Aluminium alloy refiner and preparation method and application thereof

Abstract

The present invention provides an aluminium alloy refiner. The aluminium alloy refiner is characterized by comprising 7 to 10 parts of Ti, 2 to 3 parts of B and the balance of Al by weight, for example, 8 parts of Ti, 3 parts of B and 89 parts of Al by weight. The aluminium alloy refiner is prepared by rapid solidification. After the refiner is added to A356.2 aluminium alloy, the grain size of the alloy is significantly reduced than that of the aluminium alloy treated by a conventional refiner. Moreover, the solubility of metals in liquid may be increased due to rapid solidification, such that the refiner is more easily absorbed by the aluminium alloy melt after being added to the aluminium alloy.

1 . An aluminium alloy refiner, characterized in that the aluminium alloy refiner comprises 7 to 10 parts of Ti, 2 to 3 parts of B and 87 to 91 parts of Al by weight;
 preferably, the aluminium alloy refiner comprises 7.5 to 9 parts of Ti, 2.5 to 3 parts of B and 88 to 90 parts of Al by weight;   further preferably, the aluminium alloy refiner comprises 8 to 8.5 parts of Ti, 2.5 to 3 parts of B and 89 to 90 parts of Al by weight;   for example,   (1) the aluminium alloy refiner comprises 8 parts of Ti, 3 parts of B and 89 parts of Al by weight;   (2) the aluminium alloy refiner comprises 7 parts of Ti, 2 parts of B and 91 parts of Al by weight;   (3) the aluminium alloy refiner comprises 7.5 parts of Ti, 2.5 parts of B and 90 parts of Al by weight;   (4) the aluminium alloy refiner comprises 8.5 parts of Ti, 2.5 parts of B and 89 parts of Al by weight;   (5) the aluminium alloy refiner comprises 9 parts of Ti, 3 parts of B and 88 parts of Al by weight; and   (6) the aluminium alloy refiner comprises 10 parts of Ti, 3 parts of B and 87 parts of Al by weight.   
     
     
         2 . The aluminium alloy refiner according to  claim 1 , characterized in that the aluminium alloy refiner is composed of alpha-Al phases, granulous TiAl 3  phases and TiB 2  particle phases. 
     
     
         3 . The aluminium alloy refiner according to  claim 1 , characterized in that the size of the granulous TiAl 3  phases of the aluminium alloy refiner is less than 1.0 micrometer, and preferably is 0.6 to 1.0 micrometer. 
     
     
         4 . The aluminium alloy refiner according to  claim 1 , characterized in that the size of the TiB 2  particle phases of the aluminium alloy refiner is less than 60 nm, and preferably is 30 to 60 nm. 
     
     
         5 . The aluminium alloy refiner according to  claim 1 , characterized in that the aluminium alloy refiner is prepared by rapid solidification. 
     
     
         6 . The method of preparing the aluminium alloy refiner according to  claim 1 , characterized in that the method comprises the following steps:
 (1) mixing raw materials in proportion, and placing them into a quartz tube with an opening at the lower end, and heating the quartz tube until test blocks in the quartz tube are completely melted, preferably, the diameter of a small space of the opening at the lower end of the quartz tube being 0.3 to 0.6 mm, and most preferably is 0.4 mm;   (2) injecting melt in the quartz tube onto a rotating copper roller, preferably the copper roller rotating at a rotation speed of 50 to 65 revolutions per second, and most preferably at a rotation speed of 60 revolutions per second.   
     
     
         7 . The method according to  claim 6 , characterized in that the raw materials are industrial Al—Ti—B intermediate alloy, elemental Ti particles and elemental B particles. 
     
     
         8 . The method of refining the aluminium alloy by using the aluminium alloy refiner of  claim 1 , characterized by comprising the following steps:
 (1) heating and melting aluminium alloy ingot castings, then stirring at a low speed, keeping still and skimming surface dross;   (2) adding the aluminium alloy refiner of any one of  claims 1  to  5  or the aluminium alloy refiner prepared according to the method of any one of  claims 6  to  7  to aluminium alloy melt, wherein the addition quantity of the aluminium alloy refiner accounts for 0.15% to 0.30% of the mass fraction of the aluminium alloy melt, and skimming the surface dross after the refiner is completely melted and heat preservation is carried out on the melt for 10 minutes; slowly introducing high-purity argon into the melt for refining, wherein the refining temperature is 720 degrees Celsius, stirring slowly during introduction of the gas, and removing the surface dross again after ending refining;   (3) keeping the melt with the temperature of 720 degrees Celsius still, and then slowly pouring the melt into a preheated cast iron mould;   preferably, the aluminium alloy is A356.2 aluminium alloy;   preferably, the addition quantity accounts for 0.20% of the mass fraction of the aluminium alloy melt.   
     
     
         9 . The aluminium alloy refined according to the method of  claim 8 . 
     
     
         10 . The application of the aluminium alloy obtained by treatment according to the method of  claim 8  in aluminium wheel casting.