RESUMEN
An inhomogeneous microstructure induced by high rotating speed submerged friction stir processing (HRS-SFSP) on 6061 aluminum alloy was researched in detail.The microstructures of the aluminum alloy processing zone were characterized by electron backscattered diffraction (EBSD) and transmission electron microscope (TEM) qualitatively and quantitatively.The results show that the recrystallization proportion in the inhomogeneous structure of the processing zone is 14.3%, 37.8% and 35.9%, respectively. Different degrees of grain deformation can affect the dislocation and lead to the formation of a plastic-elastic interface. At the same time, the second-phase particles in the processing zone were inhomogeneity and relatively, which further promotes the plastic-elastic interface effect. The plastic-elastic interface can significantly improve the strength of aluminum alloy, whileat the same time, rely on recrystallized grains to provide enough plasticity. When the rotation speed was 3600 r/min, the strength and ductility of the aluminum alloy after HRS-SFSP were increased by 48.7% and 10.2% respectively compared with that of BM. In all, the plastic-elastic interface can be formed by using high rotating speed submerged friction stir processing, and the strength-ductility synergy of aluminum alloy can be realized at the plastic-elastic interface.
RESUMEN
OBJECTIVE: To provide the proof for establishing the high throughput screening method of the acute toxicity by comparing the 4 screening methods of the acute toxicity in vitro. METHODS: HepG2 cells, plated in 96-well plates, were treated with 47 compounds and we detected the cytotoxicity using 4 methods and calculated the IC50, IC45, IC40, IC35, IC30, and these values were compared with the LD50. RESULTS: The IC45 from the neutral red method has the best relativity with the LD50. CONCLUSION: Plating HepG2 cells in 96-well plates, the cytotoxicity be detected using the neutral red method and the IC45 was calculated. It is considered to provide the proof for establishing the high throughput screening method of the acute toxicity in vitro.
