Mg-al magnesium alloy, preparation method for tube made of mg-al magnesium alloy, application of mg-al magnesium alloy

Abstract

The present disclosure discloses a Mg—Al based magnesium alloy, and a preparation method of a tube and an application of the same, and belongs to the technical field of alloy materials. The magnesium alloy includes, by weight percentage, 7.0-8.6% Al, 0.8-2.0% RE, 0.2-0.8% Mn, and a balance of Mg, and the magnesium alloy has an elongation of 15-22%. The preparation method of a tube of the Mg—Al based magnesium alloy includes: mixing and smelting an Al source, a RE source, a Mn source, and a Mg source to give a liquid mixed metal; casting the liquid mixed metal into a bar through semi-continuous casting; performing homogenization heat treatment on the bar at 360-400° C. for 6-10 h; and performing extrusion-forming on the heat-treated bar to obtain a magnesium alloy tube. The Mg—Al based magnesium alloy of the present disclosure has high elongation, and the elongation of the tube formed using the same can reach 15-22%, so that it can withstand large plastic deformation. Meanwhile, the Mg—Al based magnesium alloy has excellent welding performance and a welding loss rate of less than 6%, which greatly reduces the strength loss of magnesium alloy profiles after welding, and ensures the strength of magnesium alloy profiles after welding. The Mg—Al based magnesium alloy can be used in the fields of vehicle equipment and medical equipment.

1 . A Mg—Al based magnesium alloy comprising, by weight percentage, 7.0-8.6% Al, 0.8-2.0% RE, 0.2-0.8% Mn, and a balance of Mg, the magnesium alloy having an elongation of 15-22%. 
     
     
         2 . The Mg—Al based magnesium alloy according to  claim 1 , wherein in the magnesium alloy, the weight percentage of Al is 7.0-8.2%, the weight percentage of RE is 1.1-2.0%, and the weight percentage of Mn is 0.4-0.8%. 
     
     
         3 . The Mg—Al based magnesium alloy according to  claim 2 , wherein in the magnesium alloy, the weight percentage of Al is 7.8-8.2%, the weight percentage of RE is 1.3-1.9%, and the weight percentage of Mn is 0.5-0.8%; and in the RE, the weight percentage of Y is 0.8-1.6%, and the mass percentage of Ce is 0-0.8%. 
     
     
         4 . The Mg—Al based magnesium alloy according to  claim 1 , wherein the magnesium alloy has an elongation of 17-21.6%. 
     
     
         5 . The Mg—Al based magnesium alloy according to  claim 1 , wherein the magnesium alloy has a welding loss rate of less than 6%. 
     
     
         6 . The Mg—Al based magnesium alloy according to  claim 1 , wherein the magnesium alloy has a yield strength of 182-235 MPa and a tensile strength of 306-342 MPa. 
     
     
         7 . The Mg—Al based magnesium alloy according to  claim 1 , wherein the RE comprises at least one of La, Ce, Nd, Y, Gd, Ho, Dy, and Er. 
     
     
         8 . A preparation method of a tube of a Mg—Al based magnesium alloy, comprising steps of:
 mixing an Al source, a RE source, a Mn source, and a Mg source in element weight percentage contents of 7.0-8.6% Al, 0.8-2.0% RE, 0.2-0.8% Mn, and a balance of Mg to obtain a mixture, and smelting the mixture to give a liquid mixed metal; 
 casting the liquid mixed metal into a bar through semi-continuous casting; 
 performing homogenization heat treatment on the bar at 360-400° C. for 6-10 h; and 
 performing back extrusion forming on the heat-treated bar to obtain the magnesium alloy tube. 
 
     
     
         9 . An application of the Mg—Al based magnesium alloy according to any one of  claim 1  in fields of vehicle equipment and medical equipment.