitly recognized in treaties in 1894 (a) between Japan and the United States and (b) between Japan and the United Kingdom.US Department of State. (1906) ''A digest of international law as embodied in diplomatic discussions, treaties and other international agreements'' (John Bassett Moore, ed.), Vol. 5, p. 759 Historical districts * Tottori Prefecture ** Aimi District (会見郡) - merged with Aseri District to become Saihaku District (西伯郡) on March 29, 1896 ** Aseri District ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quenched
In materials science, quenching is the rapid cooling of a workpiece in water, oil, polymer, air, or other fluids to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable, and kinetically accessible; for instance, quenching can reduce the crystal grain size of both metallic and plastic materials, increasing their hardness. In metallurgy, quenching is most commonly used to harden steel by inducing a martensite transformation, where the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. In steel alloyed with metals such as nickel and manganese, the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lowe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hamon (swordsmithing)
In swordsmithing, (from Japanese, literally "edge pattern") is a visible effect created on the blade by the hardening process. The hamon is the outline of the hardened zone (''yakiba'') which contains the cutting edge (''ha''). Blades made in this manner are known as differentially hardened, with a harder cutting edge than spine (''mune'') (for example: spine 40 HRC vs edge 58 HRC). This difference in hardness results from clay being applied on the blade (''tsuchioki'') prior to the cooling process (quenching). Less or no clay allows the edge to cool faster, making it harder but more brittle, while more clay allows the center (''hira'') and spine to cool slower, thus retaining its resilience.''A History of Metallography'' By Cyril Stanley Smith -- MIT Press 1968 Page 40--57 Introduction The hamon of a blade is created during the quenching process (''yakiire''). During the differential heat treatment, the clay coating on the back of the sword reduces the cooling speed of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tempering (metallurgy)
Tempering is a process of heat treating, which is used to increase the toughness of iron-based alloys. Tempering is usually performed after hardening, to reduce some of the excess hardness, and is done by heating the metal to some temperature below the critical point for a certain period of time, then allowing it to cool in still air. The exact temperature determines the amount of hardness removed, and depends on both the specific composition of the alloy and on the desired properties in the finished product. For instance, very hard tools are often tempered at low temperatures, while springs are tempered at much higher temperatures. Introduction Tempering is a heat treatment technique applied to ferrous alloys, such as steel or cast iron, to achieve greater toughness by decreasing the hardness of the alloy. The reduction in hardness is usually accompanied by an increase in ductility, thereby decreasing the brittleness of the metal. Tempering is usually performed after quench ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
