Papers by Author: Chun Li

Abstract: In this paper, based on the liquid forging part flange LY12, the influence of specific pressure on the organization and performance of the liquid forging part was studied through microstructure, mechanical properties and tensile fracture surface analysis methods, this article also has some guiding significance to the formulation of the best liquid forging process parameters. The results show that the tensile strength, hardness and elongation of the parts raise with the specific pressure increasing, the organization has also been significant refinement and improvement.

Abstract: In this paper, we introduce the squeeze casting process to produce flange. This article also introduces the optimized roughcast of flange, the cruces of the die design, the main structure parameters and the working traits of the die. The result shows that using squeeze casting method to produce flange not only can get the qualified part, which also greatly increase the material utilization together with enormously save processing time and processing costs at the same time.

Abstract: Based on the oxygen ion conductor La2Mo1.5W0.5O9, a series of Ag2O doped samples La2Mo1.5W0.5O9/Ag were prepared with conventional solid-state reaction method. The effects of Ag2O doping on the microstructure and electrical conductivity have been investigated by XRD, FESEM and direct current conductivity measurements. With the increase of Ag2O doping, the grain was further refined and compacted, meanwhile, Ag diffusion distribution in the form of second-phase appear at grain boundary. The sample density and conductivity also gradually increased with the increasing of doping amount. The conductivity of the composite specimen La2Mo1.5W0.5O9 /Ag has a great enhancement when the concentration of Ag2O is around 27 wt%, which is eight times higher than that of the single-phase sample.

Abstract: Based on the oxygen ion conductor La1.95K0.05Mo2O8.95, a series of Fe-doped samples La1.95K0.05Mo2-xFexO9- (x=0, 0.025, 0.05, 0.1) were prepared with conventional solid reaction method. The effects of Fe doping on the structure, oxygen ion diffusion and electrical conductivity were studied. Based on the results of conductivity measurements, it can be concluded that Fe doping can improve the conductivity obviously, and doping of both Fe and K samples have better conductivity, which successfully suppresses the phase transition.

Abstract: In this paper, we introduce an mathematical theory model of ultrasonic breaking up dendrite through the experiment of put ultrasonic vibration on melting A356, which is based on the condition of the effect factors of particles compelled movement on crystal integrality. It can be seen that two factors are very importment to crushing the grain through ultrasonic vibration, namely, structure conditions of the grain growth and the dynamic conditions provided by the ultrasonic. The driving force provide by the ultrasonic can be direct alternating mechanical force and the second, third and so on sound wave force caused by ultrasound wave reflection, scattering etc.. Form the model we can found that the larger the ultrasonic power and amplitude, conditions can be more easily satisfied; simlarly the higher the ultrasonic frequency, angle crossing number, grain structure defects, the longer action time to make greater fatigue, all this factors can also make the conditions more easily satisfied.