Effect of Sc, Zr Grain Refiner on the Microstructure and Mechanical Properties of Pure Aluminum

• Published in: Applied Mechanics and Materials Vol. 508; no. Research on Energy Material, Chemical Engineering and Mining Engineering II; pp. 16 - 21
• Main Authors: Yang, Cheng Gang, Wang, Shang Lin, Zheng, Qiang, Yu, Ai Wu, Liu, Fen Cheng
• Format: Journal Article
• Language: English
• Published: Zurich Trans Tech Publications Ltd 2014
• Subjects: Alloys; Aluminum; Aluminum base alloys; Grain refinement; Hardness; Intermetallic compounds; Mechanical properties; Microstructure; Strengthening; Zirconium; Solid Solution Strengthening; Fine-Grain Strengthening; Microstructure; Mechanical Property; Nucleation Sites; Composite Particles
• DOI: 10.4028/www.scientific.net/AMM.508.16
• ISBN: 3038350168; 9783038350163
• ISSN: 1660-9336; 1662-7482

The influence of grain refiner on the microstructure and mechanical properties of pure aluminum was investigated by separate and combined addition trace ScZr elements. The results show that the grain refinement effect of 0.2%Zr added alone is better than that of 0.2%Sc, each of them separate addition can make the strength and hardness of alloys increased obviously, and the decrease of the ductility is not remarkable, but the hardness increase of the alloy with 0.2%Sc is more significant than 0.2%Zr because of the strongly solid solution strengthening of Sc. While, the combined addition of 0.2%Sc and 0.2%Zr possesses the most excellent grain refining effect and change the growth morphology from columnar grains to equiaxed ones, the average grain size of the alloy is dropped to only about 100μm, and the strength, plastic and hardness of the alloy meet the reasonable matching, which is largely attributed to the effectively reduce of the Al-Sc eutectic point and the formation of Al3(Sc, Zr) composite particles, These Al3(Sc, Zr) particles can not only keep all the beneficial effect of A13Sc but can act as extremely effective nucleation sites of α (Al) and cause strongly fine-grain strengthening effect.