National Technical Reports Library

The National Technical Information Service acquires, indexes, abstracts, and archives the largest collection of U.S. government-sponsored technical reports in existence. The NTRL offers online, free and open access to these authenticated government technical reports. Technical reports and documents in its repository may be available online for free either from the issuing federal agency, the U.S. Government Publishing Office’s Federal Digital System website, or through search engines.

Details

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

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