Deoxidized Copper
The following is a statement by the Bridgeport Deoxidized Metal Company in regard to their processes with copper: Deoxidized copper is Calumet and Hecla Lake copper, the purest and best copper in the world, from which the suboxide of the copper and the oxygen has been removed by our processes--thereby rendering the copper denser, stronger, tougher, and purer; enabling us to make solid castings of deoxidized copper 20 per cent denser, 35 per cent stronger, 50 per cent tougher, and 5 per cent better conductivity than the same copper not deoxidized, as per certificates and testimonies following:
Comparative analyses made at School of Mines, New York, of Calumet and Hecla Lake copper, with the same copper deoxidized:
CALUMET AND HECLA LAKE COPPER.
Constituents. No. 1 2. 3. Metallic copper..... 99.854 99.63 98.10 Suboxide of copper..... 0.293 0.324 1.95 Iron..... 0.015 0.011 .... Tin..... 0.021 .... .... Silver..... 0.012 0.024 0.03 Phosphorus..... trace .... trace Arsenic, nickel, zinc, lead, antimony, sulphur--none. DEOXIDIZED LAKE COPPER.
Constituents. Metallic copper..... 99.80 Suboxide of copper..... 0.07 Iron..... 0.01 Tin..... 0.01 Silver.... 0.02 Arsenic, lead, phosphorus, antimony, sulphur, aluminum, zinc, nickel, cobalt--none.
MEAN OF THE ANALYSES OF LAKE COPPER.
Metallic copper..... 99.19 Suboxide..... .85 DEOXIDIZED COPPER.
Metallic copper..... 99.89 Suboxide..... .07 Taking the mean of the results of tests by tension, the deoxidized bronze shows a superiority of 65.8 per cent in tensile strength and 58 per cent in elastic limit over the Navy Yard bronzes, with 53 per cent less elongation and 36 per cent less reduction of area.
All the Navy Yard bronzes when fractured showed large crystals of both copper and tin. The specimens from the Deoxidized Metal Company, on the contrary, show in fracture a very fine, even grain of lavender color, and were fine specimens of castings.
Short sections of tensile specimens have been forwarded by express to the bureau, which will show the appearance of the fractures in both the deoxidized and Navy Yard bronzes.
TESTS BY COMPRESSION.
The deoxidized specimens showed a superiority over the other bronzes of 60 per cent in strength and 23 per cent in elastic limit.
All specimens broke by triple flexure.
Deoxidized bronze as furnished for the above tests is remarkably close grained and homogeneous. It turns well in the lathe and is susceptible of high polish. It does not tarnish by exposure to the atmosphere as readily as the other bronzes tested, all of which have been exposed to like conditions since July 14th of this year, the deoxidized specimens being still intact, while the others are perceptibly tarnished. See COPPER.