Classifications

• • 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
  • C22C9/05—Alloys based on copper with manganese as the next major constituent
• • 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

• Such alloys have become known in dilferent compositions, with higher or lower manganese contents, the higher manganese alloys having no zinc and/or almost no iron or nickel.
• Such alloys have become known which contain 2 to 4% of iron, 1 to 6% of nickel, 3.5 to 9.5% of aluminum, 15 to 35% of manganese, the balance copper and usual impurities.
• Such alloys have good mechanical characteristics and a good corrosion resistance, so that they have been proposed as material f.i. for the casting of ships propellers.
• This invention aims at obtaining a new alloy of the same kind but of difierent composition and having in part the same, in part better mechanical characteristics, corrosion resistance, castability, weldability and characteristics for easy extrusion in hot condition. Moreover this invention aims at obtaining an alloy of this kind which is easier to manufacture, particularly with respect to corrections to be made in the molten alloy, than such known alloys. This is obtained by giving such an alloy according to the invention a composition in which it contains: 1 to 8% of aluminum, 0 to 6% of nickel, 1 to of iron, 3 to 11% total of nickel and iron, more than 21 up to 35% of manganese and 1 to 7% of zinc, balance copper and usual impurities.
• manganese has a so-called aluminum equivalent, which means that part of the aluminum may be replaced by manganese.
• Such replacement has a double etfect, viz. on the one hand with respect to several mechanical characteristics and on the other hand with respect to the structure of the alloy and amounts of socalled zzand [St-phase in the alloy.
• manganese has the same aluminum equivalent, namely of about 0.1 to 0.2, which means that a change in the amount of manganese has a correspondingly smaller effect than a corresponding change in aluminum, but in the same direction.
• the aluminum content is highly critical both with respect to the mechanical characteristics and with respect to the structure. Thus during the manufacture of the molten alloy corrections of the bath by changing the aluminum content are difficult to realize and small unintended differences in the aluminum content give considerable difierences in characteristics.
• the present invention is thus also based upon the idea that it is possible to obtain more freedom in influencing the precipitation of the iron-rich phase or in keeping it at a sufiicient level and thus obtaining a very good corrosion resistance while being as free as possible in varying the mechanical properties by enabling a variation within relatively wide limits of the manganese content together with the zinc and aluminum contents.
• zinc has. about twice the influence of manganese on the mechanical properties and on the structure, particularly as to (X- and fi-phase, but as zinc has little influence on the precipitation of the iron-rich phase and as manganese and aluminum in certain fields have an opposite effect on this precipitation, the wide limits of the manganese content and the presence of zinc within the limits given by the invention make it possible to obtain the desired mechanical properties and 0c and 5- structure by choosing the desired value of the total aluminum equivalent, composed of the influences of aluminum, zinc and man-ganese, while nevertheless maintaining freedom to vary the aluminum and manganese contents mutually without varying said total aluminum equivalent by varying the zinc content to obtain the desired amount of precipitation of the iron-rich phase and thus full corrosion resistance. It thus appeared possible to vary the zinc content for this purpose up to high manganese contents, namely up to 35% of manganese.
• the surprising character of the present invention may appear from the fact that up to now in comparable alloys with relatively high manganese content no zinc was used at all, such as in the known alloy given above in the publication of the British Standards Institution: BS. 1400: 1961: Schedule of Copper Alloy Ingots and Copper Alloy Castings, pages to 68 for manganese-aluminumcopper alloys the total absence of zinc is taken as a basis.
• the total amount of iron and nickel is maintained from 3 to 11% as given above the corrosion resistance is most favourable.
• the manganese content is 28% or higher the aluminum content should be lower than 7% as the alloys otherwise could become too brittle.
• an alloy according to the invention so that it contains:
• an alloy which has a relatively high elongation and ductility it is preferable according to the invention to manufacture an alloy of the following composition:
• Example II In the same manner as given in, Example I an alloy was made which was harder with a high tensile strength and a moderate elongation, having the following composition:
• the invention can be realized by melting the components together in a metallurgical furnace in a manner generally known in the art.
• An alloy having the following weight composition: 1 to 8% aluminum, up to 6% nickel, 1 to 5% iron, more than 21 up to 35% manganese, 1 to 7% zinc, balance essentially copper, the sum of the iron and any nickel being 3 to 11%, the aluminum content being not more than 7% if the manganese content is as high as 28%, the aluminum equivalent, calculated by adding to the aluminum percentage 0.15 times the manganese percentage and 0.35 times the zinc percentage, being between 7 and 13.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Conductive Materials (AREA)
• Prevention Of Electric Corrosion (AREA)
• Lead Frames For Integrated Circuits (AREA)

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Cited By (4)

Citations (2)

• 1964
  • 1964-12-10 US US417473A patent/US3323913A/en not_active Expired - Lifetime
  • 1964-12-10 BE BE656919D patent/BE656919A/xx unknown
  • 1964-12-10 GB GB50341/64A patent/GB1040790A/en not_active Expired
  • 1964-12-11 ES ES0306986A patent/ES306986A1/es not_active Expired
  • 1964-12-12 DK DK612664AA patent/DK106468C/da active

Patent Citations (2)

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