Mo含量对含β相TiAl合金组织和力学性能的影响.pdfVIP

Trans. Nonferrous Met. Soc. China 27(2017) 820−828 Influence of Mo content on microstructure and mechanical properties of β -containing TiAl alloy 1,2 1 1 1 1,2 Wen-chen XU , Kai HUANG , Shi-feng WU , Ying-ying ZONG , De-bin SHAN 1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; 2. National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China Received 8 January 2016; accepted 27 August 2016 Abstract: The influence of Mo content on the microstructure and mechanical properties of the Ti−45Al−5Nb−xMo−0.3Y (x=0.6, 0.8, 1.0, 1.2) alloys was studied using small ingots produced by non-consumable electrode argon arc melting. The results show that small quantities of β phase are distributed along γ/α lamellar colony boundaries as discontinuous network in the TiAl alloys owing to the 2 segregation of Mo element. The γ phase forms in the interdentritic microsegregation area when the Mo addition exceeds 0.8%. The β and γ phases can be eliminated effectively by subsequent homogenization heat treatment at the temperature above T . The evolution α of the strength, microhardness and ductility at different Mo contents under as-cast and as-homogenization treated conditions was analyzed, indicating that excessive Mo addition is prone to cause