Hot Deformation Processing of a Precipitation Hardening Powder Metal Alloy

Abstract

A method of forming a sintered and swaged powder metal component to be comparable as a substitute for wrought 6013 aluminium alloy. A powder metal composition is compacted to form a green compact in which the powder metal composition includes an aluminum base powder metal, an aluminum-silicon powder metal, an aluminum-copper powder metal, and an elemental magnesium powder metal. The green compact is sintered to form a sintered part. The sintered part is swaged to form a sintered and swaged powder metal component. This method can produce a sintered and swaged powder metal component that after a T8 treatment has mechanical properties approaching that of wrought 6013 aluminum alloy.

What is claimed is: 
     
         1 . A method of forming a sintered and swaged powder metal component to be comparable as a substitute for wrought 6013 aluminum alloy, the method comprising the steps of:
 compacting a powder metal composition to form a green compact, the powder metal composition including an aluminum base powder metal, an aluminum-silicon powder metal, an aluminum-copper powder metal, and an elemental magnesium powder metal;   sintering the green compact to form a sintered part; and   swaging the sintered part to form a sintered and swaged powder metal component.   
     
     
         2 . The method of  claim 1 , further comprising, after the step of swaging, the further steps of solutionizing, water quenching, and aging the sintered and swaged powder metal component. 
     
     
         3 . The method of  claim 2 , wherein the step of solutionizing occurs in air at between 540° C. and 580° C. 
     
     
         4 . The method of  claim 3 , wherein the step of solutionizing occurs in air more narrowly at between 550° C. and 570° C. 
     
     
         5 . The method of  claim 4 , wherein the step of solutionizing occurs in air at 560° C. 
     
     
         6 . The method of  claim 2 , wherein the step of solutionizing occurs for between 1.5 hours and 2.5 hours. 
     
     
         7 . The method of  claim 6 , wherein the step of solutionizing occurs for 2 hours. 
     
     
         8 . The method of  claim 2 , wherein the step of aging occurs at between 180° C. and 200° C. 
     
     
         9 . The method of  claim 8 , wherein the step of aging occurs at 190° C. 
     
     
         10 . The method of  claim 8 , wherein the step of aging occurs for between 1 hour and 8 hours. 
     
     
         11 . The method of  claim 10 , wherein the step of aging occurs for 5 hours. 
     
     
         12 . The method of  claim 2 , wherein the hardness of the sintered and swaged powder metal component is in a range of 65-76 HRB. 
     
     
         13 . The method of  claim 12 , wherein the hardness of the sintered and swaged powder metal component is more narrowly in a range of 70-76 HRB. 
     
     
         14 . The method of  claim 2 , wherein the sintered and swaged powder metal component, as sintered and subjected to a T6 treatment has a Young's modulus of between 43 GPa and 100 GPa, a Yield Strength of between 344 MPa and 375 MPa, and an ultimate tensile strength (UTS) between 390 MPa and 419 MPa. 
     
     
         15 . The method of  claim 2 , wherein the sintered and swaged powder metal component, as sintered and subjected to a T8 treatment has a Young's modulus of between 68 GPa and 73 GPa, a Yield Strength of between 397 MPa and 416 MPa, and an ultimate tensile strength (UTS) between 406 MPa and 433 MPa. 
     
     
         16 . The method of  claim 15 , wherein the sintered and swaged powder metal component has a ductility of between 2.8% and 8%. 
     
     
         17 . The method of  claim 1 , further comprising, after the step of swaging, the further steps of solutionizing at between 540° C. and 580° C., water quenching, and aging at between 180° C. and 200° C. the sintered and swaged powder metal component. 
     
     
         18 . The method of  claim 1 , wherein a swaged density of sintered and swaged powder metal component is between 99% and 100% of theoretical density of the sintered and swaged powder metal component. 
     
     
         19 . The method of  claim 1 , wherein a swaged density of sintered and swaged powder metal component is between 99.1% and 99.5% of theoretical density of the sintered and swaged powder metal component. 
     
     
         20 . The method of  claim 1 , wherein a weight percent of silicon in the powder metal composition is in a range of 0.6 to 1.0 wt % of the powder metal composition, a weight percent of copper in the powder metal composition is in a range of 0.7 to 1.1 wt % of the powder metal composition, and a weight percent of magnesium in the powder metal composition is in a range of 0.8 to 1.2 wt % of the powder metal composition. 
     
     
         21 . The method of  claim 20 , wherein the aluminum base powder metal is an aluminum powder metal pre-alloyed with manganese to provide a weight percent of manganese in the powder metal composition is in a range of 0.2 to 1.2 wt % of the powder metal composition. 
     
     
         22 . The method of  claim 21 , wherein the weight percent of manganese in the powder metal composition is more narrowly in a range of 0.4 to 0.6 wt % of the powder metal composition. 
     
     
         23 . The method of  claim 22 , wherein the weight percent of manganese in the powder metal composition is 0.5 wt % of the powder metal composition. 
     
     
         24 . The method of  claim 20 , wherein the aluminum base powder metal is pure aluminum with no effective alloying elements pre-alloyed in the aluminum base powder metal. 
     
     
         25 . The method of  claim 20 , wherein the powder metal composition further comprises an elemental tin powder metal and a weight percent of tin in the powder metal composition is less than 1.0 wt % of the powder metal composition. 
     
     
         26 . A sintered and swaged powder metal component made according to the method of  claim 1 .