Alloy for magnesium and magnesium alloy grain refinement and preparation method thereof

Abstract

The present invention provides an alloy for magnesium and magnesium alloy grain refinement, and a preparation method thereof, the alloy as a grain refiner being an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 5-20% of Zr, 0.5-4% of B, and the balance being Al. The invention can achieve the following technical effect: an intermediate alloy with strong nucleation capability and excellent capability of magnesium and magnesium alloy grain refinement is invented and its preparation method is provided. This kind of grain refiner can be applied to casting deformation plastic processing of magnesium and magnesium alloy profiles, with high degree of refinement, to promote the extensive industrial applications of magnesium.

1 . An alloy for magnesium and magnesium alloy grain refinement, wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 5-20% of Zr, 0.5-4% of B, and the balance being Al. 
     
     
         2 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 5.0±0.5% of Zr, 0.5±0.25% of B and the balance being Al. 
     
     
         3 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 5.0±0.5% of Zr, 1.0±0.25% of B and the balance being Al. 
     
     
         4 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 10.0±1.0% of Zr, 2.0±0.3% of B and the balance being Al. 
     
     
         5 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 15.0±2.0% of Zr, 3.0±0.5% of B and the balance being Al. 
     
     
         6 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the grain refiner is an aluminum-zirconium-boron intermediate alloy comprising the following chemical compositions by weight percent: 20.0±3.0% of Zr, 4.0±0.7% of B and the balance being Al. 
     
     
         7 . The alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , wherein the impurities of said aluminum-zirconium-boron intermediate alloy comprise the following chemical compositions by weight percent: Fe≦0.5%, Si≦0.3%, Cu≦0.2%, Cr≦0.2% and other single impurity element≦0.2%. 
     
     
         8 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 1 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         9 . The preparation method according to  claim 8 , wherein the mole fraction f fluorozirconate to fluoroborate is 1:2 to 1:1. 
     
     
         10 . The preparation method according to  claim 8 , wherein the fluorozirconate is potassium fluorozirconate or sodium fluorozirconate, and the fluoroborate is potassium fluoroborate or sodium fluoroborate. 
     
     
         11 . The preparation method according to  claim 9 , wherein the fluorozirconate is potassium fluorozirconate or sodium fluorozirconate, and the fluoroborate is potassium fluoroborate or sodium fluoroborate. 
     
     
         12 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 2 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         13 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 3 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         14 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 4 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         15 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 5 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         16 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 6 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.   
     
     
         17 . A preparation method of alloy for magnesium and magnesium alloy grain refinement according to  claim 7 , comprising the following steps:
 Step A: Add aluminum in a reactor, heat it to 700-850° C., and add the mixture of fluorozirconate and fluoroborate to the reactor;   Step B: After stirring 4-6 hours, extract the upper layer of molten liquid, to remain the lower layer of aluminum-zirconium-boron alloy;   Step C: After deslagging and heat preservation, the resulting aluminum-zirconium-boron alloy can be directly cast, particularly prepared into wire rod with diameter of 9.5 mm in a way of continuous casting and rolling or continuous casting and extrusion;   wherein the aluminum is added excessively.