纤维增强Cu-15Cr-0.24Zr合金组织演变及抗拉强度

Microstructure evolution and tensile strength of fiber reinforcement Cu-Cr-Zr alloy

采用真空中频感应熔炼技术制备组织均匀的Cu-15Cr-0.24Zr合金铸锭,采用冷拔与冷轧相结合的变形工艺获得超高强度的薄板材料。利用扫描电镜、能谱仪、透射电镜和万能试验机研究合金枝晶Cr到纤维Cr的演变过程、铸态组织组成相的成分、冷轧变形量为95%时的Cu/Cr界面关系和合金不同变形阶段的抗拉强度。结果表明：随着变形量的增大,Cr枝晶演变为分布均匀、平行排列的Cr纤维,且Cr纤维的横截面经历了＂V＂形向＂一＂形的转变;Cu/Cr界面呈半共格关系排列,错配度为0.041,表明Cu/Cr界面结合良好;增大冷拔变形量,可以显著提高冷拔结合冷轧变形工艺制备的薄板材料的抗拉强度,当冷拔变形量从2.41增大到3.79时,冷轧变形量为95%时,薄板材料的抗拉强度从749 MPa升高到1011 MPa。

The homogeneous Cu-15 Cr-0. 24 Zr alloy ingot was prepared by vacuum medium-frequency induction smelting technology. Ultra high strength sheet material was obtained by the deformation process combined with cold drawing and cold rolling. The evolution process of dendritic Cr to fiber Cr,composition of the as-cast microstructure,relationship between Cu/Cr interface of the tested alloy with the cold rolling deformation of 95% and the tensile strength of the tested alloy at different deformation stages were studied by means of scanning electron microscopy, energy dispersive spectrometer analysis, transmission electronic microscopy and universal testing machine,respectively. The results show that with the increasing of the deformation,the Cr dendrites evolve into Cr fibers with uniform distribution and parallel arrangement,and the cross section of Cr fibers undergoes a transformation from ＂V＂to ＂一＂. The Cu/Cr interface is arranged in a semi-lattice relationship,and the mismatch degree is 0. 041,indicating that the Cu/Cr interface is well bonded. The increase of cold drawing deformation can significantly improve the tensile strength of the thin sheet materials prepared by cold drawing combined with cold rolling deformation process. When the cold drawing deformation increases from 2. 41 to 3. 79 and the cold rolling deformation is 95%,the tensile strength of the final sheet material increases from 749 MPa to 1011 MPa.