Deformed aluminum alloy casting and method of manufacturing the same

Abstract

Provided are a deformed Al alloy casting with improved formability by local heat treatment, and a method of manufacturing the same, and the method includes a casting step for forming an Al alloy casting by casting molten metal formed by melting alloying elements of Al alloy, a solid solution treatment step for solid solution-treating the Al alloy casting, an aging step for aging the solid solution-treated Al alloy casting, a local heat treatment step for locally heat-treating a deformation target area of the aged Al alloy casting, and a deformation step for deforming the locally heat-treated deformation target area of the Al alloy casting.

What is claimed is: 
     
         1 . A method of manufacturing a deformed aluminum (Al) alloy casting, the method comprising:
 a casting step for forming an Al alloy casting by casting molten metal formed by melting alloying elements of Al alloy;   a solid solution treatment step for solid solution-treating the Al alloy casting;   an aging step for aging the solid solution-treated Al alloy casting;   a local heat treatment step for locally heat-treating a deformation target area of the aged Al alloy casting; and   a deformation step for deforming the locally heat-treated deformation target area of the Al alloy casting.   
     
     
         2 . The method of  claim 1 , wherein the solid solution treatment step is performed at a temperature ranging from 420° C. to 540° C. for 30 minutes to 8 hours. 
     
     
         3 . The method of  claim 1 , wherein the aging step is performed at a temperature ranging from 100° C. to 200° C. for 5 hours to 30 hours. 
     
     
         4 . The method of  claim 1 , wherein the local heat treatment step is performed at a temperature ranging from 300° C. to 450° C. for 30 seconds to 60 minutes. 
     
     
         5 . The method of  claim 1 , wherein, in the local heat treatment step, a non-deformation area other than the deformation target area is maintained at a temperature ranging from 20° C. to 200° C. 
     
     
         6 . The method of  claim 1 , wherein the deformation step is performed by swaging the deformation target area. 
     
     
         7 . The method of  claim 6 , wherein the swaging is performed by rotating a swaging tool at a speed ranging from 800 RPM to 1200 RPM, maintaining pressure for a time ranging from 0.1 second to 1 second, and lowering the swaging tool at a speed ranging from 0.4 mm/s to 0.8 mm/s. 
     
     
         8 . The method of  claim 1 , wherein the deformed Al alloy casting comprises at least one of AC1B alloy, AC2A alloy, AC2B alloy, AC3A alloy, AC4A alloy, AC4C alloy, AC4CH alloy, AC4B alloy, AC4D alloy, AC7A alloy, AC8A alloy, AC8B alloy, AC8C alloy, AC9A alloy, and AC9B alloy. 
     
     
         9 . The method of  claim 1 , wherein the deformed Al alloy casting comprises 6 wt % to 10 wt % of silicon (Si), 0.2 wt % to 0.5 wt % of magnesium (Mg), and a balance of Al and unavoidable impurities. 
     
     
         10 . The method of  claim 9 , wherein the deformed Al alloy casting further comprises at least one of more than 0 wt % and not more than 0.2 wt % of copper (Cu), more than 0 wt % and not more than 0.3 wt % of zinc (Zn), more than 0 wt % and not more than 0.5 wt % of iron (Fe), more than 0 wt % and not more than 0.6 wt % of manganese (Mn), more than 0 wt % and not more than 0.2 wt % of titanium (Ti), and more than 0 wt % and not more than 0.05 wt % of chromium (Cr). 
     
     
         11 . A deformed aluminum (Al) alloy casting manufactured using the method of  claim 1 . 
     
     
         12 . The deformed Al alloy casting of  claim 11 , wherein the deformed Al alloy casting has an average secondary dendrite arm spacing (SDAS) of 35 μm or less. 
     
     
         13 . The deformed Al alloy casting of  claim 11 , wherein the deformed Al alloy casting comprises eutectic silicon (Si) having an average particle diameter ranging from 8 μm to 12 μm. 
     
     
         14 . The deformed Al alloy casting of  claim 11 , wherein the deformed Al alloy casting has a hardness ranging from 50 HB to 70 HB. 
     
     
         15 . The deformed Al alloy casting of  claim 11 , wherein the deformed Al alloy casting satisfies a yield strength (YS) of 220 MPa or more, an ultimate tensile strength (UTS) of 300 MPa or more, and an elongation (EL) of 6% or more.