Method for manufacturing 6xxx alloy materials for vacuum chambers

Abstract

The invention relates to a manufacturing process for an aluminum block of at least 250 mm thick designed for the manufacture of elements for vacuum chambers in which the following operations are carried out successively: an alloy block is cast by semi-continuous casting, the composition of this block in weight % being: Si 0.5-1.5; Mg: 0.5-1.5; Fe<0.3; Cu<0.2; Mn<0.8; Cr<0.10; Ti<0.15, other elements <0.05 each and <0.15 in total, the rest aluminum; solution heat treatment is performed at a temperature ranging between 450 and 560° C. directly on the cast block and optionally homogenized; the block that has undergone solution heat treatment is quenched at a cooling speed between the solution heat treatment temperature and 200° C. of at least 200° C./h; the block quenched and optionally stress-relieved is artificially aged. The blocks obtained in this way are advantageous for the production of vacuum chambers for the manufacture of integrated electronic circuits containing semiconductors, flat screens and/or photovoltaic panels.

1 . A Manufacturing process for a block of aluminum at least 250 mm thick designed for manufacture of an element for a vacuum chamber, said process comprising successively:
 (a) casting an alloy block with a composition in weight % Si: 0.5-1.5, Mg: 0.5-1.5; Fe<0.3; Cu<0.2; Mn<0.8; Cr<0.10; Ti<0.15, other elements <0.05 each and <0.15 in total, the rest aluminum by semi-continuous casting;   (b) optionally, homogenizing the cast block at a temperature ranging from 500° C. to 590° C.;   (c) performing solution heat treatment at a temperature ranging from 450 to 560° C. directly on the cast and optionally homogenized block; without carrying out before solution heat treatment a hot or cold working step;   (d) quenching the block that has undergone solution heat treatment between the solution heat treatment temperature and 200° C. at a cooling speed of at least 200° C./h;   (e) optionally stress-relieving the block quenched in this way;   (f) artificially aging the block quenched and optionally stress-relieved.   
     
     
         2 . The process according to  claim 1 , wherein the manganese content is lower than 0.6 wt. % and optionally lower than 0.05 wt. % 
     
     
         3 . The process according to  claim 1 , wherein the chromium content is lower than 0.05 wt. % and optionally lower than 0.03 wt. %. 
     
     
         4 . The process according to  claim 1 , wherein the Cr, Mn and Zr contents are simultaneously lower than 0.05 wt. % and optionally lower than 0.03 wt. %. 
     
     
         5 . The process according to  claim 1 , wherein the iron content is at least 0.1 wt. %. 
     
     
         6 . The process according to  claim 1 , wherein the silicon content is from 0.5 to 0.8 wt. % and the magnesium content is from 0.8 to 1.2 wt. %. 
     
     
         7 . The process according to  claim 1  wherein the silicon content is from 0.8 to 1.2 wt. % and the magnesium content is from 0.6 to 1.0 wt. %. 
     
     
         8 . The process according to  claim 7 , wherein the silicon content ranges from 0.8 to 1 wt. % and optionally from 0.85 to 0.95 wt. %, and said magnesium content ranges from 0.6 to 0.8 wt. % and optionally from 0.65 0.75 wt. %. 
     
     
         9 . The process according to  claim 1 , wherein said cooling speed from the temperature of solution heat treatment to 200° C. lies from 200° C./h to 400° C./h. 
     
     
         10 . The process according to  claim 1 , wherein said cooling speed from the temperature of solution heat treatment to 200° C. is at least 800° C./h. 
     
     
         11 . The process according to  claim 1 , wherein stress-relieving is carried out by cold compression with permanent set ranging from 1% to 5%. 
     
     
         12 . A block comprising in weight %: Si: 0.5-1.5, Mg: 0.5-1.5; Fe<0.3; Cu<0.2; Mn<0.8; Cr<0.10; Ti<0.15, other elements <0.05 each and <0.15 in total, the rest aluminum, said block being at least 250 mm thick, and, in T6 or T652 temper, with a ultimate tensile strength Rm at ¼ thickness of at least 280 MPa and an tensile yield strength Rp0.2 at ¼ thickness of at least 240 MPa, obtained by semi-continuous casting, optionally homogenizing at a temperature ranging from 500° C. to 590° C., solution heat treating at a temperature ranging from 450° C. to 560° C. directly on a cast and optionally homogenized block, without carrying out before solution heat treatment a hot or cold working step, quenching with a cooling speed from the solution heat treatment temperature to 200° C. of at least 200° C./h, optionally stress-relieving and artificial aging. 
     
     
         13 . Block obtained by the process according to of  claim 1 . 
     
     
         14 . The block according to  claim 12 , wherein the composition is, in weight %, Si: 0.5-1.2; Mg: 0.6-1.0; Fe 0.1-0.3; Cu<0.2; Mn<0.05; Cr<0.05; Ti<0.15; other elements <0.05 each and <0.15 in total, and in that in temper T6 or T652 said block comprises an ultimate tensile strength Rm at ¼ thickness of at least 300 MPa and a tensile yield strength Rp0.2 at ¼ thickness of at least 270 MPa. 
     
     
         15 . The block according to  claim 12 , capable of being used in producing a vacuum chamber for manufacture of an integrated electronic circuit containing a semiconductor, a flat screen and/or a photovoltaic panel. 
     
     
         16 . The process according to  claim 2 , wherein the chromium content is lower than 0.05 wt. % and optionally lower than 0.03 wt. %. 
     
     
         17 . The block according to  claim 13 , wherein the composition is, in weight %, Si: 0.5-1.2; Mg: 0.6-1.0; Fe 0.1-0.3; Cu<0.2; Mn<0.05; Cr<0.05; Ti<0.15; other elements <0.05 each and <0.15 in total, and in that in temper T6 or T652 the block has an ultimate tensile strength Rm at ¼ thickness of at least 300 MPa and a tensile yield strength Rp0.2 at ¼ thickness of at least 270 MPa.