Nickel S-rounds for electroforming nickel structures

Nickel
S-rounds

Electroforming Department

ELECTROFORMING
DEPARTMENT

Nickel Metal

    Optiforms specializes in manufacturing nickel electroformed optics. All of our electroformed reflectors are composed of nickel (Ni), a lustrous metal with a silvery-white and slightly golden tinge. Nickel has an atomic number of 28 and has the ability to take a high polish. Nickel is one of only four metals that is ferromagnetic at room temperature, the others being iron, cobalt, gadolinium.

     Historically nickel has been used for coinage and touching up metals like iron and brass. Today nickel is used in many different products including stainless steel, magnets, batteries, and of course nickel electroformed optics. In the past nickel was commonly mistaken for silver ore. The unintentional use of nickel dates back to 3500BC. Ancient bronzes from Syria have been found to contain 2% nickel and Chinese manuscripts dating from 1400BC call this metal "white copper." Medieval Germans mined a red ore that they mistakenly thought was copper. The miners were unable to extract copper from the ore and blamed a mischievous sprite named "nickel" for the problem.

     Nickel was discovered in 1751 by Baron Axel Fredrik Cronstedt. He was attempting to extract copper from ore but extracted a silvery white metal that he named after the sprite "nickel", common to German mythology. In modern German, kupfernickel designates the alloy cupronickel.

     Nickel is extracted from its ore using conventional roasting and reduction processes which yield a metal of 75% purity. The final purification of nickel oxides is performed using the Mond process. The Mond process increases the nickel to 99.9% purity by reacting carbon monoxide with nickel to form a volatile nickel compound known as nickel carbonyl. Impurities remain solid and nickel carbonyl gas passes into a large chamber where it decomposes and is stirred into nickel spheres. This process produces highly pure nickel. Another form of nickel refinement is used to collect nickel, this second process involves electrolytically collecting the nickel metal from a solution and plating it onto a cathode. This produces a 75% pure grade nickel which is typically acceptable for many applications however this grade is not acceptable for Optiforms reflective optics.

    Optiforms uses nickel anodes to manufacture its electroformed optics. A nickel purity of 99.9%, these S-round anodes allow optiforms to plate faster. Here is a chart that has many of the properties of nickel.



Properties 
Crystal StructureFace-centered Cubic
Magnetic OrderingFerromagnetic
Electrical Resistivity(20 °C) 69.3 nΩ-m
Thermal Conductivity(300 K) 90.9 W⋅m-1⋅K-1
Thermal Expansion(25 °C) 13.4 μm⋅m-1⋅K-1
Speed of sound (thin rod) (r.t) 4900 m.s-1
Youngs Modulus200GPa
Shear Modulus180 GPa
Bulk Modulus0.31
Poissin Ratio4
Mohs Hardness638MPa
Vickers Hardness700MPa
Brinnell Hardness7440-02-0