Effect of lanthanum addition on microstructure and hardness of brass alloys produced by rheological squeeze casting

作     者：Wenjing Gao Shuming Xing Ying Wang Wenjing Gao;Shuming Xing;Ying Wang

作者机构：School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing 100044China School of Mechatronics and Vehicle EngineeringZhengzhou University of TechnologyZhengzhou 450044China 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2022年第40卷第12期

页      面：1953-1962,I0006页

核心收录：

学科分类：08[工学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 

基　　金：Project supported by the financial support of the Fundamental Research Funds for the Central Universities(2020YJS146) 

主　　题：Rheological squeeze casting La Brass alloy Grain refinement Rare earths 

摘      要：The effect of La addition(0-0.30 wt%)on the microstructure and hardness of rheological squeeze casting brass alloys was experimentally *** rheological squeeze casting process is improved by controlling the wall surface crystals and melt flow rate to realise the preparation of semi-solid melt with flow,and a brass alloy workpiece with La is *** microstructure and properties of the brass alloy samples were investigated using metallography,scanning electron microscopy,energy-dispersive X-ray spectroscopy,X-ray diffraction and hardness *** results indicate that the hardness of the rheological squeeze casting brass alloy is increased by 20.4%from 108 to 130 HBW with an increase in the La content from 0 to 0.30 wt%.The micro structural analysis results show that La significantly refines the primary a-phase grains,and the main mechanism is the constitutional undercooling and heterogeneous nucleation caused by the La enrichment in the front of the solid-liquid *** squeeze pressure promotes undercooling,which improves the nucleation rate and affects the solute diffusion and nucleus *** dual effects of these two aspects aggravate the grain refinement process,consequently increasing the number of grain boundaries and improving the hardness of the brass alloy.