China Foundry
Title: Effects of Ag, Co, and Ge additions on microstructure and mechanical properties of Be-Al alloy fabricated by investment casting
Author: Yao Xie1, 2, Ya-jun Yin1, Dong-xin Wang2, *Jian-xin Zhou1, Jun-yi Li2, Xiao-yuan Ji1, Zhao-gang Liu2, Xu Shen1, and Wei Fu3
Address: 1. State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science & Technology, Wuhan 430074, China; 2. State Key Laboratory of Special Rare Metal Materials, Northwest Rare Metal Materials Research Institute Ningxia Co., Ltd., Shi Zuishan753000, Ningxia, China; 3. State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China
Key words: Be-Al alloys; solution strengthening; investment casting; mechanical properties
CLC Nmuber: TG146.24
Document Code: A
Article ID: 1672-6421(2022)05-435-08
Abstract:
The effects of Ag, Co, and Ge additions on microstructure and mechanical properties of Be-35Al (wt.%) alloys fabricated by investment casting were studied. The results reveal that the trace metals 1.5wt.% Ag, 0.7wt.% Co, and 0.8wt.% Ge additions do not change the nucleation temperature of Be phase. However, the nucleation temperature of the Al phase decreases from 642 °C to 630 °C by DSC due to the Ge addition. The strength of the alloys sharply increases due to the dissolution of the Ag and Ge solutes into the Al phase and the Co into the Be phase characterized by SEM and EDS. Obviously, the strength of Be-Al-Ag-Co-Ge alloy is improved by the solution strengthening. Furthermore, a few Ag3Al particles contribute to the strength of the Al phase. Be-Fe-Al ternary intermetallic compounds which can effectively reduce the negative effect of an impurity element Fe on the mechanical properties of Be-Al alloys are also found by XRD and EDS.