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US 4,731,129 AGranted
Superplastic zinc/aluminum alloy
AssigneeBNF Metals Technology Centre
InventorCharles G. Purnell
Life of this patent
Estimating the term…
Abstract
A zinc/aluminum alloy feedstock containing 18-30% by weight Al, 0.003-0.2% by wt. Mg, 0.5-2.5% by wt. Cu, 0.02-0.5% by wt. Fe, 0-0.1% by wt. Si, Zn balance (including any impurities) is capable of achieving high plasticity at temperatures of 240.degree. C. or above after being subjected to a multistage heat treatment including an extrusion step.
Claims7
A method of making an alloy capable of being superplastically deformed which method comprises
- (1) heating an alloy having the following composition
- ______________________________________ content, % by weight ______________________________________ Al 18-30 Mg 0.003-0.2 Cu 0.5-2.5 Fe 0.02-0.5 Si 0-0.1 Zn balance ______________________________________
- at a temperature greater than 275.degree. C. but below solidus until homogeneity of the high temperature zinc/aluminum matrix is substantially obtained;
- (2) quenching the alloy;
- (3) extruding the alloy at a temperature of from 150.degree. to 225.degree. C.;
- and
- (4) as a separate stage, either before or after the extrusion step (3), annealing the alloy at a temperature of from 200.degree. to 250.degree. C. for at least one hour.
4 more elements
A method of making a superplastic alloy which method comprises
- (1) heating an alloy based on the zinc/aluminum eutectoid with additions of magnesium and copper and containing 0.14% by weight of iron and 0.025% by weight of silicon at about 350.degree. C. for about 20 hours;
- (2) quenching the alloy into water at room temperature;
- (3) preheating the alloy to a temperature of from 150.degree. to 200.degree. C.;
- (4) extruding the alloy at the same temperature as used in step (3);
- and
- (5) annealing the extruded alloy at about 220.degree. C. for about 2 hours.
3 more elements
A method of making a superplastic alloy which method comprises
- (1) heating an alloy having the following composition
- ______________________________________ content, % by weight ______________________________________ Al 25-28 Mg 0.003-0.2 Cu 0.5-2.5 Fe 0.02-0.15 Si 0-0.15 Pb up to 0.005, as impurity Cd up to 0.004, as impurity Sn up to 0.003, as impurity Zn balance ______________________________________
- at about 350.degree. C. for about 20 hours;
- (2) quenching the alloy into water at room temperature;
- (3) annealing the alloy at about 220.degree. C. for about 2 hours;
- and
- (4) extruding the alloy at a temperature in the range of from 150.degree. to 200.degree. C.
4 more elements
A two-phase alloy consisting of
- ______________________________________ content, % by weight ______________________________________ Al 18-30 Mg 0.003-0.2 Cu 0.5-2.5 Fe 0.02-0.5 Si 0-0.1 Zn balance (including impurities) ______________________________________
- which alloy is superplastic at a temperature of 240.degree. C. or above at a strain rate greater than 1 sec.sup.-1.
Dependencies are inferred from the claim text.