论文部分内容阅读
采用X射线衍射分析(XRD)、电子背散射衍射分析(EBSD)、电导率测试、硬度测试、晶间腐蚀试验和剥落腐蚀试验,研究了预回复固溶时效处理前的热机械加工(Thermo-mechanical processing,TMP)对超高强铝合金Al-13.01Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr组织及性能的影响。结果表明,TMP(450℃/2 h+460℃/2 h+470℃/2 h(水淬)固溶、400℃/24 h过时效、约45%压缩量)处理后降低了合金的位错密度(0.150→0),减小了平均晶粒尺寸(6.256μm→5.012μm)和平均晶界角度,显著提高了低角度晶界数目百分比(0.618→0.700),电导率(25.3%IACS→27.2%IACS)和伸长率(8.1%→8.2%)基本未发生变化,降低了硬度(229.6 HV→221.0 HV)、屈服强度(653.8 MPa→599.5 MPa)、抗拉强度(701.9 MPa→646.3 MPa),提高了抗晶间腐蚀和抗剥落腐蚀性能。定量分析显示,热机械加工轻微提高了合金位错强化、低角度晶界强化和高角度晶界强化的总强化,合金强度的降低主要归因于合金固溶强化和时效沉淀析出相强化的总强化的降低。抗腐蚀性能的提高可以归因于合金低角度晶界数目百分比的提高。
X-ray diffraction (XRD), electron backscatter diffraction (EBSD), conductivity test, hardness test, intergranular corrosion test and exfoliation corrosion test were used to study the effect of Thermo- Mechanical Processing, TMP) on microstructure and properties of Al-13.01Zn-3.16Mg-2.8Cu-0.2Zr-0.07Sr ultra-high strength aluminum alloy. The results show that the TMP (450 ℃ / 2 h + 460 ℃ / 2 h + 470 ℃ / 2 h (water quenching) solution, 400 ℃ / 24 h overage, about 45% (0.150 → 0), the average grain size (6.256μm → 5.012μm) and average grain boundary angle were reduced, and the percentage of low angle grain boundaries (0.618 → 0.700), conductivity (25.3% IACS → 27.2% IACS) and elongation (8.1% → 8.2%), the hardness (229.6 HV → 221.0 HV), yield strength (653.8 MPa → 599.5 MPa) and tensile strength (701.9 MPa → 646.3 MPa) , Improved resistance to intergranular corrosion and anti-spalling corrosion. Quantitative analysis showed that thermal mechanical processing slightly increased the total dislocation strengthening, low angle grain boundary strengthening and high angle grain boundary strengthening of the total strengthening, the reduction of the alloy strength is mainly due to the alloy solution strengthening and aging precipitated phase strengthening total Strengthen the reduction. The improvement of the corrosion resistance can be attributed to the increase of the percentage of the number of low-angle grain boundaries in the alloy.