论文部分内容阅读
研究Ni的添加及时效处理对Cu-3Ti合金组织与性能的影响。采用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)及高分辨透射电子显微镜(HRTEM)对Cu-3Ti-1Ni合金的组织和析出相进行表征,并对其硬度和导电率进行测试。结果表明:Ni的添加导致铸态Cu-3Ti合金在凝固过程中形成Ni Ti相,组织由树枝晶转变为等轴晶。时效处理后析出共格的亚稳定β’-Cu4Ti相,过时效导致β’-Cu4Ti相转变为非共格的层片稳定相Cu3Ti。同时,时效处理导致出现了退火孪晶,且在合金基体中发现位错线的聚集。Ni的添加提高了Cu-3Ti合金的导电率,降低了其硬度。在实验范围内,Cu-3Ti-1Ni合金的最佳时效处理工艺是300°C时效2 h后炉冷,随后450°C时效7 h炉冷,其硬度及导电率分别是HV 205及18.2%IACS(国际退火铜标准)。
The effect of Ni addition and aging treatment on the microstructure and properties of Cu-3Ti alloy was studied. The microstructure and precipitated phase of Cu-3Ti-1Ni alloy were characterized by optical microscope (OM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) Conductance were tested. The results show that the addition of Ni results in the formation of Ni-Ti phase in the as-cast Cu-3Ti alloy during solidification and the transformation of dendrite into equiaxed grains. After the aging treatment, a metastable β’-Cu4Ti phase precipitates out of phase and the over-aging results in the transformation of the β’-Cu4Ti phase to a non-coherent layer stable phase Cu3Ti. At the same time, aging treatment led to the occurrence of annealing twins, and dislocation line aggregation was found in the alloy matrix. The addition of Ni improves the conductivity of the Cu-3Ti alloy and reduces its hardness. In the experimental range, the best aging treatment process of Cu-3Ti-1Ni alloy is furnace cooling at 300 ° C for 2 h, followed by furnace cooling at 450 ° C for 7 h with hardness and conductivity of HV 205 and 18.2% IACS (International Annealed Copper Standard).