The non-toxic gallium-based liquid metals(LMs) are promising for various newly emerging areas due to having excellent fluidity, high electrical and heat conductivity. However, the oxide layers often affect their appli...The non-toxic gallium-based liquid metals(LMs) are promising for various newly emerging areas due to having excellent fluidity, high electrical and heat conductivity. However, the oxide layers often affect their applications. In this paper, we disclosed a straightforward boiling strategy to efficiently remove the oxide of LM in deionized water. Meanwhile such method was also demonstrated to be capable of quickly breaking up LM into droplets(mean 0.51 mm, SD 0.20 mm) in Na Cl solution,which has important value for manufacture purpose. According to the force analysis, surface tension of LM dominates the interaction between solution bubbles and LM under the same heating conditions. Then we characterized the surface morphology and compositions of LM droplets boiled(LMDB) using scanning electron microscope(SEM), X-ray diffraction(XRD) and Xray photoelectron spectroscopy(XPS) and tested the dynamic force between a rod and LMDB. It was shown that after being boiled in water, most of Ga2O3 was transformed to scattered α-Ga OOH nanorods which has less restriction to the deformation of LM and large resistance force(0.8 mN) was tested;otherwise, after boiled in Na Cl solution, more Ga2 O3 with contact patch structure reduces the surface resistance of LM(0.2 m N) and makes it to be broken up by bubbles. The different surface products are determined by the inhibition of hydrolysis of Ga3+by Na Cl solution. This study paved a simple way for oxide removal in neutral solution and mass production of LMD. It also suggests an efficient approach for exploring mechanisms of interactions between LM and bubbles, which is difficult to study otherwise in sonication.展开更多
The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied a...The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied and related theories are analyzed based on the cutting experiments.The result shows that:(1)the forming processes of cutting direction burr consist of normal cutting,flexure deformation of end surface of workpiece,plastic effect,continuous cutting and shear break separating in orthogonal cutting;(2)a new phenomenon is found that cutting direction burr is formed with the shear break separation of the chip and workpiece machined surfaces;(3)the size of cutting direction burr varies with workpiece materials,cutting parameters and geometric parameters of the cutting tool.展开更多
基金supported by the Dean’s Research Funding,Frontier Funding from Chinese Academy of Sciencesthe National Natural Science Foundation of China(Grant No.91748206)。
文摘The non-toxic gallium-based liquid metals(LMs) are promising for various newly emerging areas due to having excellent fluidity, high electrical and heat conductivity. However, the oxide layers often affect their applications. In this paper, we disclosed a straightforward boiling strategy to efficiently remove the oxide of LM in deionized water. Meanwhile such method was also demonstrated to be capable of quickly breaking up LM into droplets(mean 0.51 mm, SD 0.20 mm) in Na Cl solution,which has important value for manufacture purpose. According to the force analysis, surface tension of LM dominates the interaction between solution bubbles and LM under the same heating conditions. Then we characterized the surface morphology and compositions of LM droplets boiled(LMDB) using scanning electron microscope(SEM), X-ray diffraction(XRD) and Xray photoelectron spectroscopy(XPS) and tested the dynamic force between a rod and LMDB. It was shown that after being boiled in water, most of Ga2O3 was transformed to scattered α-Ga OOH nanorods which has less restriction to the deformation of LM and large resistance force(0.8 mN) was tested;otherwise, after boiled in Na Cl solution, more Ga2 O3 with contact patch structure reduces the surface resistance of LM(0.2 m N) and makes it to be broken up by bubbles. The different surface products are determined by the inhibition of hydrolysis of Ga3+by Na Cl solution. This study paved a simple way for oxide removal in neutral solution and mass production of LMD. It also suggests an efficient approach for exploring mechanisms of interactions between LM and bubbles, which is difficult to study otherwise in sonication.
基金Supported by National Natural Science Foundation of China (No.59775071).
文摘The cutting burr is one of the common phenomena occurring in metal cutting.In this paper,the forming processes,main effect factors and change law of the cutting direction burr in orthogonal cutting have been studied and related theories are analyzed based on the cutting experiments.The result shows that:(1)the forming processes of cutting direction burr consist of normal cutting,flexure deformation of end surface of workpiece,plastic effect,continuous cutting and shear break separating in orthogonal cutting;(2)a new phenomenon is found that cutting direction burr is formed with the shear break separation of the chip and workpiece machined surfaces;(3)the size of cutting direction burr varies with workpiece materials,cutting parameters and geometric parameters of the cutting tool.
