Ti对新型耐热铝合金微观组织和高温力学性能的影响

Effect of Ti on microstructure and high temperature mechanical properties of new type heat-resistemt aluminum alloy

为研究Ti对Al-5.3 Cu-3.1 Ni-1.2 Mg-0.3 Sc-0.2 Zr合金微观组织和高温力学性能的影响,采用坩埚电阻炉熔炼制备新型铝合金,利用扫描电子显微镜、X射线衍射仪分析微观组织及相组成,测试其高温拉伸力学性能。结果表明:添加质量分数1%的Ti后,合金基体上出现块状的Al_(3)(Zr_(1-x)Ti_(x))相,随着Ti元素质量分数增加,Al_(3)(Zr_(1-x)Ti_(x))相数量增加,并趋于团聚,其屈服强度得到明显提高,达到208 MPa,伸长率为2.7%;当添加Ti的质量分数为2%、3%时,其屈服强度分别为179、171 MPa,伸长率分别为2.2%、1.5%;Ti的质量分数超过1%时,合金的屈服强度和塑性均呈下降趋势。

This paper aims to investigate the effect of different mass fractions of Ti on the microstructure and high temperature mechanical properties of Al-5.3Cu-3.1Ni-1.2Mg-0.3Sc-0.2Zr alloy.The study involves preparing new aluminum alloy using crucible resistance furnace smelting;and investigating the microstructure and high temperature mechanical properties using scanning electron microscopy,X-ray diffraction and universal testing machine.The results show that the addition of Ti with mass fraction of 1%,massive Al_(3)(Zr_(1-x)Ti_(x))is followed by the occurrence of phase on the alloy matrix;along with the increase of Ti mass fraction comes a significant increase in the number of Al_(3)(Zr_(1-x)Ti_(x))phase,with a tendency to agglomerate,resulting in a significant improvement in the high-temperature yield strength of Al-5.3Cu-3.1Ni-1.2Mg-0.3Sc-0.2Zr-Ti alloy,with up to 208 MPa,and with the elongation of 2.7%;the presence of the mass fraction of Ti of 2%,3%means the yield strength of 179,171 MPa and the elongation of 2.2%,1.5%;and the mass fraction of Ti more than 1%,is followed by a downward trend in the yield strength and plasticity of the alloy.