An aluminum alloy and the preparation process thereof

Abstract

The present invention relates to an aluminium alloy and a process of producing the same, wherein the aluminium alloy comprises Al, Si, Fe, Mg, Cu, Ti and optionally other impurities, characterized in that the components are comprised in amounts by weight of: Si: 0.04-0.1%, Fe: 0.2-0.4%, Mg: 0.055-0.12%, Cu: 0.004-0.01%, Ti: 0.003-0.02%; any one of the other impurities is in an amount by weight of no more than 0.03%; and the balance is Al. The present invention also relates an article comprising the aluminium alloy, the use of the aluminium alloy article for printing plate, and a process of producing an aluminium alloy sheet/strip/foil for printing plate using the aluminium alloy.

1 . An aluminium alloy, comprising Al, Si, Fe, Mg, Cu, Ti and optionally other impurities, characterized in that the components are comprised in amounts by weight of: Si: 0.04-0.1%, Fe: 0.25-0.4%, Mg: 0.055-0.12%, Cu: 0.004-0.01%, Ti: 0.003-0.02%; any one of the other impurities is in an amount by weight of no more than 0.03%; and the balance is Al. 
     
     
         2 . The aluminium alloy according to  claim 1 , characterized in that Mg/Fe>=0.125. 
     
     
         3 . The aluminium alloy according to  claim 1 , characterized in that Mg is comprised in an amount of not less than 0.06%, preferably not less than 0.07%; and/or Mg is comprised in an amount of not more than 0.11%, preferably not more than 0.10%. 
     
     
         4 . The aluminium alloy according to  claim 1 , characterized in that Cu is comprised in an amount of not less than 0.0045%, preferably not less than 0.005%; and/or Cu is comprised in an amount of not more than 0.009%, preferably not more than 0.008%. 
     
     
         5 . The aluminium alloy according to  claim 1 , characterized in that Ti is comprised in an amount of not less than 0.004%, preferably not less than 0.005%; and/or Ti is comprised in an amount of not more than 0.019%, preferably not more than 0.017%. 
     
     
         6 . The aluminium alloy according to  claim 1 , characterized in that the impurities comprise Li, Na, Pb, Be, Zn and/or V. 
     
     
         7 . The aluminium alloy according to  claim 1 , characterized in that the total amount of the impurities is at most 0.1 wt %. 
     
     
         8 . The aluminium alloy according to  claim 1 , characterized in that Al is comprised in an amount of not less than 99.30%. 
     
     
         9 . An article comprising the aluminium alloy according to  claim 1 . 
     
     
         10 . The article according to  claim 9 , characterized in being in the form of strip, foil or sheet. 
     
     
         11 . The article according to  claim 10 , characterized in that the aluminium sheet/strip/foil has a thickness of about 0.14 mm to about 0.5 mm, preferably about 0.18 mm to about 0.38 mm. 
     
     
         12 . The article according to  claim 9 , characterized in having a tensile strength of about 175 to about 210 MPa, a yield strength of about 170 to about 200 MPa, and/or an elongation of about 2% to about 6%, at room temperature; and
 in that through a simulated baking condition treatment at a temperature of 240 degrees centigrade for 10 minutes, the aluminium alloy article, after cooling, has a tensile strength of about 145 to about 170 MPa, a yield strength of about 135 to about 155 MPa, and/or an elongation of about 3% to about 8%.   
     
     
         13 . Use of the article according to  claim 9  for computer-to-plate. 
     
     
         14 . A process of producing an aluminium alloy sheet/strip/foil for printing plate using the alloy according to  claim 1 , characterized in comprising the steps of:
 1) adding the alloy components as defined in  claim 1  into a remelting furnace, melting, refining, inclusion removing, degassing and filtering, followed by casting into a sheet ingot with a thickness of about 500 to about 650 mm;   2) sawing the head and butt of the sheet ingot, scalping, and then heating to a temperature of about 500 to about 600 degrees centigrade for about 2 to about 12 hours; and hot rolling the sheet ingot into a strip with a thickness of about 2.0 to about 5.0 mm at a temperature of about 250 to about 320 degrees centigrade;   3) cold rolling the strip to a thickness of about 1 to about 3 mm, wherein the roll has a roughness, Ra, of about 0.30 to about 0.80 μm;   4) annealing the cold rolled strip from step 3) in an annealing furnace at a temperature of about 350 to about 450 degrees centigrade, and holding the temperature for about 2 to about 4 hours;   5) continuing rolling the strip from step 4) on a cold roller to a thickness of about 0.14 to about 0.4 mm, with a Ra of about 0.15 to about 0.30 μm; and   6) cleaning the strip from step 5), edge trimming, and tension leveling, to obtain the aluminium alloy sheet, strip or foil.