Al-Cu-Ce合金的微观组织与力学性能

采用X射线衍射、金相显微镜、扫描电镜、能谱分析及拉伸性能测试等方法,研究3种成分Al-Cu-Ce合金的显微组织与力学性能。结果表明:铸态Al-14Cu-7Ce合金由α-Al+Al8CeCu4片状共晶组成,而Al-10Cu-5Ce、Al-18Cu-9Ce合金中除含有α-Al+Al8CeCu4共晶组织外,还分别含有α-Al和Al8CeCu4初生相。铸态Al-14Cu-7Ce合金具有优良耐热性能,即使550℃×3 h退火后仍能保持约360 MPa的抗拉强度,退火导致合金强度下降的主要原因是高温下共晶Al8CeCu4相的球化。经充分球化退火后,Al-Cu-Ce合金能获得良好的热轧、冷轧变形能力,并且变形态合金也具有良好的耐热性能,因而Al-Cu-Ce合金有望成为一种兼具铸造和变形两用的新型耐热铝合金。

Microstructure and mechanical properties of Al-Cu-Ce alloy

Microstructure and mechanical properties of Al-Cu-Ce alloys with different Cu and Ce contents were investigated by means of X-ray diffraction(XRD),optical microscope(OM),scanning electron microscopy(SEM),energy dispersive spectrometer(EDS) and mechanical property testing.The results show that the microstructure of Al-14Cu-7Ce alloy consists of α-Al+Al8CeCu4 eutectic.But for Al-10Cu-5Ce and Al-18Cu-9Ce alloys,the primary phases of α-Al and Al8CeCu4 are also found,respectively,besides α-Al+Al8CeCu4 eutectic.The as-cast Al-14Cu-7Ce alloy exhibits excellent heat resistance,the tensile strength of which remains about 360 MPa after annealing at 550 ℃ for 3 h.The decrease of strength is observed in the alloy after annealing at higher temperature or for longer time because of the spheroidization of the eutectic Al8CeCu4 phase.A combination of good hot and cold plastic working ability with higher heat resisfance can be obtained for the Al-Cu-Ce alloys after spheroidization annealing.