添加Er-TiB2双相纳米颗粒对激光粉末床熔融制备Al-Mn-Mg-Sc-Zr合金强度-韧性的影响

Effect of Addition of Er-TiB2 Dual-Phase Nanoparticles on Strength-Ductility of Al-Mn-Mg-Sc-Zr Alloy Prepared by Laser Powder Bed Fusion

摘要:

采用双相协同增强的方法，利用Er和TiB₂的特有优势对激光粉末床熔融（LPBF）制备的Al-Mn-Mg-Sc-Zr合金进行强化。采用真空均质技术制备了0.5wt% Er-1wt% TiB₂/Al-Mn-Mg-Sc-Zr纳米复合材料的球形粉末，LPBF工艺制备的样品密度达到99.8%。探讨了Er-TiB₂的强化机理和增韧机理。结果表明，XRD分析存在Al₃Er衍射峰，EBSD结果显示双相纳米颗粒添加后合金织构强度下降。添加的Er和TiB₂纳米增强相在LPBF形成过程中起非均相形核作用，阻碍晶粒长大，可有效细化晶粒。添加Er和TiB₂双相纳米增强相后，LPBF成形样品的抗拉伸强度和延伸率分别达到550 MPa和18.7%，相较基体材料提高13.4%和26.4%。

Abstract:

A dual-phase synergistic enhancement method was adopted to strengthen the Al-Mn-Mg-Sc-Zr alloy fabricated by laser powder bed fusion (LPBF) by leveraging the unique advantages of Er and TiB₂. Spherical powders of 0.5wt% Er-1wt% TiB₂/Al-Mn-Mg-Sc-Zr nanocomposite were prepared using vacuum homogenization technique, and the density of samples prepared through the LPBF process reached 99.8%. The strengthening and toughening mechanisms of Er-TiB₂ were investigated. The results show that Al₃Er diffraction peaks are detected by X-ray diffraction analysis, and texture strength decreases according to electron backscatter diffraction results. The added Er and TiB₂ nano-reinforcing phases act as heterogeneous nucleation sites during the LPBF forming process, hindering grain growth and effectively refining the grains. After incorporating the Er-TiB₂ dual-phase nano-reinforcing phases, the tensile strength and elongation at break of the LPBF-deposited samples reach 550 MPa and 18.7%, which are 13.4% and 26.4% higher than those of the matrix material, respectively.