论文部分内容阅读
利用XRD和热场发射(FESEM)等分析了不同含铜量Al-Si-Cu-Ni-Mg活塞合金富镍相的演变。研究结果表明:随着Cu含量的增加,镍相由Al3Ni(ε相)或Al3Cu Ni(δ相)转变为Al7Cu4Ni(γ相)其形态从短条状变为网状进而变为环形或半环形形状。此外,采用Thermo-Calc软件定量计算结果与实验结果一致。富镍相的转变对力学性能也有很大影响,在室温条件下拉伸强度由263.8 MPa降低至229.6 MPa,然后增加到278.9 MPa。然而,高温条件下抗拉强度增加了19.7%,但是合金的线性膨胀系数却持续减小。
The evolution of nickel-rich phase in Al-Si-Cu-Ni-Mg piston alloys with different copper contents was analyzed by XRD and thermal field emission (FESEM) The results show that with the increase of Cu content, the phase changes from short strip to reticular and from Al3Ni (ε phase) or Al3Cu Ni (δ phase) to Al7Cu4Ni (γ phase) to become ring or semi-ring shape. In addition, using Thermo-Calc software quantitative calculation results consistent with the experimental results. The transformation of Ni-rich phase also has a great influence on the mechanical properties. At room temperature, the tensile strength decreases from 263.8 MPa to 229.6 MPa and then to 278.9 MPa. However, tensile strength increased by 19.7% at high temperatures, but the linear expansion coefficient of the alloy continued to decrease.