Alnbbre refiner with low cooling rate sensitivity and high nucleation ability for cast aluminum alloy and preparation method thereof

Abstract

The invention discloses a low-cooling-rate-sensitivity high-nucleation-capability AlNbBRE grain refiner for cast aluminum alloy and a method for preparing the refiner by adopting induction smelting; the ingredients of the refiner are Al-xNb-yB-zRE, wherein x is larger than 0.01wt% and smaller than or equal to 6wt%, y is larger than 0.01wt% and smaller than or equal to 3wt%, z is larger than 0.01wt% and smaller than or equal to 1wt%, and the balance is Al; RE is one of or a mixture of two of La, Ce, Nd, Er, Gd, Y, Yb and Sc. The method is simple in preparation process and capable of accurately controlling the ingredients of the refiner. The refiner is excellent in refining effect when being used for performing grain refinement on cast aluminum-silicon alloy and is relatively low in cooling rate sensitivity on the refining effect of the positions, complicated in shape and different in thickness, of a cast piece, namely of the positions different in cooling rate; the mechanical properties of the refined alloy are remarkably improved; the performance differences of the positions which are different in cooling rate are remarkably reduced.

Description

technical field

[0001] The invention relates to a refiner for casting aluminum alloys, more particularly to an Al-Nb-B-RE grain refiner for casting aluminum alloys with low cooling rate sensitivity and high nucleation ability. Background technique

[0002] Aluminum-silicon alloys are widely used in industry due to their good mechanical properties and excellent casting properties. Refining the grains of the alloy can obtain a dense alloy structure, and at the same time reduce the tendency of hot cracking and segregation of the casting, and reduce the porosity, thereby improving the overall performance of the alloy. The most common and effective refinement method is to add grain refiners to the alloy. At present, people generally use Al-Ti, Al-Ti-C or Al-Ti-B master alloy as the grain refiner of aluminum alloy, among which Al-Ti-B refiner has been widely used. Recently, due to Rare earth elements (RE) have excellent physical and chemical properties, and people have also begu...

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