Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper

Definitions

• This invention relates to copper base alloys and more particularly to ternary alloys containing copper, zirconium and arsenic.
• the principal object of the invention is to provide copper base alloys of the copper-zirconium type having improved properties and characteristics for applications requiring high electrical conductivity and good strength properties.
• the aforesaid advantages and benefits are attributable mainly to the combining of arsenic with zirconium to form finely dispersed particles throughout the crystal structure of the ternary alloy.
• the grain refinement effect of arsenic is such that the use of up to as much as 1% zirconium in the alloy presents no problems or difiiculties in connection with casting of the material and its subsequent processing for development of the superior properties of the alloys.
• the alloys of the present invention are characterized by the fact that they contain from 0.2 to 1% by weight of zirconium, from 0.1 to 0.5% by weight of arsenic, the balance being copper with its incidental impurities. It is generally preferred, however, to use from 0.3% to 0.7% zirconium and from 0.15 .to 0.35% arsenic with best results being obtained when the alloy contains about 0.5% zirconium and about 0.25% arsenic, balance copper.
• the ratio of zirconium to arsenic should generally be within the range of from 4:1 respectively to about 1.5:1 and preferably about 2:1 so that, after combining of the arsenic to form the ZrAs intermetallic compound, sufficient residual zirconium is made available for forming the also essential Cu Zr phase.
• the copper base used in making the alloy should preferably be oxygen free when the alloying ingredients are added to the copper melt. pers give better results than do oxygen-containing material such as tough pitch copper. Best results are obtained, however, with copper which is substantially oxy gen-free without requiring treatment with any of the conventional chemical deoxidants.
• Cathode copper, copper produced in a reducing atmosphere such as OFHC brand copper, in an inert atmosphere, under charcoal cover or in a vacuum are examples of the preferred initially oxygen-free copper base material.
• the alloys of the present invention are made following conventional alloying practices utilizing a protective gas cover during melting of the copper, alloying and casting operations.
• the copper is first melted under argon or other suitable protective gas cover in an alloying furnace such as an Ajax induction furnace using a graphite crucible.
• the alloying ingredients are added either successively or simultaneously using appropriate amounts of zirconium and arsenic in any suitable form for alloying purposes.
• Zirconium and arsenic as metal, sponge or powder and as master alloys of the respective elements with copper are illustrative of some of the materials that may be used in making the ternary alloys of the present invention.
• the melt is stirred, held at temperature for a few minutes following which the alloy is cast into graphite or any other suitable molds.
• arsenic as an alloying element contributes significantly to facilitating the production of uniformly sound castings despite zirconium contents of the alloy appreciably in excess of 0.15% which usually causes inverse segregation particularly in the larger size castings.
• arsenic in the amounts hereinbefore specified, no difficulties are encountered in producing sound castings notwithstanding a content of up to 1% zirconium in the cast material. Utilization of the zirconium and arsenic is virtually complete with little or no loss of alloying ingredients whereas considerable losses of zirconium are encountered in the production of the binary copperzirconium alloys despite the use of initially oxygen-free copper.
• the enhanced utilization of the alloying ingredients not only reduces losses of the alloying ingredients but enables much more elfective control of the alloying process whereby variations in the resulting alloy compositions can be minimized.
• the alloy nominally contains 0.5% zirconium, 0.25 arsenic, balance initially oxygen-free copper, approximately one half. of the zirconium combines with the arsenic to form a dispersed phase of Zr-As fine particles, the residual zirconium combining with the copper toform the Cu Zr phase.
• both of these phases are essential for developing the optimum properties of the alloys comprising the present invention.
• the heat treatment time may be varied as from about minutes to an hour or so depending upon the size or thickness of the specimen being treated as well as the temperature actually used. Contrasted with the requirement of a solution annealing temperature of about 980 C. for the binary alloys of-copper-zirconium, it is an important advantage of the alloys of this invention that solution annealing can be efiectively achieved at a substantially lower temperature.
• the marked grain refinement attributable to the arsenic content of the new alloy compositions may best be illustrated by comparison of solution annealed specimens of the alloy with and without arsenic but otherwise similar in all respects.
• specimens of Cu0.5% Zr alloy cold drawn to 0.4132" wire (with 72% reduction in area) and then solution annealed at different temperatures of 800, 850 and 900 C. for 30 minutes were characterized by an average grain size of 0.02, 0.035 and 0.045 mm. respectively.
• the arsenic-containing alloy consisting of 0.5 zirconium, 0.28% arsenic, balance copper subjected to the same treatment resulted in average grain sizes of 0.005, 0.008 and 0.01 mm. for the specimens annealed at 800, 850 and 900 C. respectively.
• the combination of properties possessed bythe copper-zirconium-arsenic alloys comprising the present invention are superior to any of the heretofore available alloys of the copper-zirconium type including the aforeunentionsd copper-zirconium-phosphorus alloys with or without iron, silicon, etc.
• the arsenic-containing alloys additionally possess good scale adherence qualities male, ing the material suitable for, applications in which free oxide scaling is objectionable.
• the copper-zirconium-arsenic alloys herein described are amenable to extensive hot and/or cold working up to reductions of or more with no difliculty. Aging may be carried at temperatures of from 350 to about 475" C. for varying periods of time ranging from 10 minutes to 2 hours depending on the size or thickness of the material being treated. Preferred practice consists of aging the material at about 400 C. for a period of approximately one hour.
• the binary copper-zirconium alloys are known to .re-. tain their properties at relatively high temperatures.
• specimens of representative alloys containing 0.5 Zr, balance Cu and 0.5% Zr, 0.25% As, balance Cu were tested at 400 C., the material being'first treatedas follows: (a) solution annealed at-900 C. for 30 minutes, (b) quenched, (0) cold rolled to 0.388" diameter rod with 53% reduction in area, and (d) aged at 375 C. for one hour.
• the high temperature properties measured at 400 C. are summarized in Table II.
• An alloy of copper, zirconium and arsenic which consists of from 0.2 to 1% by Weight of zirconium, from 0.1 to 0.5% by weight of arsenic, balance copper with normally associated incidental impurities.
• An alloy of copper, zirconium and arsenic which consists of from 0.2 to 1% by weight of zirconium, from 0.15 to 0.5 by weight of arsenic, balance copper, said copper being initially oxygen-free copper prior to its being alloyed with said zirconium and arsenic.
• An alloy of copper, zirconium and arsenic which 6 consists of firom 0.2 to 1% by weight of zirconium, 0.15 to 0.5 by weight of arsenic, balance copper, said cop per being initially chemically deoxidized copper prior to its being alloyed with said zirconium and arsenic.
• An alloy of copper, zirconium and arsenic which consists of from 0.2 to 1% by weight of zirconium, 0J1 to 0.5% by weight of arsenic, balance copper, said zirconium and arsenic respectively being present on a weight basis in the ratio of from 4:1 to 1.5: 1.
• An alloy of copper, zirconium and arsenic which consists of from 0.3 to 0.7% by Weight of zirconium, from 0.15 to 0.35% by weight of arsenic, balance initially oxygen-free. copper, said zirconium and arsenic respectively being present on a weight basis in the ratio of at least 2:1.
• An alloy of copper, zirconium and arsenic which consists of about 0.5% by weight of zirconium, about 0.25% by weight of arsenic, balance initially oxygenfree copper with incidental impurities.

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• 1961
  • 1961-11-06 US US150162A patent/US3107998A/en not_active Expired - Lifetime
• 1962
  • 1962-07-10 GB GB26465/62A patent/GB996027A/en not_active Expired
  • 1962-07-26 FI FI621417A patent/FI41324C/fi active
  • 1962-08-06 CH CH937362A patent/CH405721A/fr unknown
  • 1962-09-20 DE DEA41193A patent/DE1294026B/de active Pending

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