National Technical Reports Library - NTRL

National Technical Reports Library


Details
Actions:
Download PDFDownload XML
Download

Superplasticity in Selected Magnesium-Base Alloys.


PB80125875

Publication Date 1979
Personal Author Tilman, M. M.; Crosby, R. L.; Neumeier, L. A.
Page Count 26
Abstract Research was conducted by the Bureau of Mines to determine the potential for superplastic forming of magnesium-base alloys. The suitability of these alloys for superplastic forming may provide added incentive for the use of domestically available magnesium as a substitute for metals requiring imported raw materials. Commercial compositions of the alloys ZK60A (Mg-5.5Zn-0.45Zr) and AZ61A (Mg-6.5Al-1Zn) were melted, cast, and extruded to 3/8-inch diameter rod having average grain diameters of less than 10 micrometers. Tensile testing was conducted to delineate parameters of superplasticity at temperatures ranging from 270 to 330C and initial strain rates of 0.002 to 2.0/min. A maximum strain-rate sensitivity index of approximately 0.65 at 310C and 0.002/min strain rate was determined for AZ61A, which was not known previously to be superplastic. For 2K60A, calculations of experimentally derived data indicated a maximum strain-rate sensitivity index of approximately 0.45 at 310C between 0.04 and 0.1/min strain rate. Maximum elongations of over 680 pct and 700 pct were obtained for AZ61A and ZK60A, respectively. The potential for commercial superplastic forming would appear somewhat more favorable for ZK60A than for AZ61A, because ZK60A retains higher strengths after deformation than does AZ61A, and maximum superplasticity occurs at higher strain rates in ZK60A, which facilitates forming.
Keywords
  • Magnesium alloys
  • Metal working
  • Tensile properties
  • Microstructure
  • Ductility
  • Superplasticity
  • Magnesium alloy AZ-61-A
  • Magnesium alloy ZK-60-A
  • Superplastic forming
Source Agency
  • Bureau of Mines
NTIS Subject Category
  • 71N - Nonferrous Metals & Alloys
Corporate Authors Bureau of Mines, Rolla, MO. Rolla Metallurgy Research Center.
Document Type Technical Report
Title Note Rept. of investigations 1979.
NTIS Issue Number 198008
Superplasticity in Selected Magnesium-Base Alloys.
Superplasticity in Selected Magnesium-Base Alloys.
PB80125875

  • Magnesium alloys
  • Metal working
  • Tensile properties
  • Microstructure
  • Ductility
  • Superplasticity
  • Magnesium alloy AZ-61-A
  • Magnesium alloy ZK-60-A
  • Superplastic forming
  • Bureau of Mines
  • 71N - Nonferrous Metals & Alloys
Loading