Cu-Cr-Zr系合金中Zr含量对初生相的影响

Effect of Zr content on primary phase in Cu-Cr-Zr alloy

采用大气熔铸的方法制备了不同Zr元素含量的Cu-Cr-Zr系合金。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、能谱分析（EDS）等检测手段,分析了不同Zr元素含量对Cu-Cr-Zr系合金初生相形貌、分布、成分和尺寸等方面的影响,同时还观察了时效析出相。结果表明：Cu-Cr-Zr系合金中初生相主要沿晶界分布,初生富Cr相有多边形、椭圆形和短棒状3种形貌,其成分为Cr3Si,是面心立方结构。初生含Zr相主要为细长的针状,为Cu5Zr相。时效时间对初生相形貌和尺寸的影响不大,但会影响初生富Cr相的数量,Zr元素含量提高会阻碍初生富Cr相的长大,促进初生相的球化过程,这与界面能σ和弹性应变能ΔΕ的相对大小有关;时效析出相有豆瓣衬度和椭圆形两种形貌,且与基体完全共格。

The Cu-Cr-Zr alloys with different Zr contents were prepared by atmospheric casting.The effects of Zr contents on the morphology,distribution,composition and size of the primary phase in the Cu-Cr-Zr alloy were analyzed by using scanning electron microscopy（SEM）,transmission electron microscopy（TEM）,energy spectrum analysis（EDS）and other detection means.At the same time,the ageing precipitation phases were also observed.The results show that in the Cu-Cr-Zr alloy,the primary phase is mainly distributed along the grain boundary and its morphology is of polygonal,elliptical and short rod shapes,and its composition is Cr3Si with the FCC structure,while the primary Zr-bearing phase is Cu5Zr phase mainly with elongated needle shape.The aging time has little effect on the morphology and size of the primary Cr-rich phase,but it will affect the amount of the primary Cr-rich phases.The increase of Zr content hinders the growth of the primary Cr-rich phase,but promotes its spheroidization process,which related to the value of the interface energyσand the elastic strain energyΔΕ.The ageing precipitation phases have coffee beans contrast and ellipse shape,and coherent with the matrix.