Jian Qin

5xxx series Al─Mg─Mn alloys are known for their excellent corrosion resistance. However, when the Mg content exceeds 3.5 wt.%, the corrosion resistance deteriorates significantly. This study elucidates how Si, as an alloying element, enhances the corrosion resistance of 5xxx aluminum alloys by influencing the precipitation of dispersoids. The addition of Si significantly accelerated the precipitation kinetics of dispersoids through two main mechanisms: first, by providing heterogeneous nucleation sites via metastable Mg ₂ Si precipitates for α‐Al(Mn, Fe)Si and Al _x (Mn, Fe) dispersoids; and second, by promoting the formation of α‐Al(Mn, Fe)Si dispersoids, which precipitate more actively than the Al _x (Mn, Fe) phase. Results from the nitric acid mass loss test and potentiodynamic polarization curves demonstrated a significant improvement in corrosion resistance in the Si‐modified alloy. Microstructural analysis revealed that in the Si‐free alloy, the Al ₃ Mg ₂ phase formed a continuous grain‐boundary network, which acted as a pathway for intergranular corrosion. In contrast, in the Si addition alloy, dispersoids disrupted this continuous network. Furthermore, in Si‐modified alloy grain‐boundary precipitation of Al ₃ Mg ₂ is likely restricted owing to local sequestration of solute Mg within grains via two microstructural pathways: heterogeneous nucleation of intragranular Al ₃ Mg ₂ on dispersoids and formation of metastable Mg ₂ Si precipitates along dislocation tangles stabilized by dispersoids.

1. SiC reinforced Al matrix composites have been widely utilised in many industries, including automotive, electronics, machinery, marine, and aviation, due to their low density, high strength, hig...

Fasting therapy of Chinese Medicine was put forward by Professor Qin Jian based on the theory of fat and grease from The Yellow Emperors Internal Classi and modified on the basis of Buchinger fasting therapy. Here we try to report a female patient with the chief complaint of arthralgia who was diagnosed as rheumatoid arthritis, non-alcoholic fatty liver disease and suspected type 2 diabetes mellitus, also diagnosed by Chinese medicine with Bi disease of spleen deficiency and phlegm dampness syndrome. After admission, the patient was treated with fasting therapy of Chinese Medicine for a week. Considering that she was in the menstrual period, she was given a very-low-calorie diet during that time. Moreover, she was given L-carnitine injection, health education and traditional Chinese medicine treatment, including foot massage, acupuncture and acupoint application everyday. After discharge, she was asked to take low-calorie diet and modified Linggui Zhugan Decoction for another week. After that, she followed the doctor's instructions for long-term caloric control. A year later, the reexamination showed that her condition was improving.

The hot deformation behaviors of homogenized direct‐chill (DC) casting 6061 aluminum alloys and Mn/Cr‐containing aluminum alloys denoted as WQ1 were studied systematically by uniaxial compression tests at various deformation temperatures and strain rates. Hot deformation behavior of WQ1 alloy was remarkably changed compared to that of 6061 alloy with the presence of α‐Al(MnCr)Si dispersoids. The hyperbolic‐sine constitutive equation was employed to determine the materials constants and activation energies of both studied alloys. The evolution of the activation energies of two alloys was investigated on a revised Sellars’ constitutive equation. The processing maps and activation energy maps of both alloys were also constructed to reveal deformation stable domains and optimize deformation parameters, respectively. Under the influence of α dispersoids, WQ1 alloy presented a higher activation energy, around 40 kJ/mol greater than 6061 alloy’s at the same deformation conditions. Dynamic recrystallization (DRX) is main dynamic softening mechanism in safe processing domain of 6061 alloy, while dynamic recovery (DRV) was main dynamic softening mechanism in WQ1 alloy due to pinning effect of α‐Al(MnCr)Si dispersoids. α dispersoids can not only resist DRX but also increase power required for deformation of WQ1 alloy. The microstructure analysis revealed that the flow instability was attributed to the void formation and intermetallic cracking during hot deformation of both alloys.