Ag-Cu-Co体系的相图热力学研究  

Thermodynamic investigation of the Ag-Cu-Co system

作　　者：毛学良 李晓静 刘树红[1] 杜勇[1] MAO Xueliang;LI Xiaojing;LIU Shuhong;DU Yong(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China)

机构地区：[1]中南大学粉末冶金国家重点实验室,长沙410083

出　　处：《粉末冶金材料科学与工程》2022年第5期460-470,共11页Materials Science and Engineering of Powder Metallurgy

基　　金：云南省贵金属基因工程重大科技项目(202002AB080001-1)。

摘　　要：通过电感耦合等离子体发射光谱仪、电子探针显微分析仪和X射线衍射仪研究铸态及400℃、650℃退火态Ag-Cu-Co合金的相组成。结果表明,铸态和退火态Ag-Cu-Co合金中均未观测到Ag-Cu-Co三元化合物。400℃退火态合金中,Cu和Co在FCC(Ag)中的最大溶解度分别为9.78%和0.88%(摩尔分数,%,下同),Ag和Co在FCC(Cu)中以及Ag和Cu在HCP(Co)中的最大溶解度则分别为2.37%和0.98%,以及0.22%和4.15%。而650℃退火态合金中,Cu和Co在FCC(Ag)中,Ag和Co在FCC(Cu)中以及Ag和Cu在FCC(Co)中的最大溶解度分别为15.74%和0.97%,3.69%和4.47%,以及0.15%和7.48%。采用CALPHAD(calculationofphasediagram)方法,基于文献报道的Ag-Cu、Ag-Co和Cu-Co二元系的热力学参数外推,获得了Ag-Cu-Co三元体系的热力学数据库。使用该数据库计算Ag-Cu-Co体系400℃和650℃等温截面、液相面投影图及三元合金的凝固路径,计算结果与实验数据一致,说明CALPHAD外推获得的三元体系热力学描述的准确性。Phase constituents of the Ag-Cu-Co alloys in as-cast and annealed at 400 ℃ and 650 ℃ were studied by inductively coupled plasma optical emission spectrometer(ICP-OES), electron probe microanalysis(EPMA) and X-ray diffraction(XRD). The results show that no ternary compound is observed in this work. At 400 ℃, the maximum solubility of Cu and Co in FCC(Ag), Ag and Co in FCC(Cu) and Ag and Cu in HCP(Co) are determined to be 10.08%and 1.43%, 2.37% and 0.98%, as well as 0.22% and 4.15%(mole fraction, %, the same below), respectively. While at 650 ℃, the maximum solubility of Cu and Co in FCC(Ag), Ag and Co in FCC(Cu) and Ag and Cu in FCC(Co) are determined to be 15.74% and 0.97%, 3.69% and 4.47% as well as 0.15% and 7.48%, respectively. Thermodynamic database of the Ag-Cu-Co system is extrapolated from the reported thermodynamic description of the three sub-binary systems of Ag-Cu, Ag-Co and Cu-Co in literature, based on the CALPHAD(calculation of phase diagram) approach.Using the presently obtained database, the isothermal sections at 400 ℃ and 650 ℃, the liquidus projection as well as the solidification path of the Ag-Cu-Co system are calculated. The reasonable agreement between the calculations and measurement indicates the accuracy of the thermodynamic description of the Ag-Cu-Co system obtained by extrapolation using the CALPHAD approach.

关 键 词：Ag-Cu-Co 等温截面 液相面投影图 CALPHAD 凝固路径 

分 类 号：TG113.14[金属学及工艺—物理冶金]