Affiliation:
1. School of Resources, Environment and Materials Guangxi University Nanning Guangxi 530004 China
2. State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures Guangxi University Nanning Guangxi 530003 China
3. Guangxi Key Laboratory of Petrochemical Resource Processing and Process Intensification Technology Guangxi University Nanning 530004 China
4. Key Laboratory of High-Performance Structural Materials and Thermo-Surface Processing Education Department of Guangxi Zhuang Autonomous Region Guangxi University Nanning 530004 China
Abstract
The microstructure and mechanical properties of cast Al‐Cu‐Mn alloy influenced by various Sc additions (viz. 0.1, 0.2, 0.3, 0.4, and 0.5 wt%) are investigated. It is found that the grain size of α‐Al and the area proportion of the second phase are decreased with the addition of Sc. In addition, the morphology of the precipitated phase in Al‐Cu‐Mn alloy also evolves at different stages, and the solidification temperature range and initial enthalpy change of the alloy are changed, resulting in the formation of a variety of second‐phase containing Sc. Owing to the grain refinement and precipitation strengthening effects, the hardness of as‐cast alloys is better than T6 alloys. Moreover, it is observed that when the Sc content is 0.3%, the mechanical properties of the as‐cast Al‐Cu‐Mn alloy are the minimum, and the Al‐Cu‐Mn alloys after T6 heat treatment are the maximum. These results confirm that the mechanical properties improvement effect of the as‐cast Al‐Cu‐Mn alloy is greater than that of the T6 heat treatment Al‐Cu‐Mn alloy with the addition of Sc. Meanwhile, the Orowan strengthening mechanism is found to have lost its dominant position.
Subject
Materials Chemistry,Electrical and Electronic Engineering,Surfaces, Coatings and Films,Surfaces and Interfaces,Condensed Matter Physics,Electronic, Optical and Magnetic Materials