Precipitation process and its effects on properties of aging Cu-Ni-Be alloy

• Published in: Rare metals 2013-08, Vol.32 (4), p.332-337
• Main Authors: Peng, Li-Jun, Xiong, Bai-Qing, Xie, Guo-Liang, Wang, Qiang-Song, Hong, Song-Bai
• Format: Article
• Language: English
• Subjects: AGING MECHANISMS; Biomaterials; Chemistry and Materials Science; COPPER ALLOYS (40 TO 99.3 CU); Copper base alloys; ELECTRICAL CONDUCTIVITY; Electron microscopy; Energy; HRTEM; Materials Engineering; Materials Science; Metallic Materials; Nanoscale Science and Technology; PHASE TRANSFORMATIONS; Physical Chemistry; PRECIPITATES; Precipitation; Strengthening; Tensile strength; Transformations; X-射线衍射; YIELD STRENGTH; 合金; 方向关系矩阵; 沉淀过程; 老化性能; 降水过程; 高分辨透射电子显微镜
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-013-0074-5

The precipitation process of aged Cu-Ni-Be alloy was investigated by X-ray diffraction （XRD）, trans- mission electron microscopy （TEM）, and high-resolution transmission electron microscopy （HRTEM）. The tensile strength, yield strength, and electronic conductivity of this alloy after aging were also studied. The precipitation sequence of the C17510 alloy aged at 525 ℃ is supersat-urated solid solution→G.P zones→ γ″-γ′→ γ. This transformation can be achieved by the accumulation of Be-atom layers. The G.P zones are composed of disk-shaped monolayers of Be atoms, which are formed on （001） matrix planes. The intermediate γ″ precipitate is nucleated in the G.P zones. The γ″ and γ′ precipitates have the same orientation relationship with matrix, e.g., （110）p｜｜（100）M,[001]p｜｜[001]M. The tensile strength of specimen shows a maximum during the aging process and then continuously decreases if the specimen is over aged. The strengthening effect of γ′ phase precipitated in aging at 525 ℃ for 4 h is calculated to be 436 MPa according to the Orowan strengthening, which is quite consistent with the experimental data.