High strength aluminum hot stamping with intermediate quench

Abstract

A method of forming an aluminum alloy part is provided for enhanced formability. The method includes providing a 7xxx series aluminum alloy blank, heating the blank to at least its solvus temperature, and performing an intermediate quench on the blank to a temperature between about 200° C. to about 440° C. at a rate between about 100° C./s to about 500° C./s. The blank is transferred to a stamping die where a secondary quench and forming the blank into a part are carried out, where in one form, the steps of transferring the blank and performing the secondary quench and forming are completed within ten seconds or less. The part may then be optionally artificially aged for increased strength.

What is claimed is: 
     
         1 . A method of forming an aluminum alloy part comprising the steps of:
 providing a 7xxx series aluminum alloy blank;   heating the blank to at least its solvus temperature;   performing an intermediate quench of the blank to a temperature between about 200° C. to about 440° C. at a rate between about 100° C./s to about 500° C./s;   transferring the blank to a stamping die; and   simultaneously performing a secondary quench on the blank and forming the blank into a part,   wherein the steps of transferring the blank to the stamping die and performing the secondary quench and forming are completed within ten seconds or less.   
     
     
         2 . The method according to  claim 1 , wherein the blank is positioned between flat press plates for the intermediate quench. 
     
     
         3 . The method according to  claim 1 , wherein the secondary quench is performed to a temperature less than 80° C. in a cooled die. 
     
     
         4 . The method according to  claim 3  further comprising a step of artificial aging. 
     
     
         5 . The method according to  claim 4 , wherein the artificial aging is a PFHT (post forming heat treatment) at a temperature between about 180° C. and about 205° C. for about 30 minutes. 
     
     
         6 . The method according to  claim 1 , wherein the secondary quench is performed to a temperature between about 100° C. and about 200° C. in a heated die. 
     
     
         7 . The method according to  claim 6 , wherein the part is transferred to an elevated temperature enclosure for artificial aging after the secondary quench. 
     
     
         8 . The method according to  claim 7 , wherein the artificial aging is a PFHT (post forming heat treatment) at a temperature of about 205° C. for about 30 minutes. 
     
     
         9 . A part formed according to the method of  claim 1 . 
     
     
         10 . A vehicle having at least one part formed according to  claim 1 . 
     
     
         11 . A method of forming a part comprising:
 heating a 7xxx series aluminum alloy blank;   performing an intermediate quench of the blank to a temperature between about 200° C. to about 440° C.;   transferring the blank to a stamping die; and   performing a secondary quench and forming the blank into a part.   
     
     
         12 . The method according to  claim 11 , wherein the intermediate quench is performed at a rate between about 100° C./s to about 500° C./s. 
     
     
         13 . The method according to  claim 11 , wherein the secondary quench is performed to a temperature less than about 80° C. in a cooled die. 
     
     
         14 . The method according to  claim 11 , wherein the secondary quench is performed to a temperature between about 100° C. and about 200° C. 
     
     
         15 . The method according to  claim 11  further comprising a step of artificial aging after the secondary quench. 
     
     
         16 . The method according to  claim 11 , wherein the steps of transferring the blank and performing the secondary quench and forming are completed within ten seconds or less 
     
     
         17 . A method of forming an aluminum alloy part comprising the steps of:
 providing a 7xxx series aluminum alloy blank;   heating the blank to at least its solvus temperature;   performing an intermediate quench of the blank to a temperature between about 200° C. to about 440° C. at a rate between about 100° C./s to about 500° C./s;   transferring the blank to a stamping die;   simultaneously performing a secondary quench on the blank and forming the blank into a part,   wherein the steps of transferring the blank to the stamping die and performing the secondary quench and forming are completed within ten seconds or less; and   artificially aging the part.   
     
     
         18 . The method according to  claim 17 , wherein the artificial aging is a PFHT (post forming heat treatment) at a temperature between about 180° C. and about 205° C. for about 30 minutes. 
     
     
         19 . The method according to  claim 17 , wherein the secondary quench is performed to a temperature less than about 80° C. in a cooled die. 
     
     
         20 . The method according to  claim 17 , wherein the secondary quench is performed to a temperature between about 100° C. and about 200° C. in a heated die.