Characteristics of AZ31 Mg alloy joint using automatic TIG welding

The automatic tungsten-inert gas welding（ATIGW） of AZ31 Mg alloys was performed using a six-axis robot. The evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction. The ATIGW process resulted in coarse recrystallized grains in the heat affected zone（HAZ） and epitaxial growth of columnar grains in the fusion zone（FZ）. Substantial changes of texture between the base material（BM） and the FZ were detected. The {0002} basal plane in the BM was largely parallel to the sheet rolling plane, whereas the c-axis of the crystal lattice in the FZ inclined approximately 25° with respect to the welding direction. The maximum pole density increased from 9.45 in the BM to 12.9 in the FZ. The microhardness distribution, tensile properties, and fracture features of the AZ31 auto-welded joints were also investigated.

Progress of research on tetrahydrocurcumin against liver injury

Liver injury has become a serious liver disease worldwide,and its incidence is increasing year by year,bringing a serious health burden to people in all countries.Tetrahydrocurcumin is an active metabolite of curcumin,which has pharmacological effects such as antioxidant,anti-inflammatory,inhibition of apoptosis,anti-tumor,and anti-aging,and it can inhibit apoptosis in liver cells under the state of hepatic injury and reduce the level of oxidative stress and inflammation in liver tissues through the signaling pathways such as MAPK,PI3K/Akt,PPAR,AMPK,and Nrf2 to prevent and control liver injury.The purpose of preventing and controlling liver injury can be achieved.The active structure,pharmacological effects and application of tetrahydrocurcumin in liver injury were summarized by reviewing domestic and international literature,with a view to providing reference for further research on tetrahydrocurcumin in the field of liver injury.

Microstructure and texture evolution of 6016 aluminum alloy during hot compressing deformation

Microstructure and texture in 6016 aluminum alloy during hot compression were researched with a uni- axial compression experiment. Through the electron back- scattered diffraction （EBSD） and X-ray diffraction （XRD） analysis technology, it is shown that the subgrain nucle- ation and recrystallization occur in 6016 aluminum alloy during hot compressing, and strong rolling textures such as （110） fiber texture, Brass, S, and Goss form. With the deformation passes increasing, （110） fiber texture, Brass and S are enhanced. In the heat preservation stage after deformation, recrystallization continues until heat preser- vation for 60 s, and a duplex microstructure of deformation and recrystallization grains is built. At the beginning of heat preservation, recrystallization grains with the Goss texture and random orientation are formed in original grains with S or Brass texture, which makes the volume fraction of S and Brass texture decrease. Then, the complex grain growth process makes the volume fraction of Brass, S, and Goss texture increase, while that of random orien- tation decrease.

Superplasticity of 6016 aluminum alloy at elevated temperatures

The high-temperature plastic deformation be- haviors of 6016 aluminum alloy were investigated with the temperatures ranging from 420 to 540 ℃ and the strain rates ranging from 0.001 to 1.000 s-1. The results show that 6016 aluminum alloys possess superplasticity at 500 ℃ with the strain rates ranging from 0.001 to 0.010 s-1. The grain boundary sliding （GBS） is the main mechanism of superplastic deformation of 6016 aluminum alloy. In addition, a great number of O-type cavities, almost no V type, occur in the microstructure of superplastic deformed 6016 aluminum alloy. The dislocations gather near the grain boundaries to coordinate GBS deformation. The second-phase particles effectively prevent the growth of the recrystallized grains or plastic deformation grains and pin the moving dislocations during deformation.