Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/003—Alloys based on aluminium containing at least 2.6% of one or more of the elements: tin, lead, antimony, bismuth, cadmium, and titanium
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C21/00—Alloys based on aluminium
  • C22C21/10—Alloys based on aluminium with zinc as the next major constituent

Definitions

• die container temperature was 800 F.
• the extrusion was quenched by an air blast at the die, and the extrusion ram speed was held at 33 feet/ minute.
• Zinc-magnesium alloy representative of the invention con-
• An aluminum-base alloy system consisting essentially a d Zinc, magnesium, 05% lead, 05% of aluminum, zinc and magnesium has been developed bismuth, and the balance aluminum except for less than heretofore but has not exhibited suitable extrudability 1% impurities consisting primarily of iron and silicon. and machinability to justify its use as machine screw stock the pri r art aluminum-copper alloy contained 5.5% copor the like.
• extrudability is indicated by the breaking pressure required to initiate extrusion at a specified billet temperature, lower breaking pressure representing better extrudability.
• Each of the alloys contained less than 1% impurities consisting primarily of iron and silicon.
• bookmold billets of the alloys 3% inches in diameter were homogenized by holding them at 815-865 F. for about 12 hours. After cutting each billet to an 11 inch length, one billet of each composition was extruded at each of two temperature levels (825 F. and 875 F.) to 7 inch rod.
• the preheat time for each extrusion was 2 hours at temperature and the From the data of Table II it is apparent that the alloy of the invention attained substantially its ultimate tensile strength (U.T.S.), yield strength (Y.S.), elongation and reduction of area (R. of A.) merely by air quenching at the extrusion die, whereas both of the prior art alloy systems required solution heat treatment to develop these properties to comparable levels.
• a solution heat treatment is not required by the alloys of the invention because of their lower critical cooling rate compared to those of the prior art alloys.
• the alloys of the invention advantageously have a TABLE III Property Condition Al-Mg-Zn Al-Cu Al-Mg-Si Alloy Al y Alloy U.T.S. (K s.i.) ⁇ Quenehed at die and 21% drawn 48. 1 39. 6 28. 1 Solution heat treated and 21% drawn 45. 1 49.4 36. 8 Y.S. (K s.i.) " ⁇ Quenched at die and 21% drawn 41. 3 34. 1 26. 4 Solution heat treated and 21% drawn 37. 8 42. 9 33. 1 Elong. (percent) [Quenched at die and 21% drawn 14. 3 9. 2 13. 0 [Solution heat treated and 21% drawn 14. 8 9. 2 13.0 R. 01A. (percent) ⁇ Quenched at die and 21% drawn 58. O 38. 4 58. 6 Solution heat treated and 21% drawn. 55. 4 36. 3 54.8
• the ease of extrudability of the alloy of the invention compares favorably with or exceeds that of the aforementioned prior art alloys as demonstrated by the breaking pressure data reported in Table IV. For each alloy there is given the average value of a number of tests for the breaking pressure required to initiate extrusion. From this data it can be seen that the alloy of the invention had a better extrudability than the prior art aluminumcopper alloy and was comparable with the prior art alu minum-magnesiurn-silicon alloy. Thus, the alloy of the invention can be extruded at least as fast as the aluminummagnesium-silicon system alloy and faster than the aluminum-copper system alloy.
• each of copper and manganese increases the strength of the alloys, and up to about 0.5% by Weight of chromium serves as a grain growth inhibitor or refiner as well as to inhibit stress corrosion.
• Iron and silicon are generally indigenous impurities and can be tolerated up to a total of about 1% by weight with no significant effect upon the desirable and novel combination of properties of the alloys of the invention.
• An extrudable free machining aluminum base alloy consisting essentially of about 2 to 5.5% zinc, about 0.25 to 2.5% magnesium, about 0.3 to 2.5% bismuth or lead or both, and the balance aluminum.
• An extrudable free machining aluminum base alloy consisting essentially of about 3.8% zinc, 1.1% magnesium, 0.5% lead, 0.5 bismuth, and the balance aluminum.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Extrusion Of Metal (AREA)
• Forging (AREA)

Priority Applications (3)

Applications Claiming Priority (1)

Publications (1)

Family

ID=24205010

Family Applications (1)

Country Status (3)

Cited By (2)

Citations (4)

• 1966
  • 1966-04-26 US US552363A patent/US3414407A/en not_active Expired - Lifetime
• 1967
  • 1967-04-19 DE DE19671608203 patent/DE1608203B2/de active Pending
  • 1967-04-24 GB GB08677/67A patent/GB1176235A/en not_active Expired

Patent Citations (4)

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