Moustafa Essam B, Alazwari Mashhour A, Abushanab Waheed Sami, Ghandourah Emad Ismat, Mosleh Ahmed O, Ahmed Haitham M, Taha Mohamed A
Mechanical Engineering Department, Faculty of Engineering, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Marine Engineering Department, Faculty of Maritime Studies and Marine Engineering, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Materials (Basel). 2022 Jan 22;15(3):835. doi: 10.3390/ma15030835.
In this study, two successive methods were used to improve the grain structure and the mechanical and physical properties of Al 5052 aluminum alloy. The modifying elements, 0.99 wt.% of titanium (Ti) and 0.2 wt.% of boron (B), were added during the casting process. After solidification, single- and double-pass friction stir processing (FSP) were performed to achieve additional grain refinement and disperse the newly formed phases well. The addition of Ti-B modifiers significantly improved the mechanical and physical properties of the Al 5052 aluminum alloy. Nevertheless, only a 3% improvement in microhardness was achieved. The ultimate strength (US), yield strength (YS), and elastic modulus were investigated. In addition, the electrical conductivity was reduced by 56% compared to the base alloys. The effects of grain refinement on thermal expansion and corrosion rate were studied; the modified alloy with Ti-B in the as-cast state showed lower dimension stability than the samples treated with the FSP method. The grain refinement significantly affected the corrosion resistance; for example, single and double FSP passes reduced the corrosion rate by 11.4 times and 19.2 times, respectively. The successive FSP passes, resulting in a non-porous structure, increased the bulk density and formed precipitates with high bulk density.
在本研究中，采用了两种连续的方法来改善5052铝合金的晶粒结构以及力学和物理性能。在铸造过程中添加了变质元素，钛（Ti）含量为0.99 wt.%，硼（B）含量为0.2 wt.%。凝固后，进行了单道次和双道次搅拌摩擦加工（FSP），以实现进一步的晶粒细化并使新形成的相均匀分散。添加Ti-B变质剂显著改善了5052铝合金的力学和物理性能。然而，显微硬度仅提高了3%。对极限强度（US）、屈服强度（YS）和弹性模量进行了研究。此外，与基体合金相比，电导率降低了56%。研究了晶粒细化对热膨胀和腐蚀速率的影响；铸态含Ti-B的变质合金比采用FSP方法处理的样品显示出更低的尺寸稳定性。晶粒细化对耐蚀性有显著影响；例如，单道次和双道次FSP分别使腐蚀速率降低了11.4倍和19.2倍。连续的FSP道次形成了无孔结构，提高了体积密度并形成了具有高体积密度的析出物。
