Nichrome ( NiCr , nickel-chrome , chrome-nickel , etc.) is one of a variety of nickel alloys , chromium, and often iron (and possibly other elements). The most common use is as resistance wire, although they are also used in some dental restorations (fillings) and in some other applications.
Video Nichrome
History
Patented in 1905, nikrom is the oldest form of heating alloys. A common nichrome alloy is 80% nickel and 20% chromium, with mass, but there are many other metal combinations for various applications. Nichrome is consistently silvery gray, corrosion-resistant, and has a high melting point of about 1,400 ° C (2,550 ° F). Due to the low manufacturing cost, strength, ductility, resistance to oxidation, high temperature stability, and resistance to electron flow, nikrom is widely used in in-house electrical heating elements such as hair dryers and hot guns. Typically, nikrom is wrapped in a coil to a certain electrical resistance, and when the current is passed through it, the Joule heater generates heat.
Maps Nichrome
Usage
Almost all conductive wires can be used for heating, but most metals conduct electricity with great efficiency, which requires it to be shaped into very thin and fine cables to create enough resistance to generate heat. When heated in the air, most metals then oxidize quickly, become brittle, and break. The Nichrome wire, however, when heated to a red-hot temperature, develops an outer layer of chromium oxide, which is thermodynamically stable in air, largely resistant to oxygen, and protects the heating element from further oxidation.
Nichrome is used in explosives and fireworks as a bridgewire in electric ignition systems, such as electric matches and model rocket sprayers.
Industrial hot wire foam cutter and hobby using nikrom wire.
Nichrome wire is usually used in ceramics as an internal support structure to help some elements of clay sculptures retain their shape while still soft. Nichrome wire is used because of its ability to withstand the high temperatures that occur when clay work is fired in a kiln.
Nichrome wire can be used as an alternative to platinum wire for flame testing by coloring non-glowing parts of the flame to detect cations such as sodium, potassium, copper, calcium, etc.
Other use areas include motorcycle exhaust, in certain areas of the microbiology laboratory, as a plastic heating element of the plastic extruder by the RepRap 3D printing community, in the spreading mechanism of the LightSail-A spacecraft solar panels, and as an electronic cigarette heating coil.
The alloy price is controlled by a more expensive nickel content. The distributor's price is usually indexed to market prices for nickel.
Properties
Nichrome alloys are known for their high mechanical strength and high elongation. The properties of nikrom vary depending on the alloy. The numbers given represent typical and accurate material for expressing significant numbers. Each variation is caused by a different percentage of nickel or chromium.
Table 1: Resistance per inch (?), Closed Helix, 80/20 alloy.
Tabel 2: Sekarang ( A) vs. karakteristik suhu, kabel lurus.
Displays the approximate current (in amperes) required to produce a certain temperature. Apply only to straight wires stretched horizontally in the free air. Values ​​for diameters from 0.040 "to 0.010" are based on scrolling on a 0.12 "chisel diameter and extending up to twice the length of the melee.
Table 3: Cold resistance (? at 75 Â ° F) and wire gauge vs. output power (W) at operating voltage (V).
In the following table, the alloys named nichrome V are defined as: 19-21% Cr, 2.5% Mn (max), 1.0% Fe (max), 0.75-1, 6% Si, 0.15% C (max), Ni balance.
Resistance nichrome flat/strip and table weight
- Effective cross-section width = Width ÃÆ'â € "Thickness ÃÆ'â €" 0.98
Additional properties
- NiCrA
- Chemical Composition: 80% Ni, 20% Cr
- Approx. Melting point: 1400 ° C
- NiCrC
- Chemical Composition: 61% Ni, 15% Cr, 24% Fe
- Approx. Melting point: 1350 ° C
See also
- Chromel
- Kanthal
- Inconel
- Hastelloy
- Constantan
References
Source of the article : Wikipedia
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