Search results
Results from the WOW.Com Content Network
Thermite (/ ˈθɜːrmaɪt /) [ 1 ] is a pyrotechnic composition of metal powder and metal oxide. When ignited by heat or chemical reaction, thermite undergoes an exothermic reduction-oxidation (redox) reaction. Most varieties are not explosive, but can create brief bursts of heat and high temperature in a small area.
Pitting corrosion. Appearance. Severe pitting corrosion problems caused by chloride ions on a truss beam of the Nandu River Iron Bridge (Hainan Province, China) leading to the complete rupture of a metallic element. Pitting corrosion, or pitting, is a form of extremely localized corrosion that leads to the random creation of small holes in metal.
A fire piston consists of a hollow cylinder sealed at one end and open at the other. Sizes range in length from 3 to 6 inches (7.5 to 15 cm) with a bore about 0.25 inch (6–7 mm) in diameter, to 10 to 14 inches (25 to 35 cm) with a bore about 0.5 inch (14 mm) in diameter. A piston with an airtight circular seal is fitted into the cylinder.
Bronze is an alloy consisting primarily of copper, commonly with about 12–12.5% tin and often with the addition of other metals (including aluminium, manganese, nickel, or zinc) and sometimes non-metals, such as phosphorus, or metalloids, such as arsenic or silicon. These additions produce a range of alloys that may be harder than copper ...
Pyrite is distinguishable from native gold by its hardness, brittleness and crystal form. Pyrite fractures are very uneven, sometimes conchoidal because it does not cleave along a preferential plane. Native gold nuggets, or glitters, do not break but deform in a ductile way. Pyrite is brittle, gold is malleable.
Fire making, fire lighting or fire craft is the process of artificially starting a fire. It requires completing the fire triangle , usually by heating tinder above its autoignition temperature . Fire is an essential tool for human survival and the use of fire was important in early human cultural history since the Lower Paleolithic .
Fire striker. Assorted reproduction firesteels typical of Roman to medieval period. Late 18th-century firetools and bricks from Brittany. A fire striker is a piece of carbon steel from which sparks are struck by the sharp edge of flint, chert or similar rock. [1][2][3] It is a specific tool used in fire making.
Flint, occasionally flintstone, is a sedimentary cryptocrystalline form of the mineral quartz, [ 1 ][ 2 ] categorized as the variety of chert that occurs in chalk or marly limestone. Historically, flint was widely used to make stone tools and start fires. Flint occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and ...