Aluminium-titanium-niobium-boron intermediate alloy and preparation method and application thereof

A preparation method of an aluminium (Al)-titanium (Ti)-niobium (Nb)-boron (B) intermediate alloy, comprising:

• ball milling potassium tetrafluoroborate (KBF4) powder, Nb powder, and Ti powder to obtain mixed powder;
• pressing the mixed powder to obtain a ball-milled block;
• melting an Al block at 750-800 degree Celsius (° C.) to obtain an Al melt;
• adding the ball-milled block to the Al melt followed by smelting to obtain alloy liquid;
• and casting the alloy liquid to obtain the Al—Ti—Nb—B intermediate alloy;
• wherein a particle size of the Nb powder is in a range of 30 micrometers (m) to 50 μm, and a particle size of the Ti powder is in a range of 1 μm to 50 μm;
• wherein a rotation speed in the ball milling is in a range of 200 revolutions per minute (r/min) to 300 r/min, and time of the ball milling is in a range of 4 hours (h) to 6 h;
• wherein a temperature of the smelting is in a range of 750° C. to 800° C., and time of the smelting is in a range of 20 minutes (min) to 60 min;
• wherein the Al—Ti—Nb—B intermediate alloy comprises the following compositions in percentage by weight:
• Al:
• 94.9%-96.7%, Ti:
• 0.5%-1.5%, Nb:
• 2.5%-4%, B:
• 0.3%-0.8%;
• and
• wherein the Al—Ti—Nb—B intermediate alloy comprises refined nucleating phases, the refined nucleating phases are (Nb/Ti)Al3 and (Nb/Ti)B2, a weight percentage of the refined nucleating phases in the Al—Ti—Nb—B intermediate alloy is in a range of 1% to 6%, a particle size of the refined nucleating phases is in a range from 1 m to 80 μm, and a particle size of the (Nb/Ti)B2 is not greater than 5 μm.