US 2137282 A
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Patented Nov. 1938 UNITED" STATES- COPPER ALLOYS Franz R. Hensel and Earl I. Larsen, Indianapolis, Ind., assignors to P. R. Mallory & 00., Inc., Indianapolis, Ind., a corporation of Delaware No Drawing. Application August 12, 1938, Serial No. 224,498
This invention relates to copper alloys.
This case is a continuation in part of our copcnding application. S. N. 164,032, filed September 15, 1937.
An object of the invention is to improve the physical, chemical and electrical, characteristics of such alloys.
Other objects of the invention will be apparent from the following description, taken in connection with the appended claim.
The present invention comprises a combination of elements, methods of manufacture, and the product thereof, brought out and exemplified in the disclosure hereinafter set forth, the scope of iizhe invention being indicated in the appended cla m.
While a preferred embodiment of the invention is described herein, it is contemplated that considerable variation may be made in the method of ing of iron, cobalt and nickel 0.1 to Zirc ni m 1 0.05 to 5 Silicon 0.05 to 3 Copper balance Where high electrical conductivities are desired,
it is preferred to keep the proportion of iron group metal within an upper limit of 5%.
The alloys of the present invention may also contain small proportions, or even up to several percent, of zinc, tin, calcium, lithium, magnesium, phosphorus and silver. In some cases a part of the silicon may be replaced by beryllium.
The silicon combines-with the iron group metal or metals to form the silicide thereof and thereby imparts age-hardening characteristics to the alloy. I
The addition of zinconium inthis type of alloy not only imparts additional age-hardening characteristics, but also produces a material of corrosion resistance, high strength at elevated temperatures and superior fatigue and impact properties.
60 The alloys can be made according to standard alloying methods. A preferred method for introducing the zirconium is to prepare a hardener alloy containing a high percentage of zirconium and then introduce a predetermined amount of this alloy into a copper melt, containing the other ingredients in the desired proportions.
After the alloy has been prepared according to such methods, the material may be heat treated by first quenching the alloy in the form of a billet 00 or sand casting, or any other form, from above amount of silicon has a composition as follows:
700 C. and subsequently aging at a temperature below 700 C. In certain cases, we have found it also advisable to use one heat treatment only. namely, the low temperature treatment, and eliminate the quenching treatment.
If the materials are processed by rolling, extruding, drawing, forging or any other fabricating methods, we have found it desirable in many cases to quench the materials from the intermediate anneals, cold working same and applying an aging treatment afterwards. This cold working before aging hastens considerably the precipitation of the dispersed phase. In addition, a certain amount of cold work may be applied after aging in order to improve the surface finish of the wrought material.
An example of an alloy produced according to the present invention is:
Per cent Zirconium 0.70 a Cobalt 2.31 Silicon 0.73 Copper balance After quenching this alloy from 950 C. and aging at 450 C., a Rockwell B hardness of 89 was 25 obtained, with 45% electrical conductivity. After cold working such an alloy, a Rockwell B hardness of 95 was reached.
The hardness of this alloy after aging reaches 50 Rockwell B and the conductivity 43%. If cold work is applied after quenching, the maximum hardness after reduction is '77 Rockwell B. The material responds to cold working after complete heat treatment and the hardness is increasedfrom50 Rockwell B to '76 Rockwell B.
A nickel-containing alloy showing a larger 4i Per cent Zirnnnium 0,80 Nickel 1.96 Silicon Q Copper balance 50 The maximum hardness after quenching from 950 C., and aging at 450 C., was close to Rockwell B, with an electrical conductivity of 30%. Cold working again increased the ultimate hardness that could be reached with this composition.
The addition of zirconium has further beneficial effects, in so far as it raises the annealing temperature, and atth 'e same time provides a very o for. condenser tubing is as follows:
flne zrain structure, which is highly desirable it the material is to be worked into sheets, strips, or tubing.
The composition which has exceptional merits Per cent Nickel 15 to 30 Zflcmlum 0.05 to 5 Silicon 0.05 to 3 Copper balance While the present invention as to its objects and advantages has been described herein as carried out, in specific embodiments, it is not desired to order of 450 C.
FRANZ R. HENSEL. EARL I. LARSEN.