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#137 Nickel

Category : Metallic Materials
January18, 2013

Nickel can be used in materials of special metals or for electroplating on metal surfaces. Nickel is a silvery shiny metal.

Element symbolNi
Element number28
Specific gravity8,902
Melting point1,453℃
Specific heat0.105cal/gf・℃
Linear coefficient of expansion7.31×10-6
Thermal conductivity0.125cal/cm・sec・℃
Crystal latticeFace centered cubic structure

The purpose of use of nickel in molds is mainly to exploit its resistance to corrosion. Nickel is extremely stable in air, and does not react to oxidation or retardation. It is also stable in water or brine and does not generate rust. In particular, it exhibits remarkable resistance to sulfuric acid and hydrochloric acid

In addition, nickel is also used in a condition in which it is alloyed with other metallic elements.

Ni-CuUsed as the material for thermocouples
Ni-CrUsed as Nichrome wire of heaters
Ni-Fe alloyUsed as the corrosion resistant alloy Hastelloy.
Ni-Cr-Fe alloyUsed as the heat resistant and corrosion resistant alloy Inconel.

As a day-to-day application, the corrosion resistance of nickel is utilized in coins. In molds, nickel is used very often as films on the surfaces of molds in order to prevent gases or corrosive constituents being generated from molten plastics, cavity generation by adhered moisture, or to prevent corrosion of the core by oxidization.
In carbon steel, it is used as an alloy along with chromium (Cr), and is used widely as stainless steel for cavities, cores, and ejector pins, etc.
Since nickel is costlier than carbon steel, using it in the form of electroplated films or alloys can be said to be a rational method of use.